EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 … · 2018-10-30 · TDBFP - Operating floor and MDBFP - 0.0 M Floor. The provision as per bidding specification shall prevail

Sl. No. Volume No. Section/Chapter No. Clause no. Description as per tender document Query from BIDDER Owner's Reply

1 Volume-III Chapter-26 Clause no. 27.5.4 Pipelines of NB 50 size and below are regarded as field run piping. It is Bidder’s responsibility to plan suitable layouts for these system insitu.Bidder shall prepare drawings indicating the layout of field run pipe work.These drawings shall be approved by Project Manager to the installation of the field run pipe work. Based on these approved layouts, the Bidder shall prepare the BOQ of field run-pipe and submit to Customer for approval.

For site routed pipes (50Nb & below), routings are decided & done at site suitably to suit site conditions. Hence, as per bidder’s practice no layout drawings are made. But necessary guidelines for site routed piping will be issued to our site counterpart at contract stage. Kindly confirm.

Confirmed.

2 Volume-III Chapter-26 Clause no. 26.14.3 b) Binding & lacing wire:Galvanized steel wire to IS:280 for temp. below 400 deg. C and stainless steel to IS: 6528 for temp. above 400 deg. C.

The temperature mentioned in the referred clause should be interface temperature as per IS:14164.The same has been mentioned for straps & bands, hexagonal wire mesh etc. in tender documents.Please confirm.

Confirmed.

3 Volume-III Chapter-26 Clause no. 26.14.4 b) Where insulation is applied in two or more layers each layer of mattress shall be backed with hexagonal wire mesh. For the first layer of insulation and in case of single layer insulation, hexagonal wire mesh shall be provided on both the surface of the mattress. For pipe sections, the sections shall be held in place by binding wires without any wire mesh.

The insulation will be backed with hexagonal wire mesh on only outer side of each layer as per IS:14164 and the same is followed in our earlier executed projects. Please confirm.

Confirmed.

4 Volume-III Chapter-26 Clause no. 26.14.4 a) Cladding...20 SWG (0.91 mm) for diameter for insulated surfaces of 150 mm & above and above up to 450 mm…

Thickness of sheathing for diameter for insulated surfaces of less than 150 mm is not mentioned in tender specification. We understand it will be 22 SWG (0.711mm). Please confirm.

Confirmed.

5 Volume-III Chapter-2 Clause no. 7.9 Location of TDBFPs & MDBFPTDBFPs to be preferably located on operating floor and MDBFP to be located on ground floor (0.0M).

Location shown in Layout Dwg.(Vol VII TD Layout)

Both Clauses are contradictory.

Bidder proposes to locate TDBFP at intermittant floor (approx. 5.0M). Please confirm your acceptance.

TDBFP - Operating floor and MDBFP - 0.0 M Floor. The provision as per bidding specification shall prevail.

6 Volume-III Chapter-33 Clause no. 33.4.14, 33.4.31.VIII 33.4.14 Equipment Layout:Clear Head room within Main Plant Building for pipes, ducts, structures & cable trays etc. - 2.5m (Minimum).

33.4.31.VIII Equipment Layout:Head room for man movement shall be minimum 2.5m at ground floor in TG and boiler area and 2.1m over all platforms.

Inside TG Building, minimum 2.1M head room for man movement is sufficient and is followed in our earlier executed projects of various reputed customers. Kindly confirm.

The provision as per bidding specification shall prevail.

7 Volume-III Chapter-33 Clause no. 33.4.31 i), 6.05.00 33.4.31 i)Trestle height in outlying area shall be 5.0 M (BOS).6.05.00Cable & Pipe rack (except at road and rail crossings)- 3000 mm

There is contradiction in two clauses. Bidder is considering cable& pipe rack height in outlying area as 3.0M (BOS). Please confirm.

Shall be 5.0 M (BOS).

EPC PACKAGE FORBUXAR THERMAL POWER PROJECT (2 X 660 MW)

PREBID CLARIFICATIONS-3Dated: 29.10.2018

A. BOP AREA

PAGE 1 OF 78



PREBID CLARIFICATIONS-3Dated: 29.10.2018

8 Volume-III Chapter-33 Clause no. 33.8 Bidder's shall prepare the detailed layout of main power block area indicating the location of all major equipments. The layout shall be furnished along with the bids submitted by the bidder.

Bidder understand that TG Building size will be decided/ optimized by bidder based on their offered equipment. However customer is requested to specify minimum re-quirement of TG Building (i.e. width, height & length).

Please refer Drg Nos.:111-21-0200, 111-21-0300, 111-21-0400, 111-21-0600, 111-21-0700For length, width & hight as min.

9 Volume-III Chapter-10 - Not specified. Hotwell make-up pumps, Boiler/ deaerator fill pumps and DM transfer/ DM cycle make-up pumps shall be located under all side open shed. Please confirm.

Shall be located in a building with RCC roof & side walls.

10 Volume-III, Volume-VI

Chapter-4, Chapter-6 Clause no. 4.1, 6.17.00 1) 4.1 The distance from raw water intake structure to raw water reservoir shall be assumed as 9000 M.6.17.00 1) :-Pipe line route about 6.00 km in length.

Raw water intake pipe line length is contradicting. Kindly confirm and provide the suggestive routing for the same.

Length of Raw Water Pipeline from intake to plant boundary is about 6.0 KM.

11 Volume-IV CH-1/ 1.18.02/ 19 OF 48

Cl. No.-1.18.02/ 19 OF 48 There shall be 6 station Switchgears for three units. May please clarify regarding no of units and switchgear. 2 Units with 4 Nos. 11 kV Station Switchgear

12 Volume-IV CH-1/ 1.29.01/ 32 OF 48

CH-1/ 1.29.01/ 32 OF 48 Three sets of above 220 V DC Systems shall take care of DC loads of 3 units and DC loads of station system.

2 sets of DC systems to cater to DC loads of 2 units . Each set shall comprise of 2 x 100% battery and each battery shall have 2x100% FCBC

Agreed.

13 Volume-IV 1.09.05/ 13 OF 48&IV/ CH-1/ 1.30.12/ 35 OF 48

IV/ CH-1/ 1.09.05/ 13 OF 48&IV/ CH-1/ 1.30.12/ 35 OF 48

HT & LT power cables shall be laid in ladder type cable trays. Control & Instrumentation cables shall be laid in perforated trays.& HV & MV cables & LV power cables shall be laid in ladder type cable trays. Control & Instrumentation cables shall be laid in perforated trays.

MV, LV power cables, Controls cables shall be laid in Ladder trays and Instrumentation cables shall be laid in Perforated Trays.

Power Cables shall be laid in ladder type trays. Control and I&C cables shall be laid in perforated trays.

14 Volume-IV CH-3/ 3.01.07/ 2 OF 42

Cl. No. 3.01.07/ 2 OF 42 One fabricated oil storage tank common for three (3) units suitable for 40 kilo litres of oil. May please clarify regarding no of units & tanks. One tank common for 2 units.

15 Volume-IV CH-5/ 5.16.01/ 17 OF 19

Cl. No. 5.16.01/ 17 OF 19 LV Phase CT in LV Turret of Transformer For restricted earth fault protection, the LV Phase CT may also be permitted in the Switchgear.


16 Volume-IV CH-20/ 20.05.02/ 6 OF 21

Cl. No. 20.05.02/ 6 OF 21 Support system of Cable Trays Cable tray support system is not specified. Kindly inform whether cable tray system is boltable type or welded type.

cable tray should be as per latest standard/Practice followed by Super critical thermal Power Projects.

17 Volume-IV CH-23/ 23.09.05/ 9 OF 30

Cl. No.-23.09.05/ 9 OF 30 T5 Lamps T5 lamps may not be applicable for LED lighting Fixtures. Only LED fixtures to be provided.

18 Volume-IV CH-23/ 23.09.06/ 9 OF 30

Cl. No.-23.09.06/ 9 OF 30 Ballast Ballast may not be applicable for LED lighting Fixtures Agreed.

Electrical

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PREBID CLARIFICATIONS-3 Dated: 29.10.2018

19 Tender Drawings Customer SLD for SWBDsa) 112-01-1206b) 112-01-1202c) 112-01-1204d) 112-01-1205e) 112-01-1200 etc.

Ratings specified Tender document contains Ratings of all Transformers like BST, TST, ESPTs etc. Kindly specify that these ratings are fixed or are min values or Bidder has the flexibility to decide the ratings. Similarly the electrical distribution for SWBDs has been shown in the SLDs. Customer may please inform that the electrical distribution informed is fixed or bidder has the flexibility to design the electrical system distribution.

SLD shown the minimum rating of transformer. SLD shows the minimum switchboards. If any additional switchboard is needed as per geographical location can be provided.

20 Volume-IV Ch-22 : Battery & BatteryChargerPage 4 of 22

Cl. No. 1.29.00/ 32 OF 48 DC System for Offsite Batteries Configuration for Offisite Batteries is not defined in the specification. Bidder proposes 2x100% Battery with 1 charger per battery for offsite system. Also, min Battery size for offsite battery system is not defined as mentioned for Main plant battery in the datasheet.

For BOP 2x100% battery. Each Battery shall have one(1) FCBC and one common standby charger. Minimum capacity of battery is 200 AH.

21 Volume-IV CH-1/ 1.02.08/ 3 OF 48

Cl. No. 1.02.08/ 3 OF 48 Purchaser's Feeder for Intake PumpHouse Scope of Electrical System for Intake Pumphouse is not clear. Please clarify whether bidder's scope ends at uncabled feeders for Intake Pumphouse or the complete electricals including transformers are in bidder's scope. If it in bidder's scope Bidder proposes Overhead wire for power supply from Main plant to Raw Water Intake Transformers -A & B. Please confirm.

Complete electricals of Intake Pumphouse is in Bidders scope.

22 Volume-IV CH-1/ 1.02.15/ 4 OF 48

Cl. No. 1.02.15/ 4 OF 48 Trenches Cable trenches may be allowed in Transformer yard and for interconnection with Switchyard.

Agreed.

23 Volume-IV CH-1/ 1.02.17/ 4 OF 48

Cl. No. 1.02.17/ 4 OF 48 Submat Submat shall be provided in Switchgear Rooms. Agreed.

24 Volume-IV CH-1&CH-32

Cl. No. 1.12.01/ 16 OF 48&Cl. No. 32.02.00/ 2 OF 13

Generator Protection 100% Redundancy shall be provided for Generator Protections, however redundancy is not envisaged for GT, UT, because of space constraint in accomodating multiple CTs in bushings.

Agreed.

25 Volume-IV CH-1/ 1.12.03/ 16 OF 48

Cl. No. 1.12.03/ 16 OF 48 GRP, STRP Protections for Station Transformer shall be provided in a dedicated separate Station Transformer protection panel.

Agreed.

26 Volume-IV CH-1/ 1.13.01/ 18 OF 48

Cl. No. 1.13.01/ 18 OF 48 GT - One spare for 3 units One spare single Phase GT shall be provided for 2 Units. Agreed.

27 Volume-IV CH-1/ 1.25.02/ 25 OF 48

Cl. No. 1.25.02/ 25 OF 48 Differential Protection - Auxiliary Transformers Differential Protection shall be provided for transformers ≥ 5MVA. Agreed.

28 Volume-IV CH-1/ 1.25.04/ 26 OF 48

Cl. No. 1.25.04/ 26 OF 48 Differential Protection - HV & MV Motors Differential Protection shall be provided for HV&MV Motors ≥ 1000KW. Agreed.

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29 Volume-IV CH-1/ 1.25.05 k)/ 29 OF 48

Cl. No. 1.25.05 k)/ 29 OF 48 Electronic Energy Meters for Incomer of ACDB/MLDB/PDB/MCCB As per 1.26.05 a), Energy meters are to be provided only for Incomers of PMCC & MCC rated 630A and above. Hence they are not envisaged for Incomer of ACDB/MLDB/PDB/MCCB


30 Volume-IV IV/ CH-1/ 1.27.04 / 30 OF 48

Cl. No. 1.27.04 / 30 OF 48 Starting Current for EE motors Starting current of LV Energy Efficient motors shall be as per IS12615. Agreed.

31 Volume-IV CH-1/ 1.29.01 / 32 OF 48

Cl. No. 1.29.01 / 32 OF 48 Starting Time for DC Drives Starting time of DC drives shall be as per OEM recommendation Agreed.

32 Volume-IV CH-1/ 1.29.01 g) / 33 OF 48

Cl. No. 1.29.01 g) / 33 OF 48 DC Health Monitoring system - Areas not specified in the specification Please clarify for which all battery systems Health Monitoring Systems is required. In absence of clarity, bidder proposes to provide DC Health Monitoring system for Main plant battery only.

For all areas.

33 Volume-IV CH-1/ 1.33.01 a) / 36 OCl. No. 1.33.01 a) / 36 OF 48 Termination & Jointing Kits Termination & Jointing Kits are not applicable for LV Cables Agreed.

34 Volume-IV CH-1/ 1.33.01 a) / 36 OF 48&Annexure-1 Chapter-23

Cl. No. 1.33.01 a) / 36 OF 48&Annexure-1 Chapter-23

Mismatch in Chapter 1 - LED & Chapter-23 (Conventional Type Lighting Fixtures) We understand that LED type fixtures shall be provided for Entire plant, Accordingly specification for Conventional Type fixtures in Chapter-23 are not applicable.

Agreed.

35 Volume-IV CH-1/ 1.43.01 / 42 OF 48

Cl. No. 1.43.01 / 42 OF 48 One more emergency dieselgenerator shall be provided to act as standby for three units.

One Standby dieselgenerator shall be provided to act as standby for 2 units.

Total 3 Nos. DG sets one for each unit and 1 common standby to be provided.

36 Volume-IV CH-3/ 3.03.02 / 5 OF 42

Cl. No. 3.03.02 / 5 OF 42 Station Transformer Sizing Station Transformer shall be sized to cater to the Total station load + Start up load of one unit including MDBFP.OR Total station load + shutdown load of one unit WHICHEVER is HIGHER.


37 Volume-IV CH-3/ 8.01.10 / 3 OF 36

Cl. No.-8.01.10 / 3 OF 36 Incomers from all the Unit Transformers & Station Transformers shall beprovided with Lightning Arrestor 11kV side.

LA is not required in the Incomers of UT & ST as LA are already provided in the HV side of the Transformers.


38 Volume-IV CH-14/ 14.37.02 / 14 OF 20

Cl. No. 14.37.02 / 14 OF 20 3 Core Cables for HV & MV Motors Single Core Cables shall also be used for HV & MV Motors. Single core cable to be used above 400 sq.mm cable.

39 Volume-IV CH-17/ 17.06.08 / 10 OF 11

Cl. No. 17.06.08 / 10 OF 11 HV cables shall be pressure tested (test voltage as per IS:7098) before commissioning.

Customer to specify that by Pressure test Hi Pot test only is sought. The provision as per bidding specification shall prevail.

40 Volume-IV CH-18/ 18.04.02 / 6 OF 12

Cl. No. 18.04.02 / 6 OF 12 For Single core cables to be used in A.C system, thearmouring over inner sheath shall consist of single layer ofround copper wire.

Aluminum armour shall be provided for Single core Fire Survival cables The provision as per bidding specification shall prevail.

41 Volume-IV CH-20/ 20.05.06 / 7 OF 21

Cl. No. 20.05.06 / 7 OF 21 Straight Through Joint for LV Cable Straight Through joints are not applicable for LV Cables Agreed.

42 Volume-IV CH-22/ 22.04.12 / 5 OF 22

Cl. No. 22.04.12 / 5 OF 22 Battery Sizing - Derating Factor Derating Factor for Prolonged Float Charging is not applicable for Lead Acid Batteries.

Agreed.

PAGE 4 OF 75




43 Volume-IV CH-23/ 23.02.01 iii) / 2 OF 30

Cl. No. 23.02.01 iii) / 2 OF 30 Energy Saving system Energy Saving system is not required for LED Fixtures. Agreed.

44 Volume-IV CH-23/ 23.09.20 / 15 OF 30

Cl. No. 23.09.20 / 15 OF 30 Wire size from LP to Junction Box - 10 sq mm Wire size from LP to Junction Box - 2.5 sq mm Agreed.

45 Volume-IV CH-26/ 1 OF 22 IV/ CH-26/ 1 OF 22 Accuracy, Range & Class of Equipments Details mentioned in the specification shall only be used as reference. Accuracy, Range & other features shall be finalized during the detailed engineering.

Agreed.

46 Volume-IV CH-32/ 32.07.27 iii / 12 OF 13

Cl. No. 32.07.27 iii / 12 OF 13 Hardwired illuminated lamps with push buttons (ILPBs for the startoperation of following:-a) DC-EOPc) Emergency BFPd) DC ESOP

Shall be a part of UCP (C&I) The provision as per bidding specification shall prevail.

46(a) Volume-IV CH-3 3.01.02 / 2 OF 42

IV/ CH-3/ GENERATOR TRANSFORMER DATASHEET 1.6 / 37 OF 42

ESLD sheet 1 of 2 , drg no. 112-10-0100

GT HV VOLTAGE400/√3OR420/√3OR765/√3

Customer to specify the exact GT HV Voltage. 400 kV

46(b) Volume-IV CH-3 GENERATOR TRANSFORMER DATASHEET 1.15 / 37 OF 42

GT Impedance - 15% (max) on 275 MVA base withoutpositive tolerence

GT Impedance value shall be decided during detailed engineering based on the fault level of busduct.

Confirmed.

46(c) Volume-IV Mechanical - Cathodic Protection Bidder understands that, (if required) sacrificial type of cathodic protection is sought.

Confirmed.

47 Volume-V Part-B/Chapter-1 1.04.00 Standardization and Uniformity of HardwareBidder shall ensure that various C&I instruments /equipment like vibration monitoring system, 4-20mA electronic transmitters / transducers, Temperature elements and other instruments/ local devices etc. that are being furnished by the bidder, are of the same make, series and family of hardware so as to ensure smooth and optimal maintenance, easy interchangeability and efficient spare parts management.

As per BIDDER policy, C&I equipments will be procured from BIDDER approved vendor list and single make may not be possible. However BIDDER shall put all efforts in minimizing the type of makes.

Please accept.

Agreed.

48 Volume-V Part-B/Chapter-6 6.19.03 Item (a) to (e) referred above at cl. No. 6.19.01 shall be mounted in an airconditioned control room having false roof and false flooring.

False flooring for control equipment room is not envisaged as cable spreader room is envisaged below the EER. For offsite control rooms,cable trench shall be provided for cable routing purpose.Please accept.

Agreed.

Control & Instrumentation

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49 Volume-V Part-B/Chapter-11 11.02.05 The control valve indiced noise shall be limited to 85 dBA at 1 meter from the valve surface under actual operating conditions.The noise abatement shall be achieved by valve body and trim design and not by the use of silencers.

The valve trim shall be designed so as to achieve the noise abatement without any external means. However, if the noise level remains above 85 dBA, a cartridge/silencer/Lo-dB plate shall be provided externally to reduce the noise as recommended by ISA.Please accept.


50 Volume-V Part-B/Chapter-6 6.19.02(i) Temp. & humidity monitoring system in each control room, cubicle room, meeting room, training room, & conference room etc.

Temperature and humidity monitoring system is not envisaged to be provided in offsite control rooms.

Please accept

Confirmed.

51 Volume-V Chapter-14,Annexure-A

The following offsite systems are mentioned as PLC based:-Effluent Treatment,Intake water system.

We propose DCS based controls for these systems.Please accept. Agreed. However, any related issues will be discussed during contract finalization.

52 Volume-V Chapter-14,Annexure-A

Hydrogen Generation Plant Proprietary control system as per OEM recommendation shall be provided for Hydrogen Generation Plant.Please accept.


47 Volume- VI Ch-03Cl 3.2.3/ SH 3 OF 5

Proof checking of structural design of following structures shall be got from IITRoorkee/Reputed Govt. Institution by the Contractor at his own cost.

Bidder opines that Proof checking of structural design is not required. Bidder has the full ability to ensure the economical and safe design along with customer consultant.

However if required bidder may be allowed to get it done from any of the IITs/ Reputed Govt. Institution.Please confirm

Bidder to comply with stipulation of technical specification.

48 Volume- VI Ch-06 Cl 6.17.0 (1) / SH 7 OF 9 Route survey, Contour Plan, L-Section, Grid Pillars, bench markestablishment along the pipe line route and at the river bank and its

basin.

Owner is requested to furnish preliminary route survey contour plan along pipe line route.

Refer Addendum - 01.

49 Volume- VI Ch-06 Cl 6.17.0 (1) / SH 8 OF 9 &III/Ch-04/Cl 4.1/ SH 2 OF 3

Pipe line route about 6.00 km in length passes through/under Agricultural Land…………………….. scope of the Bidder. & The distance from raw water intakestructure to raw water reservoir shall be assumed as 9000 M.

Owner to please confirm the length of pipe for raw water intake (ambiguity between mechanical and civil technical specification i.e. 9km or 6 km).

Length of pipeline route is approx. 6 KM from Intake Complex to Plant Boundary.

50 Volume- VI Ch-06 Cl 6.17.0 (2) / SH 8 OF 9 Geotechnical investigation and hydrographic study at intake point as well as along pipe line route upto the plant site.

Owner requested to provide preliminary Geotechnical investigation and hydrographic study at intake point as well as along pipe line route upto the plant site if available.

Please refer WAPCOS Report. No investigation & study along pipe line route has been carried out. It lies in Bidder's scope only.

Civil

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51 Volume- VI Ch-06 Cl 6.17.0 (3) / SH 8 OF 9 Intake Well Complex shall be based on WAPCOS report (copy enclosed) Owner requested to provide WAPCOS report as same is not enclosed in the technical specification.

Refer Addendum - 01.

52 Volume- VI Ch-06 Cl 6.17.0 (4) / SH 8 OF 9 Approach Jetty - Approach of required……road of 3.75 m width. Bidder understand that there shall be no vehicular movement on the RCC jetty/bridge. Please confirm

Clause 6.17.00(4) has been deleted in line with WAPCOS Report.

53 Volume- VI Ch-02 Cl 2.6 (57) / SH 6 OF 11 Clearing and removing the buried items if any in the whole proposed plant area and the same is to be deposited with customer. Any infrastructure buried underground shall bedemented/relocated by bidder without any additional cost.

Please provide the details and drawings of existing/buried structures/services that are to be demented/relocated. In absence of the same, the estimation of its dismantling /relocation is not possible and hence in such scenario, the scope of referred clause should be excluded from bidder's scope.Please confirm


54 Volume- VI Ch-02 Cl 2.6 (62)(x) / SH 7 OF 11 Anti-termite and anti-weed treatment in all areas / buildings as per IS: 6313. Anti-termite and anti-weed treatment shall be given to all vulnerable areas/buildings.Please confirm.


55 Volume- VI Ch-06 Cl 6.16.00/ SH 7 OF 9 All masonry firewalls shall be minimum 345 thick and RCC firewall shall be minimum 200 mm thick.

It is understood with this clause that any one of them can be adopted in design stage. Please confirm.

Confirmed.

56 Volume- VI Ch-07 Cl 7.1/ SH 1 OF 1 Complete hopper including vertical and conical portion of bunker in mill building shall be provided with lining of at least 4 mm thick SS plate grade SS 316L .

Please note that the main purpose of providing liner in bunker is to bear impact load of coal falling from tripper and ensure smooth flow. Both of these purposes are served by providing liner on conical portion of the bunker only. Liner on vertical portion of the hopper shall not serve any significant purpose. In view of this, please confirm that liner on only conical portion of the bunker is acceptable. With respect to thickness and grade of the SS liner, please refer our query as below.


57 Volume- VI Ch-11 VI/Ch-11/Cl 11.3/ SH 6 OF 16 The grade of SS liner shall be SS316L. Tensile strength as well as hardness of SS 316L and SS 304 are comparable. Use of SS 316L is recommended in application requiring corrosion resistant material e.g. sea water application. Since, there is no such requirement; we propose to use SS304 as liner material in line with practice followed by bidder. Please confirm acceptance.Also liner thickness of 3.15mm in place of 4mm is envisaged by bidder as the same is sufficient to meet application requirement. Please confirm acceptance of 3.15mm in place of 4mm thick liner.


58 Volume- VI Ch-07 Cl 7.2/ SH 1 OF 1 Ordinary Portland Cement (OPC) Grade 43 shall be used for all structures. Usage of Portland pozzolana cement (PPC) may also be allowed in some areas. Please confirm.

Bidder to comply with stipulation of technical specification..

59 Volume- VI Ch-11 Cl 11.15.1/ SH 14 OF 16 The Raw Water Reservoir will have minimum live storage capacity as per mechanical requirement/WAPCOS report

Owner is requested to provide WAPCOS report for minimum live storage capacity detail.

RW Reservoir capacity : 5,30,000 cum in 2 compartments.

60 Volume- VI Ch-11 Cl 11.15.1/ SH 14 OF 16 Reservoir will be lined with H.D.P.E liners and protective plains cement concrete layer of grade M-15 and shall be provided in panel over a cement sand plaster in 1 : 6 to avoid damage of the liner.

Owner is requested to specify the minimum thickness for PCC panels. PCC Panel shall be minimum 100 mm thk.

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61 Volume- VI Ch-23 Cl 23.1/ SH 1 OF 3&Plot Plan (Drg no. 111-29-0200)

Para 4 - Type I roads shall consist of 10 metres ……………… plant complex circumferential road shall be Type I.

Para 9 - Road leading to main gate of power house building …………….shoulders and central divider will be 21.5m).

Owner is requested to confirm the road width from Main gate to main plant bldg. as there is ambiguity in para 4 & para 9. Also, as per plot plan, Type-1 road has been shown. Please Confirm.

Type 1 road shall be considered.

62 Volume- VI Ch-23 Cl 23.1/ SH 2 OF 3 Type I & II roads –250mm thick with 8mm TOR at 250mm c/c both ways at top and bottom(double layer) Sub – base : 2 layers of granular sub base plus 100mm thick PCC.

Owner is requested to provide the thickness of each layer of granular sub base. Thickness of granular base shall be as per design requirement.

63 Volume- VI Ch-23 Cl 23.1/ SH 1 OF 3 Type III roads shall be 3.75 m wide with 1.0m wide hard shoulders on one side. Type III roads shall be provided along the plant boundary for access for security and maintenance.

Bidder understands that plant boundary wall and plant boundary road are in owner’s scope. Please confirm.

All roads within boundary wall shall be in bidders scope.

64 Volume- VI Ch-23 VI/Ch-23/Cl 23.1/ SH 1 OF 3 Type III roads shall be 3.75 m wide with 1.0m wide hard shoulders on one side. Type III roads shall be provided along the plant boundary for access for security and maintenance.

As there is no description for approach roads, bidder understands that approach roads for buildings (other than Main power House bldg.) shall be of Type III. Please confirm.

Agreed. However, Plot Plan shall also be referred too.

65 Volume- VI Ch-2 Cl 2.8.1/ SH 8 OF 11&Tender drg no. 111-21-0600

Plant Leveling & Grading –….…Formation level of the entire plant area (except ash dyke area and raw reservoir area) has to be kept at 64.00 m level…… finished floor level of all buildings is to be kept +0.5 m above formation level (+64.00 m).

Please confirm the FGL of Main Plant area as there is ambiguity in Civil technical specification (RL +64.5m FFL) and Tender Drawing elevation marking (RL+133.5 FFL).

FFL of +64.5 M shall be considered.

66 Tender Drg Tender Drg No. 111-29-0200 (Plot Plan) Owner is requested to clarify the scope of road marked for future extension plant as no details are available in specification for future extension plant road.

All roads with Plant Boundary are in Bidders scope.

67 Volume- VI Ch-17 Cl 17.2 (v)/ SH 2 OF 20&VI/Ch-6/ Cl 6.08.00 / SH 3 of 9

….All handrails and ladder pipes(except at operating floors) shall be 50mm nominal bore MS pipes (medium class) ……

All handrails shall be of 32mm nominal bore MS pipes (medium class) as per IS:1161 galvanised using 750 gm/sq. m of zinc.

Bidder understands that clause Ch. 06, 6.08 page 3 of 9 shall prevail i.e. all handrails shall be of 32mm NB. Please confirm

Clause 6.08.00 for hand rails of 32 mm NB MS pipe to be followed.

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68 Volume- VI Ch-17 Ch-17/Cl 17.2 (v)/ SH 2 OF 20 All stairs and around all floor openings at operating floors, 1000mm high hand railing with 32 NB (polished) stainless steel pipe shall be provided.

All stairs and around all floor openings at operating floors, 1000mm high hand railing with 32 NB MS Galvanized pipes shall be provided. Please confirm.

Agreed.

69 Volume- VI Ch-17 Ch-17/Cl 17.7.4 (a)/ SH 8 OF 20 To suit the spacing of purlin, the length of sheet may vary between 1.50 to 2.00 m. The length of sheet shall be as per manufacturer standard.Please confirm.

Agreed.

70 Volume- VI Ch-21 Ch-21/Cl 21.2 (b)/ SH 1 OF 11 The paved area shall be sloped towards the drains with a minimum slope of 1 in 100. The maximum drainage travel extent shall be limited to 10 Meters.

For a drain slope of 1 in 1000 (min), paving slope shall be fixed in detailed design as per Storm water quantity. Further, the network & spacing of drain shall be decided in detailed engg.

Please confirm.


71 Volume- VI Ch-11 Cl 11.2 (b)/ SH 4 OF 16 Portion of the structural steel column projecting into the room shall be encased with brick masonry to shield it from fire hazards.

Bidder understands that the word “room” here refers to the common control room of the STG building. Please confirm

Agreed. Bidders understanding is correct.

72 Volume- VI Ch-12 & 13 Cl 12.3.7/ SH 3 OF 22&Ch-13/Cl 13.8.1/ SH 6 OF 11

Basic wind speed……..IS:875(Part-3):1987.K1 = 1.08K2=(Table 2 & Table 33,Category = 1,Class-B)

K2 shall be obtained from Table-2 of IS:875 (Part-3) considering terrain category I Class-C.

Please note that as per IS 875 PART(iii), the subject site lies in terrain category II.Terrain category I is taken as most severe category of wind force, generally taken at open sea areas, for the subject site this would lead to significant overestimation of wind forces.


73 Volume- VI Ch-12 Ch-12/Cl 12.5.1/SH 6 OF 22 “The liner shall be of corrosion resistant steel type “COR-TEN B” of minimum 10 mm thick.”…..

“The chimney Flue liner cladding shall be made of 2 mm THK Titanium (Grade 2 as per ASME-SB265) OR C-276 Alloy over 8 mm THK (Minimum) Mild steel base metal of Flue liner. Cladding shall be done to achive the requiality as per ASTM-B 898-11. Alternately contractor may provide Borosilicate Glass Block lining system.”

The above two statements are contradictory.

As for cladded steel options, bidder understands that the chimney Flue liner shall be made of 2 mm THK Titanium (Grade 2 as per ASME-SB265) OR C-276 Alloy over 8 mm THK (Minimum) Mild steel base metal of Flue liner. Cladding shall be done to achieve the quality as per ASTM-B 898-Please Confirm.

Agreed. Bidder's understanding is correct.

74 Volume- VI Ch-12 Cl 12.5.1/SH 6 OF 22 “The liner shall be of corrosion resistant steel type “COR-TEN B” of minimum 10 mm thick.”…..

“The chimney Flue liner cladding shall be made of 2 mm THK Titanium (Grade 2 as per ASME-SB265) OR C-276 Alloy over 8 mm THK (Minimum) Mild steel base metal of Flue liner. Cladding shall be done to achive the requiality as per ASTM-B 898-11. Alternately contractor may provide Borosilicate Glass Block lining system.”

Bidder understands that cladding can be done with explosion bonding or hot rolling or combination of both to achieve the required quality as per ASTM B 898-11.Please confirm.


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75 Volume- VI Ch-12 Cl 12.5.1/SH 6 OF 22 “The liner shall be of corrosion resistant steel type “COR-TEN B” of minimum 10 mm thick.”………….“The chimney Flue liner cladding shall be made of 2 mm THK Titanium (Grade 2 as per ASME-SB265) OR C-276 Alloy over 8 mm THK (Minimum) Mild steel base metal of Flue liner. Cladding shall be done to achive the requiality as per ASTM-B 898-11. Alternately contractor may provide Borosilicate Glass Block lining system.”

Alternatively, for borosilicate block lining system, in absence of any international codes or standards for borosilicate lining system, kindly furnish the complete specification for borosilicate block and adhesive, including material specification, warranty, procedure etc.

Further detailing shall be finalized during detail engineering.

76 Vol ume-VI Ch-3 Cl 3.15/SH 1 OF 5 The top most flue can shall be of stainless steel. Considering wet stack operations, and options give for flue liner, kindly furnish the complete specification for topmost flue can (minishell), for both cladded steel and borosilicate linning systems.


77 Vol ume-VI Ch-12 Cl 12.8/SH 9 OF 22 “…..where as other grid work shall support M.S. gratings as required….” Supporting Internal platforms and staircase with gratings will have a risk factor of small objects (nuts, bolts etc) falling through gratings of platforms and staircase. We recommend use of 6mm thick MS chequered plates instead. Please confirm.

Agreed.

78 Vol ume-VI Ch- 12 Cl 12.6/SH 7 OF 22 Insulation over chimney flue can Bidder understands that for borosilicate linning system, no insulation is required over flue cans. Kindly confirm. In such case kindly mention (with specification), if any primer/paint is required over external surface of chimney liner.


79 Vol ume-VI Ch-1 Cl 1.14/SH 8 OF11 Code IS 4998, 1992 Bidder understands that the subject chimney is to be designed with working stress method IS 4998 1992, rather than limit state method as per IS 4998 2015. Kindly confirm.


80 Vol ume-VI Ch-12 Cl 12.13/SH 12 OF 22 as per Cl. 12.13 “The staircase shall be supported by a structural steel framework supported from platform to platform independently of the wind shield.

Staircase provided directly on platform as per clause 12.13, would result in large platform girders, consequently large openings in windshield, which would be zone of weaknesses in the windshield. Further platforms are placed with sliding connections in windshield; placing staircase of around 40m on platform would result in stability issues under earthquake and other dynamic conditions.Therefore, the standard practice of staircase erected on brackets supported from windshield may be followed. Please Confirm.


81 Vol ume-VI Ch-12 Cl 12.23/SH 16 OF 22 "The laser scanning of chimney shell after every 70 m height and on completion should be performed”. "

Laser Scanning shall be performed for verticality check only. Pls confirm Agreed.

82 Vol ume-VI Ch-12 Cl12.16/SH 13 OF 22 “Reinforced concrete walls shall be provided at grade level around staircase… Unlike brick flue lined chimney with hoppers, this chimney is a completely compact unit, with no possibly of any ash nuisance at ground floor. Therefore, enclosure around staircase and lift for 10m, is uncalled, wasteful and not adopted anymore. Kindly confirm.

Confirmed.

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83 Vol ume-VI Ch-12 Cl 12.12/SH 12 OF 22 “…..Gas sampling ports fabricated from stainless steel with flanged ends ….” In light of wet stack operations, kindly confirm the specification of liner gas sampling ports.


84 Vol ume-VI Ch-2 Cl 12.3.7/SH 3 OF 22 “…..K1=1.08….” Kindly note that as per IS 875 (Part III) K1=1.07 for basic wind speed of 47m/sec. Kindly confirm.

Agreed.

85 Tender Drg No. 111-29-0200

(Plot Plan) S. No. 77 in Description Table “Time Office” Owner is requested to provide details of Time Office including finishing schedule, floor area, storeys etc. as shown in Plot plan.


86 Vol ume-VI Ch-2 Cl 2.6/sh 3 of 11 Point no. 22

87 Volume-VII TD Layouts – Plot Plan Raw water reservoir of required storage capacity (Minimum 6 days Storage) for running of 2x660MW unit.

88 Vol ume-VI Ch-11 Cl 11.15.00/sh 14 of 16 Raw water Reservoir Capacity – 5,30,000 Cum.

89 Vol ume-VI Ch-11 sh 14 of 16 Free board of 500mm minimum shall be maintained. The maximum level of Reservoir will be kept at level which will be at least 500 mm below the finished floor level of the plant or just at the plant formation level.

90 Vol ume-VI Ch-11 sh 15 of 16 Due to the length of the reservoir, waves may be set up by wind blowing over it. According to IS: 10635 a wave height of 1.0 m may be obtained hence the free board is kept as 1.0m. Hence the top of embankment is kept 500 mm above the finished floor level of Main Power House building.

91 Vol ume-VI Ch-2 Cl 2.8.1/ Formation level of the entire plant area (except ash dyke area and raw reservoir area) has to be kept at 64.00 m level.

Please furnish the extent of grading of the proposed site for scope clarity. Bidder to comply with stipulation of technical specification.

92 Vol ume-VI Ch-2 Cl 2.8.1/sh 3 of 11 Levelling and grading shall be carried out by selected cutting and filling of existing ground surface and earth. The cutting and filling requirements should balance each other to avoid earth from borrow pits as far as possible.

Bidder understands that FGL/FGLs of different blocks of the proposed site shall be finalized based on the site topography to balance the cutting and filling including terraced grading. Please confirm.


5,30,000 cum capacity is to be considered.

The referred clauses are contradictory. Please confirm the design storage capacity of Raw Water Reservoir.WAPCOS report is also required for detailed analysis and design.

Please confirm the top level of embankment and depth of free board of raw water reservoir.

Free board of 1500 mm shall be maintained.

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93 Vol ume-VI Ch-2 Cl 2.8.1/sh 3 of 11 A RCC retaining wall shall be provided at the junction of different grade levels with provision of stepped stair cases/ramps at different grade level locations for easy movement of persons, etc.

In case of different grade levels, necessary slope protection with dry stone pitching shall be provided in 1 V:2 H slope instead of providing RCC retaining wall. Please confirm


94 Vol ume-VI Ch-2 Cl 2.8.1/sh 9 of 11 However, 98% of standard proctor density is to be achieved for the Rail line corridor in the Marshalling Yard area of the plot area.

95 Vol ume-VI Ch-2 Cl 2.8.1/sh 11 of 11 Soil density check under railway track Acceptance Criteria i) Coarse grained soils which contains fines passing 75 micron IS Sieve, upto 5 percent should have the density Index (Relative Density) a minimum of 70% as obtained in accordance with IS:2720 (Part 14) – 1983. ii) For other soils, field dry density should not be less than maximum attainable dry density obtained in field compaction trial. However, in field compaction trial, the maximum attainable dry density should not be less than 98% of MDD values as obtained by Heavy compaction Test (IS:272 (part8) – 1983) in the laboratory.

96 Vol ume-VI Ch-3 Cl 3.2.1/sh 2 of 5 Inspection of site by BidderBidder shall inspect the site, examine and obtain all information required and satisfy himself regarding matters…….

Map indicating all crossings like high ways / railways / nala / river and bridges etc. may be collected from owner’s office.

Please furnish the Topographical Survey drawing showing spot levels and contours of the proposed site with co-ordinates in Auto Cad format for estimation of grading quantity.Please also furnish the Map indicating all crossings like high ways / railways /

nala / river and bridges etc.

Sl. No.- 02 of Addendum no.-01 to be referred for survey Map etc. Bidder to arrange at his own cost.

97 Vol ume-VI Ch-4 THERMAL POWER PROJECT BTPP Model (1).pdf The said drawing is showing spot levels/contours of some part of site and is incomplete drawing. Please furnish the Topographical Survey drawing showing spot levels and contours of the proposed site with co-ordinates in Auto Cad format for estimation of grading quantity.

Refer Addendum -01 to be referred for survey Map etc. Bidder to arrange at hiw own cost.

98 Vol ume-VI Ch-5 Cl 5.1/sh 1 of 4 GEOTECHNICAL INVESTIGATIONOwner of this project has carried out preliminary soil investigation work in power block area i.e. from power house to chimney. Few boreholes and standard cone penetration tests were performed. The soil report is attached at end of this chapter.

Both the clauses are contradictory. For Railway track area, filling shall be done with approved earth in layers of 250 mm compacted thickness so as to achieve relative density of 70% as per IS 2720 (Part 14) in case of cohesion less soil and 98% maximum dry density as per IS 2720 (Part 7) for cohesive soil. Please confirm

Preliminary soil investigation report is not available in tender document. Please furnish the same.

As per specification. (Railways requirement)

Addendum - 01.

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99 Vol ume-VI Ch-5 Cl 5.12/sh 4 of 4 For preliminary geotechnical investigation report refer Annexure – I

100 Vol ume-VI Ch-5 Cl 5.1/sh 1 of 4 As per the soil consultant’s report – Shallow foundation can be used at some locations, However, piling has to be provided for main plant building structures, ESP foundation, TG foundation, mill building foundation, mill foundation, conveyor gallery trestle (of height more than 20m) foundation, junction tower foundation, crusher house foundation, stacker reclaimer foundation & fly ash silo foundation including all other major structures. For conveyor gallery (of height less than or equel to 20m) foundation, type of foundation (pile / open foundation) shall be decided based on findings of final geotechnical report. In any case foundation shall not be placed on expensive soil.

Foundation system (open/pile) shall be decided based on approved Geotechnical Investigation Report during detailed engineering. Please confirm.

Agreed.

101 Vol ume-VI Ch-10 Cl 5.1/sh 12 of 36 Maximum allowable total settlement should be restricted to 25 mm for foundations of all plant structures like cooling towers, CW pump house, DM plant, crusher house, transfer house etc,.

Maximum allowable total settlement should be restricted to 40 mm for all other foundations.

Maximum allowable total settlement should be restricted to 25 mm for foundations of Power house, TG, Boiler, ESP, Fans, Mill bunker, Mills, Duct, Cooling tower, CW pump house, DM Plant, Crusher house and Transfer house only.Maximum allowable total settlement should be restricted to 40 mm for all other foundations.Maximum allowable total settlement for Chimney should be allowed to 75 mm. Please confirm.


102 Vol ume-VI Ch-16 Cl 16.2/sh 3 of 2 Geotechnical properties of AshAngle of internal friction (f) = 290

Angle of internal friction should be 29 deg. Please confirm. Agreed.

103 Vol ume-VI Ch-18 Cl 18.7/sh 5 of 10 m) The dynamic cone penetration tests shall be carried out for a depth of at least 2 meters from the termination depth. The number of such tests shall be as follows :a. One number dynamic cone penetration test for each pile group consisting of more than four piles.b. For TG and Chimney pile groups the number of dynamic cone penetration tests shall be one per cent of the total number of piles

Generally Dynamic Cone penetration test (DCPT) is conducted from ground level to access the resistance of soil with depth and is applicable only for shallow depth. DCPT is practically not possible to conduct below the termination depth of pile. Hence DCPT tests will not be conducted during piling. Please confirm.

Agreed.

104 Vol ume-VI Ch-23 Cl 23.1/sh 2 of 3 The drainage system shall be designed for precipitation intensity of minimum 80mm per hour.

105 Vol ume-VI Ch-14 Cl 14.13.2/sh 11 of 23 Drainage system shall be designed for maximum intensity of rainfall as 75 mm/hr and 60 % runoff coefficient.

80 mm/hr and run off coefficient shall be as per IS Code.

The referred clauses are contradictory. Please furnish the design rainfall intensity and run off co-efficient for paved and unpaved area.

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106 Vol ume-VI Ch-21 Cl 21.3/sh 1 of 11 The plant storm water drainage system shall take into account the topography of the plant area, area drainage patterns and intensity of rainfall etc. The drainage system shall be designed for a precipitation intensity equal to hourly rainfall for a return period of 1 in 50 years. However, storm frequency of 100 years return period shall be applied for Coal Storage area. These values shall be based on the recommendations of Indian metrological department (IMD).

Rainfal intensity shall be 80 mm/hour while run off co-efficient shall be as per IS Code.

107 Vol ume-VI Ch-17 Cl 17.6.1/sh 4 of 20 The area to be landscaped shall be clearly demarcated at site and got approved by the Engineer and the work shall be divided into following sub items.

Kindly specify the area to be landscaped. During detail engineering can be specified.

108 Vol ume-VI Ch-17 Cl 17.7.1/sh 6 of 20 ) Outside plaster on masonary wall:- no plastering is required on outside of masonary wall. Since outside surface of brick wall will be exposed, contractor to manufacture good shape bricks to suit the exposed brickwork. Silicone coating shall be provided on outside exposed face of brick wall.

Kindly specifiy the buildings that are to be provided with exposed brickwall and type of brick required for the same.

All buildings shall be provided with plastering on outside of masonry wall.

109 Vol ume-VI Ch-17 Cl 17.7.1/sh 6 of 20 ii) Inside plaster on masonary wall: 12 mm thick (1 cement : 3 sand) Bidder understand that the inside plaster whether it is rough face of fair face provided with 12mm thick plaster over the brick wall.

Bidder's understanding is correct.

110 Vol ume-VI Ch-17 Cl 17.7.1/sh 6 of 20 iii) Concrete ceiling: Plaster : 6 mm thick (1 cement : 3 sand) Bidder understand the where ever false ceiling are provided no ceiling plaster will be considered.

Bidder's understanding is correct.

111 Vol ume-VI Ch-17 Cl 17.7.5/sh 10 of 20 j) Glazed vitrified tiles :-Polished vitrified tiles shall be of 600 mm x 600 mm x 10 mm in sizeand shall be approved shade, brand and colour and shall be laid with CM 1:3.Operating floor, Control room area including control room ,computer room, control equipment room, SWAS Room and Conference room, senior executive room – The floor shall has vitrified tiles of size 2 feet X 2 feet applicable for industrial use.

Kindly clarify the floor finish for OPERATING FLOOR as per clause no.17.7.5, it is mention vitrified tile and as per clause no 17.7.15 Finishing Schedule (TABLE 1 : FINISHING SCHEDULE:-Operating Floor, Operating Area, laydown area) it is mention kota stone flooring.

Vitrified tiles shall be provided except laydown area.

112 Vol ume-VI Ch-17 Cl 17.7.8/sh 12 of 20 Hollow extruded section of minimum 3 mm wall thickness as manufactured by INDAL or equivalent shall be used for all aluminium doors, windows and ventilators.

Hollow extruded section For sliding window and ventilators of 3mm wall thickness are not available. Kindly suggest lower thickness for the same.

Bidder to comply with stipulation of technical specification

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113 Vol ume-VI Ch-17 Cl 17.7.9/sh 13 of 20 All the exposed structural steel i.e. wall, columns, bracings in STG control room and air-conditioning areas shall be provided with wooden wall panelling. The wall panel shall consist of teak wood batten grid of size 600x600 mm or as per site requirement. The size of batten shall be 2 inch x 1 inch. BWP grade plywood conforming to IS:710 shall be fixed on this grid. The Venner of approved quality and shade shall be fixed on the plywood as exterior finish with suitable adhesive. The entire work shall be carried out to the satisfaction of engineer.

kindly clarify the height, total thickness and final finish of the wall panelling. Bidder to design.

114 Vol ume-VI Ch-17 Cl 17.7.15/sh 19 of 20 ESP Control Room :-Floor Finish-"Granolithic floor with non metallic floor hardener in pump houses and Vitrified tiles in AC Areas"

In ESP Control room in the floor finish, it is mention pump houses floor, as per bidder understanding no such pump house are coming in this area. Kindly clarify the same.

No pumphouse in ESP Control room

115 Vol ume-VI Ch-2 Cl 2.8.4 (i)/sh 11 of 11 For the information of the bidder about the tentative scheme/scope,studies carried out by STPL through its consultants can be referred to as under:(a) Study carried out by IIT Roorkee(b) Detailed study carried out by M/s Rodic Consultant Private Limited.

Owner is requested to provide geographical details of Budha nalah alongwith study report of IIT Roorkee and M/s Rodic Consultant Pvt Ltd.Bidder understand Scope of work of Budha nallah is with Plant Boundary only. Please Clarify.

Refer Addendum - 01. IIT Roorkee Report and Rodic report is enclosed. However, both reports are for reference only.

116 Vol ume-VI Ch-2 2.6 (52) RCC storm water drainage system for the entire plant considering the eastern peripheral drain to be constructed on eastern side of the Plant area located between property fencing & boundary wall.

Owner is requested to provide all related details Bidder has to make his own assesment. All the said work covers necessary survey, planning & designing by the bidder.

117 Vol ume-VI Ch-2 2.6 (62 (xi)) All temporary roads and approach roads necessary for construction purpose shall be of WBM for a minimum width of 4m.

Bidder understands that approach roads mentioned here are temporary only. All final approach roads to buildings shall be of RCC Type-3 (except Power House Bldg.). Please confirm.


118 Vol ume-VI Ch-6 6.07.03 All stairs shall have maximum riser of 180mm and a minimum tread of 250mm. However, for Administration…………………………….angle shall be provided for edge protection of RCC stairs.

Common control room building of Main Power House shall have steel staircase. Kindly specify control room of which building shall have RCC stairs.


119 Vol ume-VI Ch-6 6.08.00 For RCC Stairs, handrails with 20mm………..mentioned otherwise. For RCC stairs outside the building (watch tower etc.), teakwood may get damaged due to rain etc. It is advisable to provide G.I. hadrails for outside RCC staircase. Please confirm.

Confirmed.

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120 Vol ume-VI Ch-6 6.12.00 ………...The precast covers shall be of minimum M25 grade and not more than 65 kg of weight.

For wider trenches (more than 1000mm), it may not be possible to maintain required weight. Please confirm.

Confirmed.

121 Vol ume-VI Ch-6 6.15.00 b. Fencing shall comprise 3.0m height PVC coated galvanized chain link fencing of minimum 8 gauge including PVC coating of mesh size 75 mm and galvanized concertina.

Confirmed.

122 Vol ume-VI Ch-6 6.15.00 c. Galvanized barbed of a height of 0.6m shall be provided above the chain link fence The diameter of steel wire for chain link fencing excluding PVC coating shall not be less than 12 gauges.

123 Vol ume-VI Ch-2 2.6 20. A raw water intake pump house & intake structure on river Ganga bank and pipe line (MS/GRP) from Intake to raw water reservoir in the Plant area

Intake structure will be on River Ganga

124 Vol ume-VI Ch-5 5.1 The source of raw water is Ganga Canal. The river water intake pumps shall be installed in the pump house of canal which shall supply raw water to in plant Raw Water Reservoir of 6 days storage approx. capacity 530,000 cum in two compartments.

WAPCOS Report to be followed.

125 Vol ume-VI Ch-11 11.15.3 During the canal closure, when no water is pumped in, particularly if the canal closure period is extended due to any reason.

126 Vol ume-VI Ch-8 8.2 …………...Equipment loads (which constitute all loads of equipment to be supported on the building frame) are not included in the imposed loads furnished below and shall be considered in addition to imposed loads…………..

After examing the given imposed loads in detail, bidder understands that equipment load has already been considered in given imposed load ( 5t/sqm for Heavy eqp storage, 5t/sqm for rotor removal area, 3t/sqm for equip laydown area etc.) and no extra equipment load to be added in Imposed load unless noted otherwise.Please confirm.

Confirmed.

127 Vol ume-VI Ch-9 9.2 Roof decking sheets shall be designed ………………….. and imposed load. Roof deck sheet shall be designed for RCC slab only (during green concrete stage). Load of finishes and imposed load shall be taken care by sRCC slab itself.Please confirm.

Confirmed.

127(a) Volume - IIIElectrical Works

Ch 33 : Emergency DieselGenerator SetSheet 5 of 31

33.04.07 The DG set will be installed indoor in DG Building. All equipments andaccessories shall be provided with tropical finish to prevent fungus growth.

DG Sets shall be installed in open and thus building is not required for this project. Please Confirm


Bidder understands that total height of fencing including concertina is 3m (2.4 + 0.6). Please confirm.Bidder understands that "Galvanised barbed" as mentioned in point c is same as galvanised concertina mentioned in point b. Please confirm.

Please clarify whether intake structure (pump house etc.) to be construted on River Ganga bank or in the canal of River Ganga as there is ambiguity in clauses of technical specification.

PAGE 16 OF 75




127(b) Volume-VI Ch-2 2.8.4 (i) Realignment of existing Buddha Nallah………………………….(ii) Project area drainage to cater rain water/storm water runoff…………..

1. Please clarify the scope of peripheral drain (outside plant boundary wall) as it is contradictory to exclusion Clause 2.6 (g) "Approach road(s) and associated works outside plant boundary". We understand same is excluded from Bidder Scope. pl. confirm.2. As per plot plan, boudary wall and fencing are crossing each other on east side (near rail track). As per Clause 2.8.4 (ii) (c), peripheral drain will run between fence and the project boundary wall which is contradictory. Please provide the route plan of eastern peripheral drain for clarity. 3. Owner is requested to furnish location of outfall structure and diverted route of budha nalah for planning of draingae.

Realignment of Budha Nallah & project area drainage are in bidder's scope. Both outfall & diverted Nallah route falls within plant boundary.

128 Volume II Ch-1 4.8 All the plant layouts shall be made in computerised 3D modeling system asdetailed in the Chapter-05, GTR, Volume II of Bidding Document. Contractorshall provide the completed plant documentation including integrated 3-D modelwith equipment drawings, data sheets, P&ID, BOQ, schematics, logic diagrams,test reports and quality plan, etc. attached to the respective equipment/systems in the 3D model, along with the design review software (networkready) which shall include interference check, walk-through animation,simulation, visual effect, photo realism etc. loaded on a server with Four (4)work stations (latest configuration for server & workstation) with one A-4 sizecoloured laser printer and one A-3 size coloured plotter. The software shallinclude facility for obtaining hard copies of all the drawings/documents onstandard plotter / printer. The requisite hardware and software shall be suppliedand commissioned. All soft wares provided shall necessarily include the cost forperpetual license(s) for use on all the machines and an Annual MaintenanceContract (AMC) which shall include software upgrades as & when released bythe software agency for a period of three (3) years after warranty/guaranteeperiod.

SJVNL is requested to waive off the requirement of 3D Model Review software and hardware considering the facts stated below:

One of our customer TANGEDCO waived off the requirement of 3D Model review software and hardware in 1X800MW North Chennai BTG package.

NTPC also has not asked for 3D Model review software and hardware for tenders.

In the following projects there has been no requirement of 3D Model Review software and hardware1) Singreni STG III(800MW EPC)2) Patratu (3X800MW EPC)3) Rosa (2X660MW EPC)4) Talcher STG III(2X660MW Main Plant Pkg)5) Rupsha 800MW CCPP6) Khurja STPP (2X660MW SG Pkg)

However, for model review, freeware software are available, in the use of which BIDDER can help SJVNL.

The Provision as per bidding specification shall prevail.

IPDS

PAGE 17 OF 75




129 Volume II Ch-5 8.3.4 (a) (iv) The completed plant documentation including integrated 3-D model withequipment drawings, data sheets, P&ID, BOQ, schematics, logicdiagrams, test reports and quality plan, etc. attached to the respectiveequipment/systems in the 3D model shall be furnished to Employer,along with the design review software (network ready) which shallinclude interference check, walk-through animation, simulation, visualeffect, photo realism etc. loaded on a server with four (4) work stations (latest configuration for server & workstation) with one A4 size coloredlaser printer and one A0 size colored plotter. The software shall includefacility for obtaining hard copies of all the drawings/documents onstandard plotter / printer.The requisite hardware and software shall be supplied andcommissioned by the Contractor at Employer's Project Office at Buxaror any other place notified by the Employer after award of work as permutually agreed schedule.All softwares provided shall necessarily include the cost for perpetuallicense(s) for use on all the machines and an Annual MaintenanceContract (AMC) which shall include software upgrades as & whenreleased by the software agency for a period of three (3) years afterwarranty/guarantee period.

SJVNL is requested to waive off the requirement of 3D Model Review software and hardware considering the facts stated below:

One of our customer TANGEDCO waived off the requirement of 3D Model review software and hardware in 1X800MW North Chennai BTG package.

NTPC also has not asked for 3D Model review software and hardware for tenders.

In the following projects there has been no requirement of 3D Model Review software and hardware1) Singreni STG III(800MW EPC)2) Patratu (3X800MW EPC)3) Rosa (2X660MW EPC)4) Talcher STG III(2X660MW Main Plant Pkg)5) Rupsha 800MW CCPP6) Khurja STPP (2X660MW SG Pkg)

However, for model review, freeware software are available, in the use of which BIDDER can help SJVNL.


130 Volume III CH-4 4.3 River Ganga carries huge silt load during monsoon months. The desilting arrangement shall be considered to reduce undesirable sediment particles in water fron entering the pipe line leading to the power project.

Following arrangemnts are considered w.r.t. desilting:1. Location of Jack well/ intake structure shall be decided so that silt entrapment shall be very less.2. No silt shall enter into pipeline as silt(if any) shall accumulate in pump sump i.e. well with space to accomodate silt (if any). Further, Silt evacuation shall be done manually during periodic maintenance from pump sump (jack well).

Will be finalized during detailed engineering.

Refer WAPCOS Report.

131 Volume III CH-4 4.6 External gland sealing arrangement/ external lubrication shall be provided for the Raw water Intake pumps with filtered water comprising of tank, filtration system, piping and valves etc to safe guarding the offered pumps.

For specified water quality, the water lubrication through Filteration system is not required for bearing lubrication of Raw water intake Pumps. Self pumped water is sufficient for bearing lubrication. Therefore supplementary system with fiteration system along with tank, piping valves etc. for bearing lubrication is not required.Please confirm.


132 Volume III CH-15 o) Sump Model tests & CFD Analysis and Flow tests We understand flow test is nothing but Physical sump model studies. Further since we are carrying sump model test, hence CFD analysis (i.e. mathematical cal. method) is redundant and thus not required.


MSE(Water System)

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133 Volume III CH-16 16.3 A minimum of 20 % margin shall be considered over and above the total required heat load to compute the design heat load and subsequently the design DMCW flow for the closed circuit.

134 Volume III CH-16 16.7.5.4 A minimum of 20 % margin over and above the total required heat load as obtained above shall be taken intoaccount by the Bidder to work out the design heat load rejected byDMCW system and to be picked up by ACW system for the same.

135 Volume III CH-16 16.3 In computing the design heat load and design DMCW flow in individual DMCW system Bidder shall ensure that the average temperature rise of DMCW is limited to 5.5 deg.C under all circumstances.

136 Volume III CH-16 Datasheet of PHE Inlet – Bidder to work out.However DMCW systemtemperature rise not toexceed 5.5 deg. C.

137 Volume III CH-16 Datasheet of PHE Outlet – 36 Deg C Outlet temperature of 36 °c for DMCW system is in-appropriate as ACW design temperature shall be 36 °C & corresponding DMCW design cold water temperature shall be 38/39 °c corresponding to TTD of 2°C/3°C.

Please confirm.


138 Volume III CH-15 15.7.7 (iii) Water required for cooling of pump-motor guide and thrust bearing shallbe taken from main pump discharge through duplex filter.

For specified water quality, there is no requirement of duplex filter for this purpose.Please confirm the requirement.

Agreed.

139 Volume VII-TD Drg no-111-12-3100 - Clarified water to HVAC make up, APH/ ESP wash, AHP seal, CHP Dust suppression are fed from respective dedicated pumps for respective purposes.

140 Volume VII-TD Drg no-111-12-3400 - Clarified water to HVAC make up, APH/ ESP wash, AHP seal, CHP Dust suppression are fed from Service water pumps.

141 Volume III CH-7 7.2.1 Bidder to provide Servce Water ffor HVAC makeup as and where required, Seal Water for AHP, Dust Supperation in CHP Area & other area for PlantService.

142 Volume VII-TD Drg no-111-12-3100 - Configuration of Service water pumps is 1 working + 1 stand by i.e total 2 no of service water pumps

143 Volume VII-TD Drg no-111-12-3400 - Configuration of Service water pumps is 2 working + 1 stand by i.e total 3 no of service water pumps


Agreed.

Confirmed.This is a contradiction in specification. We propose to consider configuration of Service water pumps as 2 working + 1 stand by i.e total 3 no of service water pumps.

20 % margin on heat load for DMCW/ACW system over and above following margin in PHE (as per specification) : [1 ) fouling factor 0.8 x 10-4 m2 hr. °C / kcal (2) 5% increase in no. Of Plates]is neither required nor an optimized engineering practice as same will unnecessarily increase the sizes of the equipment, pipes, fittings etc. Further please note that PHE effectiveness reduces with additional unwanted margins dure to reduction in turbulance.In view of above it is proposed not to impose 20% margin on Heat load in DMCW / ACW system.Please confirm.

Subject tender is EPC tender wherein complete DMCW & CW/ACW system is in bidder scope. Therefore putting a limit on overall temperature rise viz. 5.5 °C is neither required nor an optimized engineering practice as same will unnecessarily increase the size of the equipment, piping, fittings etc. In view of this, it is proposed not to impose any temperature rise limit in DMCW / ACW system.Please confirm.

We have considered separate pumps for HVAC make up, APH/ ESP wash, AHP seal, CHP Dust suppression in line with drg no. 111-12-3100.


PAGE 19 OF 75




144 Volume VII-TD Drg no-111-12-3100 - Configuration of Potable water pumps is 1 working + 1 stand by i.e total 2 no of service water pumps

145 Volume VII-TD Drg no-111-12-3401 - Configuration of Potable water pumps is 2 working + 1 stand by i.e total 3 no of service water pumps

145(a) Volume IIGeneral & Schedule

Ch11 : QAP(Mechanical)Sheet 51 of 94

Clause 16.0 DEBRIS FILTER Being River Water Application, Debris Filter shall not be required. Please confirm.

Confirmed.

145(b) VOLUME III – MECHANICAL WORKS(Book 1 of 2)

Chapter 06, Colume 3, 'Chapter 06: Clarified Water System.

Colume 3, Chapter 06: Clarified Water System. Tender Specification of Clarified Water is missing in Vol-III. Same may please be provided to Bidder.

Clarified water system is included in water treatment chapter.

146 Technical Specification & Tender Drawings (MECHANICAL) We have gone through technical specification and tender drawings in details and seen that excessive instrumentation & motorized valves have been asked which are neither required for system O&M nor for any control. This shall increase the Project cost as well as maintenance work unnecessarily during actual plant operation. As per BIDDER’s long experience, we do not recommend such excessive instrumentation & motorized valves for safe & trouble free operation of the Plant. Suitable clarifications are raised below for your review and consideration.


147 Drain and vents, manual /motorized valves, NRVs, IBVs, etc. as indicated in the tender PID.

We understand that drain & vent valves, IBV, motorization of valves, etc. as shown in the Tender drawings are indicative only. The finalization of these items shall be as per the system O&M, control & layout requirement.

Confirmed.

148 Refer NOTES:Quantities & type of Instruments/ analyzers shall be finalized by the owner during detailed engineering as per process & redundancy requirements as stipulated in the technical specification.

Instrumentation shall be provided as per system operational & control requirement as per BIDDER latest engineering practice being followed in supercritical plants.


149 Refer zone F-11, G-11 & zone F-9, G-9-there is duplication of instruments PT & PG for pressure measurement at supereheater outlet header.

PT & PG downstream of ERV shall not be provided since there is duplication of pressure measuring instruments at this location.


150 Refer zone G-10 & zone B-10, TE's for metal temperature measurement have been indicated.

No TE will be required in Y piece due to lower thickness in view of F91/F92 material, hence same shall not be provided.


Confirmed.

General

Vol.-VII, Tender drawings mechanical.

Vol.-VII, Tender drawings mechanical.

Flow diagram of MS, CRH & HRH. DWG. No. 111-11 -0200


MSE(Power Cycle)

This is a contradiction in specification. We propose to consider configuration of Potable water pumps as 1 working + 1 stand by i.e total 2 no of potable water pumps.

PAGE 20 OF 75




151 Refer zone H-5 & zone G-4, F-4 there is duplication of PG & TG at these zones. PG & TG as indicated at zones G-4 & F-4 shall not be provided, as PG & TG provided at zone H-5 shall serve the purpose.


152 Refer zone E-11, C-12 & zone E-9, C-9-there is duplication of instruments PT & PG for pressure measurement at Reheater outlet header.

PT & PG downstream of ERV shall not be provided since there is duplication of pressure measuring instruments at this location.


153 Refer zone D-11 & D-8,DPTs have been indicated. DPTs at these zones across reheater are not required and shall not be provided. Will be finalized during detailed engineering.

154 Refer zone B-9, TEs & PTs have been indicated. Adequate instruments have been provided at boiler end and at turbine end, hence TE's & PT's at zone B-9 shall not be provided.


155 Refer zone E-6,two outlets from HP turbine for CRH line have been indicated. In BIDDER Turbine, there is only one outlet for CRH line Agreed.

156 Refer zone E-10 & C-10,PT & TE have been indicated. PT & TE at these zones are not required since same have been already indicated at Zone-H4 in Flow Diagram of MS, CRH & HRH system from where tap-off for HP bypass is taken.


157 Refer zone E-10 & C-10,drip leg is indicated. As per BIDDER layout, there is no low point at the zone E-10 & C-10 hence drip legs are not required. Drain points / drip legs shall be provided as per actual layout adopted during detail engineering.


158 Refer zone G2, TG is indicated. TG indicated is not required as same is already indicated in the flow diagram of Feed Water System from where the spray tap -off is taken.


159 Refer zone G3,F4 & D4,Stop valves are indicated in common spray header as well as in individual spray lines to HP bypass valves.

Stop valve indicated in common spray header at zone G3 shall only be provided as per BIDDER standard practice.


160 Refer zone F4 & D4,motorised isolation valve, motorised bypass valve & isolation valve across spray control valve are indicated.

No motorised isolation valve, motorised bypass valve & isolation valve across spray control valve shall be provided as manual operation is not recommended. Bidder does not recommend these valves for ensuring safety of the system.


161 Refer Zone A-10, Note-4, LP Bypass valve downstream pipe upto the condenser nozzle- design temperature for the complete line shall be selected based on spray failure condition in LP bypass valve, selection of design temp. shall be derived from equivalent enthalpy method between u/s & d/s points of Lp bypass valve at spray failure condition.

As per BIDDER arrangement, spray is integral to LPBP valve. In case of spray failure condition, LPBP valve shall also close. Hence, the d/s piping design temperature shall be selected based on maximum sustained continous opertaion. Alloy steel material shall be provided d/s LPBP valve's piping.




Flow diagram of HP & LP Bypass System DWG. No. 111-11-0301









PAGE 21 OF 75




162 Alloy steel piping shown in HPBP d/s & CRH line , zone E-5. Alloy steel pipe shall be provided upto & including 1st bend d/s HPBP valve. Alloy steel pipe shall be provided in CRH line from HPT exhaust upto CRHNRV.


163 Motorized valves u/s & d/s deaerator pegging control valves are indicated in the tender drawing

Motorized valves u/s & d/s deaerator pegging control valves (CRH & Aux. Steam) are not recommended for safety of BFP’s Booster Pump and hence shall not be provided.


164 CRH & Aux. Steam source for deaerator is indicated in the tender drawing. As auxiliary steam is also coming from CRH line, another alternate source from CRH is not required for Deaerator and shall not be provided. System shall be designed for all operating conditions.


165 Motorized valve at aux. steam line is indicated in the tender drawing. Motorized valve at aux. steam line is not required since these valves are always in open condition.


166 Extraction to HPH & LPH NRVs Extraction to HPHs & LPHs, the number & type of extraction NRVs shall be inline with Turbine Manufcaturer's recommendation.


167 Vol.-III, Mechanical Ch.2 : Steam Turbineand its AuxiliariesSection-1: Scope of WorksSheet 5 of 12

xiii) In addition one atmospheric flash tank will also be provided to accept the drains from feed water heater safety valves.

Will be decided during detailed engineering.

168 Vol.-III, Mechanical Ch2: Steam Turbine and itsAuxiliariesSection-2: Design BasisSheet 51 of 70

6.2 (D) The alternative scheme/ arrangement for connection of drains to different flash tanks as per standard proven practice of OEM shall be acceptable.


169 Refer zone C11,TE, TG, PT and PG on common inlet header on steam extraction line from IPT to BFPT-A & B are indicated.

Referred instruments are already provided at IPT extraction line (ZONE E-6 DWG NO. 111-11-0400) and hence duplication of these instruments are not required.


170 Refer zone B10, DPT , DPG and QCNRVs at the common inlet header on steam extraction line from IPT to BFPT-A & B are indicated.

This complete arrangement is provided at IPT extraction common line for deaerator pegging and BFPT supply as per our Turbine Manufacturer's recommendation.


171 Refer zone H11, PT, PG & TG on start-up source from auxiliary steam system to BFPT-A & B are indicated.

Referred instruments are already shown at zone D-7 of Auxiliary Steam System (refer-Flow Diagram of Auxiliary Steam System).


172 Refer zone G-10 & G-6, motorised valve is indicated. Motorised valves at this location are not required since these valves are always in open condition.



Flow diagram of Extraction Steam System DWG. No. 111-11-0400



Safety relief valve’s discharge piping for HPHs & LPHs shall be led to Flash Pipe,

Flow diagram of Extraction Steam for BFP turbine DWG. No. 111-11-0401





PAGE 22 OF 75




173 Refer zone H-3, alternate source from CRH line. As auxiliary steam is also coming from CRH line, another alternate from CRH source is not required for BFPT and shall not be provided. System shall be designed for all operating conditions.


174 Refer Zones F-10 & F-8 ; F-6 & F-5,separate flow nozzles are indicated for Aux Steam/CRH line & IPT extraction line to BFPT-A & BFPT-B.

The arrangement, viz. piping, valves etc., shown is different from bidder's design. Single admission BFPT, with single set of stop & control valve for admission to each BFPT, only at the inlet of BFPT, shall be provided as per bidder's design. However, bidder confirms to meet all the intended functional requirements with the bidder's design.


175 Refer zone G-10,F-10; G-8, F-8; G-6,F-6 TE's are indicated in the emergency drain line of HP heaters to flash tanks.

TE's are not required in the emergency drain lines of respective HP heaters to flash tanks and hence same shall not be provided.


176 Refer zone F-2,E-3,C-4 TE & TG are indicated in the emergency drain line of LP heaters to flash tanks.

TE & TG are not required in the emergency drain lines of respective LP heaters to flash tanks and hence same shall not be provided.


177 Refer zone G-10, E-10;H-9, F-9 , temperature measurement (TE's, TG's) are indicated at the upstream as well as downstream of control station in normal drain lines of HPH-7A to HPH-6A & HPH-7B to HPH-7B. This is typical comment for normal drain lines of all HP and LP heaters.

Temperature measurement -TE's shall be provided only at upstream of respective control stations in normal drain lines of HPH-7A/7B, HPH-6A/6B, HPH-5A/5B & LPH-4, LPH-3, LPH-2 & LPH-1 . TE/TG downstream of control station is not required as the same is not used for any control function.


178 Refer Zone H-3,indicated Venting arrangement. The type of Valves, arrangement and number of Valves for Deaerator's Venting arrangement shall be inline with the Notes S.No.2 & as per Deaerator manufacturer's recommendation.


179 Refer zone C-11 & C-8, TE's are indicated in the HP & LP heaters drip connection to respective flash tanks.

TE's are not required since these valves are of class-V leakage class and also these valves are not operated frequently.


180 Refer zone- D-4, motorised valve is indicated in the service water line to atmospheric flash tank.

Orifice and manual regulating valve shall be provided in this line as per BIDDER standard practice.


181 Refer zone- G-7, motor operated bypass valve is indicated in the spray water from CEP discharge line to flash tank.

As flash tank is designed for spray failure condition, manual regulating bypass valve shall be provided instead of motor operated bypass valve in the spray water from CEP discharge line to flash tank.




Flow diagram of Heater Vent and Drains DWG. No. 111-11-0500





Flow diagram of Steam Drain System DWG. No. 111-11-0501


PAGE 23 OF 75




182 Refer zone C-11 & D-8, TE's are indicated in the drain arrangement & atmospheric flash tank resp.

No TE shall be provided d/s MOV in drain lines. As atmospheric flash tank is designed suitably for all operating conditions TE is not required here. However, local TG shall be provided on atmospheric flash tank.


183 Refer zone C-7, feed water heater safety valve discharge is led to atmospheric flash tank. All feed water heaters safety relief valves discharge pipe shall be led to the atmosphere through the Flash Pipe for aesthetic piping layout.


184 Refer zone E-11,Control station and flow element for the normal and emergency make up is indicated separately. Each control valve is bypassed through the motor operated valve. A motor operated valve is provided upstream of the makeup control valve.

Common control station with one flow element shall be provided for the condenser normal & emergency make up. Normal and emergency make up control valve shall be bypassed with a single motorized inching type valve and each control valve shall be isolated by a manual valve at the upstream.


185 Refer zone B-9,C-9,D-9, Motor operated valves are indicated in the individual CEP suction piping.

Manual gate valve with Locked Open (LO) facility shall be provided in the individual CEP suction line for SAFETY aspect.


186 Refer zone B-8,C-8,D-8, TEs are indicated in the individual CEP suction piping. TEs as indicated in the individual CEP suction piping are not required since TE is provided in common line zone D-9.


187 Refer zone B-7,C-7,D-7,flow transmitter in individual condensate discharge line are indicated.

Flow element at each CEP discharge shall be located d/s discharge motorized valve for better piping layout and smooth CEP operation.


188 Refer zone E-7,individual CEP recirculation lines have been indicated. At zone C-4, common CEP recirculation is indicated.


189 Volume - IIIMechanical Works

Ch2: Steam Turbine and itsAuxiliariesSection-2: Design BasisSheet 38 of 70

xii) Individual recirculation line for each CEP shall be provided. Will be decided during detailed engineering.

190 Refer zone E-7, motorized isolation valve at upstream of CEP minimum recirculation control valve and pneumatic control valve at bypass are shown .

Motorized isolation valve at upstream of CEP minimum recirculation control valve is not recommended and manual valve shall be provided. Regulating motor operated valve shall be provided in the bypass line instead of control valve.


191 Refer zone D-4, motorized isolation valve at upstream of Excess return control valve and upstream & downstream isolation valves in the bypass line to excess return control valve are indicated.

Manual valve at upstream of excess return control valve and its bypass line shall be provided, instead of motorized valves.


192 Refer zone F-5, motorized isolation valve at downstream of each deaerator level control valves and motorized isolation valve at upstream & downstream of the bypass line to deaerator level control station are indciated.




Flow diagram of Condensate System DWG. No. 111-11-0600



Flow diagram of Condensate System DWG. No. 111-11-0600 There is contradiction in tender dwg. and specification clause 1.6(2) & (3).

Control station arrangememt shall be inline with Specification clauses 1.6(2) & (3).


Flow diagram of Condensate System DWG. No. 111-11-0600 Individual minimum recirculation lines for each CEP is not required from system operation point of view. Common recirculation line alone is sufficient to fulfill the technical requirement. We propose to provide the common recirculation line after GSC (zone C-4).



PAGE 24 OF 75





Ch.2 : Steam Turbineand its AuxiliariesSection-1: Scope of WorksSheet 7 of 12

1.6 (2) & (3) 2) One motor operated gate valve on upstream and one manual operated gate valve on downstream of each condensate control valve.3) One motor operated inching valve in bypass line of above condensate control station.


194 Refer zone H-9,H-7, H-5, PTs are indicated. No PT is required d/s LPHs as the pressure indication in the control room will not serve any purpose.


195 Refer zone H-7, H-5 & F-7 Motorised valves are provided with integral motorized bypass valves after each of the LPHs.

Integral motorized bypass valves after the LPHs are not required for system O&M and shall not be provided.


196 Refer zone E-8, PT,PG,TG,TE are provided. These instruments are not at all required as drain cooler is part of LPH-1. Will be decided during detailed engineering.

197 Refer zone E-4,motor operated valves are indicated for oxygen, hydrazine and ammonia dosing.

Solenoid valve for oxygen dosing shall be provided. Manual valves for hydrazine and ammonia dosing shall be provided as valves will remain open always during normal operation of Unit.



Ch2: Steam Turbine and itsAuxiliariesSection-2: Design Basis

3.1(viii) Maximum oxygen content of condensate leaving the condenser shall be 0.015 CC per litre over the entire load range.

As oxygen dosing is required for all supercritical plants, oxygen content at Condenser & Deaerator is not applicable.


199 Zone F-2, Boiler filling line & deaerator initial filling are indicated. As dedicated Boiler Fill Pump (2x100%) are provided, additional filling line from CEP discharge for Boiler and Deaertaor initial filling is not required and shall not be provided.


200 Zone B-7, C-7, D-7, motorised IBV's are shown. Bypass valve of main discharge motorized valve at each CEP discharge shall be manual for safe operation of CEP.


201 Zone G-9, in D/A drain line motorised valve alonwith manual valve are indicated. D/A drain line shall be provided with a single manual valve for draining D/A to flash tank


202 Refer zone C-10 , D-10 & E-9, motor operated gate valve with LSC/LSO are indicated in the individual BFP suction line.

Manual gate valve with Locked Open(LO) facility shall be provided in the individual feed water suction line for SAFETY aspect.


203 Refer zone C-7 , D-7 & E-7, motor opearated valves with integral bypass valves are indicated.

No MOV is required as this valve (to reheater spray) will remain in open condition always .


204 Spray tap of for the bypass system is indicated after HPH train in the tender PID. Spray tap of for bypass system shall be taken before the HPH train. The provision as per bidding specification shall prevail.

(3).




Flow diagram of Feed water System DWG. No. 111-11-0700







PAGE 25 OF 75




205 Refer zone, E-8,C-8 & B-8, TE's are indicated. These TE's are not required as per pump manuafcture's control logic and hence shall not be provided.


206 Zone H-9, DPT across Feed Control Station There is no requirement of DPTs across FCV for changeover to MOV from FCV as per our proven System design for numerous projects.


207 Refer zone C-7, motor operated valve with motor operated IBV is indicated downstream of feed control valve.

At the downstream of the 30% FCV, manual gate valve shall be provided. The provision as per bidding specification shall prevail.

208 Refer zone D-4, D6; E-4, E-6 & F-4, F-6, PTs are indicated. No PT is required u/s & d/s HPHs as the pressure indication in the control room will not serve any purpose.


209 Refer F-5, F6 IBV is indicated after each HPH train along with the two strings of 50% motorized valve bypass .




5.1 iii) In addition, 2x50%capacity spring loaded relief valves shall be provided in the bypass arrangement of HP Heaters with each spring loaded valve capable of passing feed flow equal to 50% BMCR capacity.


211 IBVs across MOVS downstream of HPHs in single string HP HEATER arrangement. Downstream of HP heaters, there is no requirement of any IBVs across MOVs. The provision as per bidding specification shall prevail.

212 Refer zone G-2, Spray tap off for the HP bypass system is indicated after HPH train & MOV is indicated.

Spray tap off for the HP bypass station shall be taken before the HPH train from Boiler feed pumps discharge as per clause 1.20 (e). Also, MOV is not required at tap-off.


213 Refer zone G-12 & F-11, 1. Safety relief valve is indicated in the BFP recirculation lines. The safety valve shall not be provided in the BFP recirculation line as the pipeline shall be designed accordingly.

Confirmed.


Ch 26 : Power Cycle Piping, Valves,Fittings & Thermal InsulationSheet 3 of 26

26.1.3 © The design pressure for BFP discharge piping up to and including downstream valve at feed regulating station (FRS) shall be selected……………………………………… Discharge pressure corresponding to turbine driven BFP trip speed at shut off head flow condition…………………. However bidder may consider 20% higher stress as per the provision of ASME B 31.1 (for the piping up to downstream valve at feed regulating station only) for which the requirement of special provision asper stipulation of clause no. 520 of IBR shall be met as a must by the bidder. …….. based on design pressure calculated as per above.

Please clarify which ‘special provision’ shall be provided for BFP to avail 20% higher stress.









Flow diagram of Feed water System DWG. No. 111-11-0700 IBV after the HPH train is not required and hence not envisaged. Two strings of 50% motorized valve bypass line are not required and not envisaged in view of the 2x 50% capacity SLBV line already provided.

PAGE 26 OF 75




215 Refer zone, F-6 & G-6, CST of capacity 1000M3 indicated. Agreed.

216 Vol.-III, Mechanical Ch.2 : Steam Turbineand its AuxiliariesSection-1: Scope of WorksSheet 6 of 12

1.2.2.3 Condensate storage tank (capacity of the CST shall be 2x1000 m3) Agreed.

217 Refer zone F-5 & H-5, four hotwell make up pumps, two each for unit 1 & unit 2 are indicated.

3 pumps (common for 2 units) are adequate for efficient system operation. The provision as per bidding specification shall prevail.

218 Refer zone C-11 & C-9,upstream & downstream of each emergency hotwell make up pump, MOVs are indicated.

No MOV at upstream & downstream of each emergency hotwell make up pump is required.


219 Spray to HCPRDS & LCPRDS is indicated from BFP discharge/interstage or CEP. Spray will come from CEP discharge for combined HCPRDS. Agreed.

220 Refer zone G-2, motor operated isolation valve upstream of spray control valve alongwith pneumatic bypass valve with its upstream motor operated isolation valve & downstream isolation valve are indicated in spray control station to HCPRDS.


221 Vol.-III, Mechanical Ch 1: SG & AuxiliariesSection 1 : ScopeSheet 7 of 47

1.1.10 Spray control station comprising of one number each of pressure and temperature control valve, electro hydraulically/electropneumatically operated, on the desuperheating spray water line along with an identical 100% capacity bypass arrangement


222 Zone H1, TE, TG, PT, PG are indicated. These instruements are not required as they are already provided at CEP discharge line from where spray line is tap-off.


223 Zone H-1, block valve in the common spray header from CEP discharge Will be decided during detailed engineering.


1.10.3. One pneumatically operated quick acting block valve (with solenoids) upstream of the Desuperheating spray water control station in the common line feeding to the high capacity desuperheating spray water control stations.


225 Zone F-10, motorised isolation valve upstream & downstream of bypass valve to LCPRDS is indicated.

We do not recommend isolation valves (u/s & d/s) for motorized inching bypass valve.


Flow diagram of Auxiliary Steam System DWG. No. 111-11-0300


Flow diagram of Auxiliary Steam System DWG. No. 111-11-0300 One number of control valve pneumatically operated on the desuperheating spray water line along with a motorized inching type bypass valve shall be provided.

No isolation valve shall be envisaged for the motorized inching type bypass valve at the upstream & downstream side.


Flow diagram of Auxiliary Steam System DWG. No. 111-11-0300 Block valve at the common line is not required being low pressure application from CEP discharge

Flow diagram of HOT WELL MAKEUP & BOILER FILL SYSTEM System DWG. No. 111-12-3308

CST capacity as mentioned in the specification is 2*1000 m3 which is quite much higher than the requirement. The makeup / condensate requirement being 1.0 % only in supercritical jobs. The capacity of 1X600 m3 is sufficient to cater the make-up requirement for single unit. Hence we propose the nominal capacity of each CST as 600 m3.



PAGE 27 OF 75




226 Zone F-10 & G-10 , 2 TE's are indicated . One TE shall be provided for temp. compensation. The provision as per bidding specification shall prevail.

227 Zone C-8, TE, TG, PT, PG are indicated. These instruments are not required. The provision as per bidding specification shall prevail.


1.1.10.1 (ii) HCPRDS with separate desuperheater The provision as per bidding specification shall prevail.

229 Zone G-10, Combined HCPRDS is shown in tender drawing The provision as per bidding specification shall prevail.


1.10.10 Suitable Pressure Reducing Station for supply of steam to Air ConditioningPlant (Vapour Absorption system); (if applicable)

The auxiliary steam shall be provided at the desired parameters of AC plant requirement with the proven control station arrangement and practices being followed for smooth and trouble free operation.

Agreed

231 Volume VInstrumentation & Control Works

Part B/Ch 11: ControlValves With ActuatorsSheet | 9 of 9

11.09.01 ii (2) Trim of severe/critical service valve shall be of multi stage & multi path design with sufficient no. of discrete pressure drop stage to eliminate the chance of erosion, cavitations, noise, vibration throughout the control range of valve.

The HCPRV will be provided with multistage with sufficient no. of discrete pressure drop stages to eliminate any chance of erosion, cavitation, noise, vibration throughout the control range of valve.Multipath trim will not be envisaged.For LCPRV and spray control valve,these requirements (clause 11.09.01) are not applicable .




11.09.01 ii (4) Actuators should be pneumatic double acting piston type. Pneumatic double acting piston type actuator will be provided only for HCPRV (from MS line).For rest of the valve diaphragm type actuators will be provided. The same philospohy is being followed for all earlier executed projects and same has been working satisfactorily.




11.04.01 Material of the HC PRV valve internals should be as under or better:-Guide : Inconel 718Plug/stem : Inconel 718Seat ring : SS 316 stellited

Material of the valve internals should be as under :For HVPRV :Guide : SS316/1.4922 hardened (X20CrMOV12-1)Plug/Stem : SS316/1.4922 hardened (X20CrMOV12-1)Seat ring : SS 316 stellited.The same philosophy is being followed for all earlier executed projects and same has been working satisfactorily.




11.04.00 Service : Low Flashing/ cavitations services

Body material : Cast Alloy Steel ASTM A217 Gr. WC6

The design temp of spray control valve from CEP discharge is 60 deg C. Hence, WC6 is not required & body material shall be WCB for APRDS spray control valves.




Combined HCPRDS with integral desuperheater shall be provided as shown in tender drawing.


PAGE 28 OF 75






11.09.01 (3) The valve shall have minimum class-V leakage for all steam applications including RH/SH, APRDS,

We understand that Class V leakage needs to be provided only for the critical application.HCPRV shall be provided with Class V leakage. CRH PRV and spray control valves shall be provided with Class IV leakage.


236 Volume III :Mechanical Works


26.1 (i) Steam traps shall be of inverted bucket / thermo static type with integral or separate Y type strainers.

Thermodynamic steam trap with integral strainer shall be provided in steam drain lines as per BIDDER standard practice.

However, inverted bucket/ float type trap with external strainer shall be offered for continuous drain services (like GSC drain).




viii) (a)(b) CEP sizingCombined flow of 2 x 50 % CEP to be based on 10% margin over highest condensate flow envisaged during unit operation (excluding HP/LP bypass operation).

Corresponding to above considering 10% margin over deaerator pressure

CEP combined Flow shall be based on 10% margin over VWO 1% make up for the efficient and optimized pump selection. However, CEP shall be sized to cater all operating conditions.

To calculate the total dynamic head of the pump, frictional drop shall be calculated as per actual flow from the system as per corresponding HBDs.




26.1.3 (d) The design pressure of boiler feed discharge piping at downstream of block valve on FRS shall be 105% of pressure corresponding to emergency point of BFP operation.

Feed Control Station shall be located upstream of HP Heaters as per the tender drawing for feed water system. Hence, tube side design pressure for HP heaters shall be the maximum pressure expected from boiler side as per provision permitted by IBR.



Ch 10 : Hotwell Makeup &Boiler/Deaerator Fill SystemSheet 3 of 6

10.3.3 Bidder shall also conduct water hammer analysis of the piping system in different transient conditions such as closure of valves, tripping of pumps.Bidder shall also consider such transient pressure surges in designing of the piping systems. The procedure and results of water hammer analysis shall be furnished to purchaser for his information and approval.

Please be informed that the water hammer analysis, transient pressure surge analysis is not required for the DM water make up lines from CST to condenser in view of low flow, low pressure & low temperature applications.



Ch 27 : Low Pressure Piping,Valves & SpecialitiesSheet 2 of 35

27.1.3 (b) Water Velocity in m/sec

Pump discharge : 2.5 m/s

In DM/ condensate transfer piping (stainless steel pipe handling clean DM water), higher velocity (upto 6 m/s) shall be considered, as in CEP/BFP discharge piping handling similar quality of water.

Agreed.


Ch 27 : Low Pressure Piping,Valves & SpecialitiesSheet 2 of 35

27.1.3 In WILLIAM & HAZEN formula, C value is mentioned as 100 for stainless steel pipe. In WILLIAM & HAZEN formula, C value shall be taken as 140 for SS pipe carrying clean DM water.

Agreed.



26.1.2 (ii) Pressure drop in main steam line shall not be more than 90% of the allowable pressure differential----

As the pressure drop shall be calculated accurately and exactly as per actual piping layout, additional margin is not required. Additional margin will result in oversized pipe sizes which is not desirable.




26.1.2 (i) Auxiliary steam- 40 m/s As aux. steam parameters 16 Kg/cm² (a) and 290°C which is adequately superheated, velocity can go upto 76 m/s as allowed for superheated steam.


PAGE 29 OF 75




244 Vol.-II, Generals & Schedules

Ch 5 : General TechnicalRequirementSheet 42 of 91

40.2 The Power Plant will be developed based on the guidelines of the State Environmental Authorities and that of MoEF. Suitable provisions will beincorporated in the design of buildings, structures, and selection of equipment, so that there are no adverse effects due to emissions, noise, andcontamination of soil, water and air.

One single flue stack of 275 meter will be provided for 660 MW unit for widerdispersion of pollutant as per environmental guidelines.

As per MOEF guidelines, for Thermal Power plants with FGD, stack height/limit is given as : H=6.902(QX0.277)0.555or100 m whichever is more.

Q = Emission rate of SO2 in kg/hrH = Physical stack height in meter.”

275 m tall chimney is too high as per the above MOEF guidelines. Chimney height may be reviewed. Accordingly kindly inform the Chimney Height to be considered .

Reffer Amendment -04.


Ch 9 : Mandatory SparesSheet 15 of 106

2.15 -A(2) Steam pressure reducing cumdesuperheating valves= 1 NO

Items covered under A 2(a) to 2(f) are spare parts of High capacIty PRDS system and under A (2) complete Steam Pressure reducing cum desuperheating valve is also mentioned as SPARE, we understand that it is typographical mistake.Please review the requirement under A(2). Same will not be considered as SPARE since it is complete control valve & not Spare.

Agreed



2.15 -B(1) Steam pressure reducing valve= 1 NO Items covered under B 1(a) to 1(f) are spare parts of Low capacity PRDS system and under B (1) complete Steam pressure reducing valve is also mentioned as SPARE,we understand that it is typographical mistake.Please review the requirement under B(1). Same will not be considered as SPARE since it is complete control valve & not spare.

Agreed



2.15 -B(2)(a) Spray water line control valves :Valve trim including cage, plug,stem, seat rings, guide bushings,stem packing = 1 no.

Items covered under B 2(a) are not applicable for the Low capacity PRDS system.Please review the requirement under B(2)(a). Same will not be considered as SPARE since it is not applicable as per the P&ID of Aux Steam System, DWG. No. 111-11-0300.

Agreed



2.15 -A(1) A)High Capacity PRDS System (MS)1.Desuperheater liners

Desuperheater liners as mandatory spares item for HCPRDS is not applicable as per the design being offered by vendor's for Aux-PRDS.


249 Volume VI :Civil, Structural & Architectural Works

Ch 12 : RCC ChimneySheet | 7 of 22

12.5.2 The flue diameter shall be so sized to ensure that the flue gas exit velocity is of the order of 20 to 25 meters/second at the normal continuous operating load. It should be ensured that the flue gas exit velocity at the lowest continuous unit load is high enough (of the order of 15 meters/second) to enable adequate dispersion of the flue gases.

We understand that the velocities indicated are for DRY STACK,whereas in this Project Wet Stack is applicable.

As per EPRI Wet Stack Design, the recommended liner-velocities are lower for different liner materials (16.8 m/sec for Titanium and 18.3 m/sec for Borosilicate etc). Customer to confirm Flue Gas Velocity through both above said Liners at normal continuous operating load & also inform technical requirement details (if any) for condensate flow model study for Chimney.


250 Volume III / Mechanical Works

Ch-29 plant layout requirement, page no. 2 of 10, clause no. 29.1.2.6

Two (2) 950 kg (one at each end of the turbine building) conventional passenger elevator for Turbine building. This elevator shall travel up to Deaerator floor level.


Ch-33 plant layout requirement, page no. 12 of 15, clause no. 34

Two (2) nos. conventional type elevators shall be provided inside the TG building on both ends of the building. For further technical details refer respective portion of the Technical Specification.

252 Tender drawing: TG Building floor plan at EL+8.5M, & 17.0 M (Drg. No. 111-21-0300 Rev-00)

Three (03) nos. elevator well are indicated in BC bay.

1088 kg elevators shall be considered instead of 950 kg.

MAUX(Elevator)

Customer to clarify the following points.• Capacity of elevator i.e. 950 Kg is not as per standard code IS: 14665 followed for elevator. Elevator capacity 884 Kg (13 persons) shall be provided in line with IS: 14665.

Please accept & confirm 884 Kg capacity in lieu of 950 kg.

• As per referred clause and TG building layout, there is contradiction in quantity of elevator. Hence as per standard practice, two (02) nos. 884 Kg Capacity of conventional passenger elevator shall be provided. No. of Elevator & Capacity of Each Elevator may please be confirmed.

PAGE 30 OF 75




253 Volume III / Mechanical Works,


Two (2) 950 kg conventional VIP passenger elevators for Service Building. Capacity of elevator i.e. 950 Kg is not as per standard code IS: 14665 followed for elevator. Conventional type Passenger elevator conventional type capacity 884 Kg (13 persons) shall be provided in line with IS: 14665.

Please confirm.



Two (2)- 950 kg conventional passenger elevators, one for each ESP/VFD Control Building.

Capacity of elevator i.e. 950 Kg is not as per standard code IS: 14665 followed for elevator. Elevator capacity 884 Kg (13 persons) shall be provided in line with IS: 14665.

Please confirm.


Ch-29 plant layout requirement, page no. 2 of 10, clause no. 29.3.3.2 (iv).

False ceiling : Powder Coated. Since, elevator car, and ceilings shall be of SS 304, False ceiling shall be of SS 304 accordingly. Hence, it cannot be powder painted. Confirm the acceptance.

Confirmed.


Ch-29 plant layout requirement, page no. 2 of 10, clause no. 29.3.4.1 (4).

Bidder shall provide emergency indicator to indicate the location of elevator in case of elevator being stuck up between the floors through automatic flashers (both audio and visual).

There are two condition which are envisaged for stuck-up of elevator: • If the elevator is stuck between floors in power condition, the floor indicator will be visible with a message – “Out of Service”.• If the elevator is stuck between floors in Power-off condition, the floor indicator will not be available. Once power is restored the lift moves to the nearest landing & the indicator will get updated.

Further, as per reputed / regular elevator suppliers stuck-up condition positioning of elevator cannot be indicated in either of above condition.

Will be reviewed and finalized during detailed engineering.

257 Volume II. General & Schedules

Ch 9: Mandatory Spares

Sheet 59 of 106 ( c ) Mandatory spares: Service Elevator. Mandatory spares for each building elevator shall be provided as follows in line with the cl. No. (C ), mandatory spares ( s.no. 1 to 32) page no. 59 of 106, ch:9 of tender technical specification .

a) One (01) common Lot of list of spares (as applicable) for TG Building elevators.b) One (01) common Lot of list of spares (as applicable) for Service Building elevators.c) One (01) common Lot of list of spares (as applicable) for ESP Building elevators.

Kindly review and provide confirmation.

Agreed.

1088 kg elevators shall be considered.

PAGE 31 OF 75




258 Volume IIIMechanical Works

Ch 1: SG & AuxiliariesSection 1 : ScopeSheet 39 of 47

1.7 MILL REJECT HANDLING SYSTEM

(d) Mill rejects storage silos (2) no. for each unit in steel construction each having an effective storage capacity of sixteen (16) hours considering the number of mills connected to each silo and rejecting @ of 1% of mill capacity for the worst coal conditions/ or maximum actual, whichever higher.




Each silo shall have an effective storage capacity of sixteen (16) hours considering each mill in the bay rejecting @ 2.0% of mill capacity correspondingto unit operation at 100% BMCR with worst coal firing.


Ch 20 : Mill RejectHandling SystemSheet 6 of 7

DATA SHEET FOR MILL REJECT HANDLIMG SYSTEM

1.0 MILL REJECT SYSTEMd. Rate of Rejects Generated per mill - 2.0% of mill capacity or maximum actual whichever is higher


Part B, Chapter 4 : MainEquipment Related C&IsystemSheet | 13 of 23

4.17.00 MILL REJECT SYSTEM C&I WORK

For Silo level measurement, 3-D Acoustic Wave Level Transmitter with necessary software forVolume measurement shall be provided.


Vol. V: PART ASheet | 98 of 100

4.00.00 Level Measurement vi) Each Mill reject storage silo must be provided with 3 nos. level switch (switches 2 nos. for very high level and One no. for high level.)




4.0 MILL REJECT SILOc. Type of level measurement and indicator - Continuous/ RF Type



20.2.3 Mill Reject Silo Adequately sized bag filter to vent the transport air to atmosphere, terminal boxes, 3D level Acoustic transmitter and pressure relief valve shall be provided on the top of storage silo.


Ch 24 : Fire Detection, Alarm & Protection SystemSheet 4 of 70

A) Hydrant system protects the following building/facilities:

A) Hydrant system protects the following building/facilities:iii) Mill Reject Handling System compressor house.



CHAPTER 20 : MILL REJECT HANDLING SYSTEM

20.1.2 Compressors shall be located in the ash handlingcompressor house.




20.2 j) Three (3) (1W/unit + 1S) oil free screw compressors, with drives & accessories, to cater to the conveying air requirements of mill reject handling system. Compressors shall be located in Compressor House of Ash Handling System.


Ch 1: SG & AuxiliariesSection 2 : Design Basis ofSG & Auxiliaries and SCRSheet | 41 of 120

2.10.5.23. Mill Rejects System: iii) The necessary mill isolation dampers/valves, to facilitate automatic continuous or automatic intermittent discharge of rejects to the conveyor.

Pneumatic type mill reject system is being offered as per customer specification. There is no "conveyor" in the system. Kindly confirm.

Confirmed.

2% shall be considered.

3D Acoustic wave level transmitter shall be provided.

Confirmed.

Mill Reject Compressors shall be located in Ash Handling Compressor House.

Different requirements have been specified against different clauses. Generally 1% mill capacity for the worst coal conditions/ or maximum actual, whichever higher is considered for designing of the mill reject system and mill reject silo.

Kindly confirm.

Different requirements have been specified against different clauses.

Generally RF level switch is provided for measurement of high level in silo for stopping conveying system, in case of high is achieved in silo and there is no discharge of rejects from silo.

We propose one no. RF level switch with one no. RF level switch as redundant. Kindly confirm

Compressors of Mill Reject System are proposed to be placed in Main Plant Compressor House. No separate compressor house is being considered. Kindly confirm.

MAUX(Mill Reject System)

PAGE 32 OF 75




269 Volume VII-TD-Mechanical

TENDER DRAWINGS-MECHANICAL

FLOW DIAGRAM - COMPRESSED AIR SYSTEM (DWG NO. 111-14-6100)

A tapping for Mill Rejects System has been shown from the service air header. As per customer specification, separate dedicated compressors for conveying air of Mill Reject System are to be given. But in the referred flow diagram, tapping from Main Plant Compressed Air System's Service Air Header has been shown. It is preferable to have dedicated mill reject compressors. Kindly clarify.

Dedicated Compressors shall be considered.

270 Volume II :General & Schedules

Sch. B : Technical Schedule-Steam Generator & AuxiliariesSheet 67 of 152

38.0 MILL REJECT SYSTEM38.1 Pneumatic ConveyingSystem

ix. Power consumption of air handling units (kw) There are no air handling unit in mill reject handling system. Requirement not clear. Kindly clarify.

No air handling units in Mill Reject System.

271 Volume IIGeneral & Schedules

Sch. B : Technical Particulars(Mill Reject Handling system)Sheet 1 of 1

1.0 MILL REJECT SYSTEM h. Mill reject conveying capacity Impeller (TPH) Requirement not clear. Kindly clarify. Please ignore word "Impeller".




The storage silos shall be designed to provide a clear access of 4.5 m for a Road Tanker/Trucks to come under the silo & receive the rejects using suitable chute work.




20.2 g) The storage silo shall be designed to provide a clear access of 5 m for trucks to come under the silo and receive the rejects using suitable chute work.



20.2.2 Mill Reject Vessel Mill reject vessel shall be provided with one pneumatic cylinder operated inlet valve (material handling valve), outlet valve and air inlet valve……...At predetermined pressure, the outlet valve of mill reject vessel opens and rejects are conveyed to reject silo/storage silo through pipeline. As evacuation proceeds, vessel pressure drops and at a predetermined pressure, air inlet valve and outlet valve closes and the system gets ready for the nextbatch evacuation, commencement of which is signalled by level probe in the pyrite hopper.


Ch. 1: SG & AuxiliariesSection 1 : ScopeSheet 39 of 47


d) One (1) Mill Reject vessel below each pyrite hopper with pneumatically operated inlet/outlet valves, necessary instrumentation (level probesetc.).




The configuration of Plant DDCMIS shall be as per system configuration drawing FOS PLC# 114-01-0100, Rev-0. The operation and control shall be performed from FOS Control Room as well as CCR.

Requirement not clear. We propose DCS based control system for mill reject handling system with local control panel near each stack assembly. Kindly confirm.





The mandatory spares for Mill Reject C&I items shall be as per relevant section. The mandatory spares shall be separate for each SG Auxiliary package.

From this statement, we understand that the applicable mandatory spares for mill reject system are to be considered from III. CONTROL & INSTRUMENTATION (MANDATORY SPARES), Ch. 9 : Mandatory Spares, Volume II (General & Schedules).Kindly confirm.

Confirmed.

5 M Clear Access shall be considered.

Confirmed.

Different requirements have been specified against different clauses.

Generally 4.5 m clear access is provided under the mill reject silo for road tanker/trucks. Kindly confirm.

Valve at mill reject vessel outlet is provided for pneumatic conveying where multiple vessels are connected in one common line. In mill reject handling system dedicated lines per vessel is provided for which valve at vessel outlet is not required. Kindly confirm.

PAGE 33 OF 75





Ch. 20 : Mill RejectHandling SystemSheet 6 of 7


2.0 MILL REJECT HANDLING VALVESe) Sizing Grid - Yes (To separate oversize rejects/ togive control feed to crushers, if proposed)



NOTE: 1. *In case the bidder expects higher size from pyrite hopper outlet, then suitable capacity crusher shall be provided to bring down size of reject to (–) 40mm forpneumatic type system offered, which shall be included in the base offer.


Ch 1: SG & AuxiliariesSection 2 : Design Basis ofSG & Auxiliaries and SCRSheet | 33 of 120

2.10.1. iii) Coal Bunker(s) (c) Minimum thickness of structural steel bunker plates shall be 12mm inclusive of 4 mm corrosion allowance. Minimum wallthickness of hopper shall be 8 mm. Minimum thickness of stainlesssteel liner on the inner surface of hopper wall shall be 4 mmconfirming to grade SS 304.


Ch 07 : MaterialSheet | 1 of 1

7.1 Structural Steel Complete hopper including vertical and conical portion of bunker in millbuilding shall be provided with lining of atleast 4 mm thick SS plate grade SS316L.


Ch 11 : BuildingDescriptionSheet | 6 of 16

11.3 MILL AND BUNKER BAY BUILDING

Stainless steel liners shall be provided in bunkers for the conical / hyperbolicas well as vertical portion of Bunker. The grade of SS liner shall be SS316L.

283 VOLUME-I SECTION – I 2.0 / Page 4 of 56 Following works will be excluded from the bidder’s scope:i) Procurement/Supply of ………… fire tenders.

Pl. confirm the bidder’s scope w.r.t. Fire Tender along with fire safety equipment. As herein the Fire tenders excluded from bidder’s scope whereas as per specification “VOLUME-III / Ch 24 : Fire Detection, Alarm & Protection System / 24.4.10 / Sheet 53 of 70”, fire tenders along with fire safety equipment are to be supplied by bidder. Discrepancy wrt scope may please be rectified.Pl. confirm.

Only Fire Tenders will be procured by Owner.

284 VOLUME-III Ch 24 : Fire Detection, Alarm & Protection System /

24.4.10 / Sheet 53 of 70 Two (2) No. mobile Fire Tender, One (1) dry chemical tender and One (1) No. mobile Foam Tender shall be provided.

The design requirements of mobile water tender shall conform to IS 950 and design requirements of mobile Foam tender shall conform to IS 10460.

Type of fire tender are specified as DCP and Foam Tenders, Clarity is absent for quantity of fire tenders to be supplied i.e Four or Two.

Also as per civil specification, customer have asked parking space for two nos. fire tender.

As per para-2, design standard for water tender (IS: 950) and foam tender (IS:10460) are specified, but the design standard for DCP tender is not mentioned in specification. There is no water tender quantity mentioned, however design standard is specified.

From the given clauses, para–1 and other related requirements, Bidder understands that two nos. fire tenders (One no. Foam Tender as per IS: 10460 and one no. DCP tender as per IS: 10993) are to be supplied for the project.

Fire Tenders will be procured by Owner.

Confirmed.

SS316L on both vertical & conical portions to be followed.

MAUX(FIRE TENDER)

90-95% of mill rejects are generally below 40mm size. Sizes above 40mm are collected above the sizing grid and removed through oversize valve. No separate crusher is envisaged.

MAUX(BUNKER)

Kindly clarify the type (SS304 or SS316L) and extent of liner (on conical portion only or conical as well as vertical portions of bunker)

PAGE 34 OF 75




285 Volume VI Ch 11 : Building Description

11.12.5 / Sheet 11 of 16 Provision for parking of 2 fire tenders including 1 bay for maintenance with pit, office, duty room, stores, recreating room, record room and toilet blocks shall also be made.

Bidder understands that maintenance bay can also be used for parking the Fire tender, i.e. out of total two bays for parking, one bay shall be maintenance cum parking bay.Pl. confirm.

Fire Tenders will be parked in Fire Station.


11.12.5 / Sheet 11 of 16 In addition adequate space shall be provided for hose drying and drill ground. Specification is not clear w.r.t. requirement of Drill tower.Pl. confirm the bidder scope w.r.t. Drill tower.

Drill tower is part of drill ground.

287 VOLUME-III Chapter - 23 : Compressed Air System

23.6.7 (a) / Sheet 12 of 20 The air drying units shall be of 99.7% efficiency allowing a maximum pressure drop of 0.3 kg/cm2 (g)

Pl. note that the max. drop across HOC type air drying plane shall be 0.5 kg/cm2 (g).This is in line with the industry practice and also as per customer specification clause no. 23.4.3 “The normal pressure of Instrument Air supply at the outlet of Air Dryer shall be 8.0 kg/cm2 (g)” w.r.t. compressor discharge pressure of 8.5 kg/cm2 (g).Pl. accept.

Confirmed.


23.4.7 / Sheet 4 of 20 Each air compressor shall have its own control panel with indication lights for power on; service hour-run meter; load hour-run meter; inlet air filterdifferential pressure high; outlet air pressure & temperature (analogue gauge); oil filter differential pressure high; separator element differential high; motor overload; low oil level; compressor temperature high; oil temperature before and after oil cooler (analog gauge). The compressor should trip on motor overload; low oil level; and compressor temperature high.

Pl. note that the same shall be as per compressor OEM standard and its proven design, taking into consideration all the safety aspects for successful running of compressors.

Pl. accept.

Confirmed.


23.4.8 (i) / Sheet 5 of 20 The total Service Air requirement shall be assessed by considering thefollowing guideline:Y = {(2xE+F)+G+H} x [1+ (mw+ml)/100] where…………………….G= Service Air Requirement for AHPH= Service Air Requirement for CHP

Pl. note that dedicated compressors for AHP and CHP shall be provided.This is also as per customer specification clause no. “23.1.2 Besides, dedicated Compressed Air Systems shall be provided for each of the following areas:(a) CHP area(b) AHP area”.

Bidder has not considered the requirement of above systems, while sizing main plant compressors capacity.Pl. accept.

Confirmed.


23.4.15 / Sheet 6 of 20 Each Air Receiver shall be so sized that even in the event of total stoppage of air inflow to the same, the pressure in the Air Receiver shall not fall below 5.5 kg/cm2 (g) within two (2) minutes of such stoppage, while maintaining an out flow of air at a rate equal to the rated capacity of a single compressor, during the aforesaid period

Sizing of air receivers considering cl. No. 23.4 15 will lead to very bulky size of air receivers. Bidder will offer air receiver sizes as mentioned in P&ID and datasheets. Please accept.

15 M3

MAUX(COMPRESSED AIR SYSTEM)

PAGE 35 OF 75





23.5.1 (a) / Sheet 7 of 20 The Instrument Air System shall include but not limited to the following:a. Three (3) (1 working per unit + 1 common standby), oil free, dry screw type, water cooled, horizontal multistage rotary screw Compressors.

Since, the compressors are of higher capacity i.e. 55 NM3/min. minimum & there are limited suppliers for such high range capacity compressors, as most of manufacturers manufacture oil free screw compressors up to rating of 40 NM3/minute & beyond 40 NM3/minute, multistage centrifugal compressors, to achieve best economics of scale. We request to accept Centrifugal compressors also as an option considering the availability and machine efficiency in this range.

Confirmed.

VOLUME-III Chapter - 23 : Compressed Air System

23.5.1 (h) / Sheet 7 of 20 DM plant area it shall be minimum 2 M³.


DATA SHEET 8.2.1 / Sheet 18 of 20

One (1)- 5 Cum for DM plant


23.5.1 (h) / Sheet 7 of 20


23.5.2 (f) / Sheet 8 of 20


23.6.1 (o) / Sheet 9 of 20 Each compressor shall be provided with name plate, base plate, anchor bolts and shim packs, anti-vibration pads, eye bolts, operation & maintenance tools.

Pl. note that in case of Oil free screw compressors, same shall be rested on foundation without any anchoring.This is in line with the industry practice and manufacturer proven design.

Pl. accept.

Confirmed.


23.6.2 (b) / Sheet 9 of 20 The lubricant pump shall be shaft driven Pl. note that the lubrication pump designs shall be as per OEM standard and its proven design, taking into consideration all the safety aspects for successful running of compressors.Pl. accept.

Confirmed.


23.6.7 (a) / Sheet 12 of 20 Heat of compression type (HOC) Air drying plants shall be provided for instrument air requirement. Capacity of each air drying plant shall be 125% of Instrument air compressor

Please note we have kept Air Drying Plant capacity identical to Instrument air compressor capacity in line with industry practice for 500 MW/660 MW/800 MW power plants.Also air dryers performs best in case of getting the flow for which they are designed for.Please accept



23.6.7 (d) / Sheet 12 of 20 The absorbers shall be sized so that even when the compressor is operating at part load, complete regeneration shall be achieved within the cycle time and quality of air (dew point) shall be maintained throughout the design cycle period.

Please note oil free screw compressors are being envisaged as per specification, which operates either at no load or full load.Bidder have furnished its offer considering load / unload feature of compressors. Part load operation of compressor is not envisaged by bidder.Pl. accept.

Confirmed.


DATA SHEET 2.8 / Sheet 15 of 20 Number of starts per hour : 8 (equally spread) Since HT motors are envisaged for Compressed air system, the no. of starts shall be limited to 2 hot start per hour.Pl. accept.



DATA SHEET 8.2.1 / Sheet 18 of 20

Two (2) – 10 Cum each- unit airreceivers

VOLUME-VII TD FLOW DIAGRAM COMPRESSSED AIR SYSTEM: DWG NO.-111-14-6100, REV.00

UNIT AIR RECEIVERS CAP : 15M3 (EACH) (AT TG BUILDING)

VOLUME-I ATTACHMENT – 8 / I (vii / PAGE 2 OF 14

(vii) Air Compressors and Air drying plant guarantees in accordance with, clause 1.03.22, Ch- 8, Book 1 of 2, Vol-II


5 M3

Confirmed.

15 M3 capacity

PLC based control panel for control and monitoring of the Compressedair system, field instruments, control cables, etc.

Skid mounted Microprocessor based control system shall be provided for compressors integral control as per OEM practice. Additionally, Stand-alone System as per Vol-V of specification shall be provided by bidder. Separate PLC for CAS is not envisaged by bidder.Pl. accept.

300 There is ambiguity in the two clauses specified.Pl. confirm the capacity of Unit air receiver to be consider by bidder.

301 The clause 1.03.22 specified is not available in the given Vol-II.Pl. check and furnish the referred clause.

Also there is mismatch in the page nos. of the Attachment – 8.

292 There is ambiguity in the two clauses specified.Pl. confirm the capacity of DM plant air receiver to be consider by bidder.

PAGE 36 OF 75




VOLUME-I ATTACHMENT – 8 / XXI / PAGE 16 OF 16

XXI. Air Compressor SystemWe confirm Guarantee in accordance with Clause no. 1.03.22, Ch- 8, Book 1 of 2, Vol-II of Technical Specification.


302 VOLUME-III Ch 33: Plant Layout Requirement

33.10 (g) / Sheet 14 of 15 Space for additional one (1) no. IA compressor, additional one (1) no. SA compressor. Bidder understands that additional space for one no, air drying plant is also required for future provision.Pl. confirm.

Confirmed.

303 VOLUME-II Ch 9 : Mandatory Spares

11.00 (19) / Sheet 53 of 106 Air drying plant The specification calls for HOC type air drying plant. However the mandatory spares are specified for Refrigerant type air drying plat.Pl. furnish the list of required mandatory spares for HOC type air drying plant.



11.14 / Sheet 13 of 16 Unloading pump houses to unload oil from road tankers or rail wagons shall be of single storey……

Bidder have considered only road unloading in line with tender dwg. “Flow diagram LDO unloading system: 111-11-1130, Rev.00”.Rail unloading is not envisaged by bidder.Pl. confirm.

Confirmed.

305 Volume V PART A 5.00.00 (j) / Sheet 99 of 100 HFO/LDO flow meters shall be based on coriolis mass flow technology. Fuel Oil meters shall be provided for fuel oil unloading system and near boiler after day oil tank (at main supply & return line).

1.) Pl. note that HFO system is not envisaged for the project.2.) Pl. note that Day oil tank is envisaged for Auxiliary boiler only as per mechanical specification.Further, Flow meter is provided as per tender dwg. “Flow diagram LDO unloading system: 111-11-1130, Rev.00”. The requirement of flow meter at main supply & return line for Auxiliary boiler day oil tank is not shown in the above P&ID and is not considered by bidder.

Pl. accept.

Flow meter at main supply & return line for Aux. Boiler shall also be considered.

306 VOLUME-I ATTACHMENT – 8 IX / PAGE 5 OF 14 (a) Capacity, total dynamic head either in isolation or during parallel operation of:(i) HFO unloading pump(a) HFO Storage tank capacity................. KL

Pl. note that HFO system is not envisaged for the project and hence bidder understands that the specified clauses are not applicable.Pl. confirm.

Confirmed.

307 Volume III&Volume VII

CHAPTER 09&Tender Drawing

9.2.3 (ii) In addition to the dissolved solids, the influent condensate shall also contain some quantities of suspended solids (crud) derived from the---------------------------Pre filters, to be used for this purpose shall be of regenerating type.& Flow Diagram Condensate Polishing Unit Sh. 1 of 2 (111-12-3510)

As per referred clause, Pre-Filter need to be used. However as per Flow diagram Pre-Filer is not applicable. Please confirm.

Prefilters are to be used.

308 Volume III CHAPTER 09 9.2.3 (ii) In addition to the dissolved solids, the influent condensate shall also contain some quantities of suspended solids (crud) derived from the---------------------------Pre filters, to be used for this purpose shall be of regenerating type.

We understand that the If Pre-Filters is applicable, then the same shall be employed for the commissioning period, start up period as well as normal continuous operation.Please confirm.

The same is to be used during Startup & Commissioning period.

310 Volume III CHAPTER 09 9.2.3 (ii) In addition to the dissolved solids, the influent condensate shall also contain some quantities of suspended solids (crud) derived from the Pre filters, to be used for this purpose shall be of regenerating type.

The configartion & Cycle period details of Pre-Filters has not been provided.Please provide.

Refer amendment -04.

311 Volume III CHAPTER 09 9.2.11(xiv) Analytical Instruments (Normal)The polisher units shall be provided at common inlet and each outlet unit with a minimum of following analytical on line analysers:- pH Analyser- Conductivity Analyser- Cation Conductivity Analyser- Sodium Analyser- Silica Analyser- Chloride Analyser

The sodium analyser shall be of Multi-Channel type.Please confirm.

Confirmed.

MAUX(Cranes)

MAUX(FUEL OIL UNLOADING SYSTEM)

MAUX(CPU-Condensate Polishing Unit)

PAGE 37 OF 75




We understand that the requirement of EOT cranes mentioned in the said clause of proven-ness criteria includes Double Girder EOT Cranes, Gantry Cranes, Semi-Gantry Cranes etc. since design of all these types of cranes are governed by similar Indian Standards (design of Gantry/Semi-Gantry Crane being more strin-gent w.r.t. requirement of wind load design of these cranes). Please confirm.

Confirmed.

Since Double Girder EOT Cranes supplied in power station are designed based on similar Indian Standard (i.e. IS 3177 and IS 807) as for any other building viz. manufacturing units, cement factories, oil refineries, shipyards, Steel Plant (which is comparatively heavier duty w.r.t power station), workshop sheds etc; we understand that the word ‘station’ indicated in provenness criteria includes crane supplied in any of the said buildings and not only power station.Please confirm

313 Volume II Ch11 : QAP (Mechanical)

2.8 (7), Sheet 11 of 94 The cranes shall be completely assembled at shop for final testing. All tests for dimension, deflection, load, overload, hoisting motion, cross travel etc. as per IS-3177 shall be carried out at shop.

All tests for hoisting & Cross travel shall be demonstrated at Works. However LT i.e Long travel motion testing cannot be shown at Works since the required civil structure including rail to suit the crane span cannot be developed at manufacturer's works. The same shall be demonstrated at site.

Agreed

314 Volume II Ch 9 : Mandatory Spares-

23,Sheet 67 of 106 EOT CRANES & Hoists (FOR EACH TYPE & CAPACITY) We understand the the spare listed in the referred clause of I- Mechnical packages is comprehensive list of mandatory spares for cranes & hoists. Any other item indicated under II- Electrical packages & III-CONTROL & INSTRUMENTATION packages is not being considered for cranes & hoists.Please confirm.

Confirmed.

Volume III : Ch 28 : Cranes & Hoists

28.2.2,Sheet 3 of 15 “In addition, it shall also be possible to handle Generator Stator with tandem operation of two Turbine hall EOT cranes for which necessary arrangements shall be provided. In such case, the combined capacity of two EOT cranes shall not be less than the 110% of weight of Generator Stator.”


28.3 (a) , Sheet 5 of 15 TURBINE HALL EOT CRANE: Each crane shall be capable of lifting at least 110% of the weight of single heaviest component/equipment, including slings etc. (as applicable) to be handled in TG hall for erection as well as maintenance of the equipment provided in AB bay. Crane capacity shall be minimum 310/ 30 T.

316 Volume III : Ch 28 : Cranes & Hoists

28.1.3 (x.), Sheet 2 of 15 Air Compressor Room (Double Girder Overhead EOT Crane) Normally the crane capacity in compressor house is in range of 5T to 10T for which single girder crane is sufficient. As such double girder cranes is not re-quired, as it will unnecessarily increase the building height and load the Civil structure. Kindly accept



28.2.3 , Sheet 3 of 15 Auxiliary Hook of 10 T shall be provided in the cane for handling BFP. The Provision as per bidding specification shall prevail.

Refer Amendment.No.-04

317

315 Please note that contradictory requirements have been mentioned. We propose the following1) Each crane shall be capable of lifting 110% of heaviest component/equipment ( other than generator stator) including slings etc to be handled in TG hall for erection as well as maintenance.2) “In addition, it shall also be possible to handle Generator Stator with tandem operation of two Turbine hall EOT cranes for which necessary arrangements shall be provided. In such case, the combined capacity of two EOT cranes shall not be less than the 110% of weight of Generator Stator.3) The minimum crane capacity requirment of 310/30T may be deleted, since it will unnecessaraliy load the TG building Civil structure beyond its actual practical purpose and also affect layout requirement. Cranes shall be designed as per above criteria which will fulfill the layout requirement as well as optimize the Civil load.

In BFP building & CW pump house , the width of building /pump house is not very high. Providing Auxiliary hook will not serve any significant purpose since all the components to be handled are within the approach of the single hook provided. Addition of Aux hook will affect the approach of main hook. Kindly review and confirm deletion of Aux hook requirement.

Volume II Ch 4 : Provenness 4.15, Sheet 12 of 40 The Bidder/its sub-vendor should have designed, manufactured, erected and commissioned EOT cranes of capacity 100T or more with minimum crane span of 28 meters, which is in successful operation in at least Two (2) station for a minimum period of one (1) year prior to the date of Techno-Commercial bid opening.

312

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28.2.4 , Sheet 3 of 15 The CW umphouse EOT crane shall be provided with an auxiliary hook of 10 T capacity.


28.2.4 , Sheet 4 of 15 The rated capacity of all the other cranes shall be 25% over and above the heaviest component/ equipment to be handled including slings

For CWPH crane as per previous projects 10% margin is adequate. Increasing the crane capacity increases the load on civil structure .Please accept with 10% margin since the layout and crane with this consideration have already been executed/under execution for various projects. For cranes of other areas 25% margin shall be considered.Kindly confirm acceptance.



28.2.11 , Sheet 4 of 15 The EOT cranes shall be designed to operate with 125% of rated load without any permanent deformation (other than TG building EOT Crane which shall be 110%)

Kindly clarify meaning of “rated load”. We understand the same means the safe working load of crane. It may be noted that cranes are designed to operate without any permanent deformation at 100% of Safe working load ( which has a margin of 110 % over heaviest weight to be lifted for TG hall /BC bay/CW PH cranes and 125% margin for other areas cranes). Further the cranes are also overload tested at 125% of safe working load.

Rated load - Safe working load of Crane.

Follow specification for design.

Volume II Ch 5 : General TechnicalRequirement

7.2.3,Sheet 4 of 91 Lifting devices i.e. hoists and chain pulley jacks, etc. shall be provided by the Bidder for handling of any equipment or any of its part having weight in excess of 500 Kgs during erection and maintenance activities.


28.2.12 , Sheet 4 of 15 For items weighing 300 kg and above, hoists and trolleys along with monorails shall be provided throughout the plant where crane cannot be utilized.


28.2.12 , Sheet 4 of 15 All hoists shall be provided with trolleys. In case of manual hoists it is not possible to provide trolley type due to layout and headroom constraints in some areas. However wherever possible trolley type shall be provided depending on layout.

Confirmed.


28.2.12 , Sheet 4 of 15 Hoists and Trolleys with Monorails For electric hoists speeds have not been indicated. Same shall be as follows 1) Hoisting -2.5 to 3 Metres per minute2) Cross travel-7 to 10 metres per minute.

Further creep speed is not considered.

Agreed.


28.3 , (viii) (i) Sheet 6 of 15 Access walkways of not less than 800 mm (clear) with hand railing of height of 1100 mm along both sides of bridge girder and cross over walkways

800 mm clear for cross over walkway is on conservative side. Please note that the crab is accessed only during maintenance and not regularly. Hence a walkway of 400-500 mm is adequate. Increasing the crab walkway affects the hook approaches. However we confirm that 400mm is minimum and better shall be provided depending on detail engineering.

500 mm access walkways shall be provided.

Runway/trolley Rails and rail joints. Rails to be as per relevant Indian Standard and joints to be butt welded by Thermit welding or fusion welding.

Rail to rail joints may be allowed by end clamping method also. Welding of rail and its associated tests are very difficult to carry out at site

320 Different requirement have been indicated wrt item weights . Kindly review the criteria. As per our practice dedicated handling arrangement is provided for any equipment or any of its parts having weight in excess of 500 kgs based on feasibilty of layout.

28.3,(xiv)Sheet 7 of 15 Ch 28 : Cranes & Hoists

Volume III : 324

Confirmed.

Agreed.

PAGE 39 OF 75




One (1) no of Electrically operated travelling crane for each unit with provided in the BC bay for erection and maintenance of Boiler feed pump and their auxiliaries.


28.4.16 ,Sheet 9 of 15 The vertical deflection of crane girder shall not exceed 1/800 of the span,as per IS: 807. As per IS 807 the vertical deflection of the crane shall be 1/750 of the span of the crane (if the span of the cranes is more than 12m), and 1/600 of the span (if the span of the crane is less than12m).Kindly confirm.

Confirmed.


28.5.1 ,Sheet 10 of 15 The EOT cranes for all other areas indicated in clause 28.1.3 above shall meet all the requirements indicated in clause 28.4 above.

Noted for double girder EOT cranes of BFP – BC bay and CW pump house. For single girder cranesor other areas like in Intake Pump House,Raw Water Pump House DG building, Work shop, compressor house etc only DC electromagnetic type brakes can be provided. Thruster type brakes are not recommended for single girder cranes due to mounting and alignment issues.Further the quantity of brakes that can be provided per motion in case of single girder cranes and hoist is one only due to limitation of space.

Agreed.


28.5.1 ,Sheet 10 of 15 The EOT cranes for all other areas indicated in clause 28.1.3 above shall meet all the requirements indicated in clause 28.4 above.

Noted for double girder EOT cranes of BFP – BC bay crane and CW pump house crane. For other areas like in Intake Pump House,Raw Water Pump House DG building, Work shop, compressor house etc where single girder cranes are to be provided, platform on crane bridge girder cannot be provided.The cranes structure being single girder, the platform cannot be supported on the crane structure. For maintenance purpose suitable platform along with acess ladder shall be provided at the end of bay at operating floor.For same reason/s mentioned above , ladder to approach the bridge platform of these other areas cranes are also not required.Kindly review and confirm.

Agreed.


28.6.1 ,Sheet 10 of 15 Electrical equipment shall be adequately rated to permit simultaneous operation of any combination of motions of the crane for it duty service.

The crane control is designed for simultaneous operation of any two motions. i.e Main and Aux hook ,Main and Cross travel, Main and long travel, Aux and cross travel or aux and long travel, which ever is more stringent.

Agreed.

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28.6.2.3 ,Sheet 10 of 15 Motor ratings shall be 25% (at least) over the maximum power requirement. The hoist motors shall be rated to lift 125% of the design load at rated speed.

We understand that the design load is the safe working load of the crane. Kindly inform if understanding is correct.Further 25% margin may please be reviewed since 15% over maximum power is sufficient, as provided for numerous cranes supplied and installed in earlier projects. Over rated motor will ultimately add to capital and running cost.



28.6.3( iv)Sheet 11 of 15 VVVF system shall be capable of generating suitable starting torque (upto 400 % typical). For VVVF system 200% starting torque is adequate. Kindly accept. The provision as per bidding specification shall prevail.


28.6.4 ( iv)Sheet 12 of 15 Radio remote Control of EOT Crane: We understand that only TG hall EOT crane shall be Radio remote control operated along with cabin. For cranes of other areas pendent push button operation is required in line with requirement mentioned at clause no 28.2.8, sheet 3 of 15. Kindly clarify.

Only TG Building EOT crane shall be radio remote control.


28.6.5, Sheet 13 of 15 Power Supply -Incoming numbers: Employer shall provide two (2) numbers 415 volts, 3 phase, 4 wire supply at operating floor near A-row column

We understand this requirement is for TG hall EOT crane only. For cranes and hoists of all other areas only one no power supply is required.

Confirmed.


28.6.6 , Sheet 14 of 15 HPSV lamps under the bridge. Florescent lamp over the bridge and inside the cabin Requirement may please be reviwed wrt norms for LED type lighting. LED type lighting is acceptable.


28.8.0 , (vi) Sheet 14 of 15 Crane Rails : As per IS : 3443 Grade 50 C 12. Crane rails of grade 55C11 may also be accepted. Availabilty of either grades are subject to availabilty in the market. Hence both the grades should be accepted.

Agreed.

335 Volume IV : Ch-16 : Electricals of Elevator, EOT

16.02.06 iv) (b),Page 14 of 25 The system shall have capability to provide range of 1.5 times the long travel distance of the crane.

For safety reasons range beyond 100 mtrs is not recommended. Please accept. The provision as per bidding specification shall prevail.

Volume IV : Ch-16 : Electricals of Elevator, EOT

16.02.10(i),Page 18 of 25 The operator's cabin shall be steel fabricated open type, suitable for indoor service, and air conditioned,


16.02.10(i) (v) Page 19 of 25 One No Suitably rated window Air conditioner.


16.02.10(i),Page 18 of 25 The operator's cabin shall be steel fabricated open type, ………………….., fire proof construction fire proof construction

For maintenance duty cranes of power plant fire proof construction of cabin is not required. Adequate number of CO2 fire extinguishers shall be provided. Kindly accept.

Confirmed.


16.03.01 (ii),Page 20 of 25 Flexible festoon cable system with supporting rollers & guide rail for power cable and for control cable.

Power supply to electric hoists shall be thru’ PVC shrouded bus bar DSL system. Please note due to space constraints flexible festoon cable system is not ideal and it also affects hook approach of hoist. DSL system is much more compact and cumbersome free system. This is also as per mechanical specification Ch 28, clause 28.6.5 (b)



16.03.04 (ii)Page 22 of 25 Suitable arrangement shall be provided to intimate control room during emergency in the form of audio-visual alarm


16.02.04( 4)Page 12 of 25 Monitoring and signaling in electronic installations, mimic panels.


28.6.2.4 Sheet 10 of 15 Motors shall suit the duty class S4, cyclic duration factor 60% 40% CDF

Confirmed.339

336 As per mechanical specification Ch 28, clause 28.3 (viii), cabin is open type hence air conditioning is not applicable

Cranes and hoists are stand alone equipments meant for erection and maintenance duty & having no bearing in the operation of main plant and its auxiliary systems. Hence interlinking it with control room, Monitoring and signaling, mimic panel are not applicable.

Contradictory requirments have been indicated. For maintenance duty cranes and hoists 40% CDF is standard.

Confirmed.

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16.03.07 (ii) Page 23 of 25 The duty cycle factor for each motor shall not be less than 40%


16.03.07 (i) Page 23 of 25 All motors shall be suitable for 60 starts/hour.


28.6.2.4 Sheet 10 of 15 Motors shall suit the duty class S4, cyclic duration factor 60% and 300 starts per hour

150 starts/hr shall be considered.

Contradictory requirments have been indicated. For maintenance duty cranes and hoists 150 starts per hour is standard.

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343(a) Volume III : Ch 30 : Workshop Equipments

30.3 (21) Sheet 4 of 5 EOT Crane -Reva Customer to note that only one make has been mentioned. It is not possible to place order on a single vendor. As per bidder’s registered vendors list, there are other reputed suppliers who can be considered by customer during detail engineering. Hence for additional sub vendor’s approval, BHEL shall approach to customer separately during contract stage/ detail engineering.Kindly confirm acceptance.

Confirmed.

344 Volume III CHAPTER 37 37.1.5 The scheme & construction details of equipment shall be based on manufacturer’s standard for bipolar design of the Hydrogen plant.

We assume that the referred clause is also applicable for electrical and C&I portion also.


11.1.24 Any other area which contains, Offices, control and instrumentationequipment etc requiring air conditioning will be air conditioned using Packaged/Split AC units with 100 % Standby.

11.3.36(xiii) Precision Packaged AC- 2x100%

11.3.36(xiv) Hi Wall split AC- with 100% standby

11.5.7 Split type Air-Conditioner…………For each premises 100% standby unit shall be provided wherever split AC units are provided in this package.

346 Volume-III 11 11.3.2. (ii) Relative humidity: 50 ± 5% (Max. 60% for areas being air conditioned using Hi-wall split AC)

Kindly note that it is not possible to maintain humidity in the areas conditioned by Split ACs due to below mentioned technical constraints :- 1. There is no provision provided by OEMs for the humidity control in split ACs. 2. Split ACs are fixed capacity equipment, hence it is not possible to control the humidity with split ACs. In view of above technical reasons, requirement of relative humidity may please be dropped wherever AC requirement is being catered through split ACs.Please confirm


11.3.4 A minimum design margin of 10 % shall be considered while sizing AC Plant and related equipment. Solar load, all internal loads due to equipment, lighting, fresh air, occupants etc shall be considered while calculating the heat load.

Volume-III 11 The provision as per bidding specification shall prevail.

Volume-III 11 The provision as per bidding specification shall prevail.

345 As per the standard practice (N+1) configuration of split Acs and package units is provided for each premises , where N is number of working split ACs/Pacakage units & 1 No. standby, to avoid fouling with other equipment’s, facilities within the air conditioned area.

Kindly confirm.

347 Following margins are proposed for effective performance of system: i. 5% & 5% margins on sensible heat & latent heat respectively.

ii. 10 % margin on sizing of AC Plant and related equipment.

Maux(HVAC System)

Maux(H 2 Generation plant)

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11.3.5 Margins for calculating heat load:i. 12.5%, 10% & 10% margins on sensible heat, latent heat & overall heat respectively is to be considered while calculating heat load.

Volume-III 11 11.3.7. Fresh air quantity of 1.5 air change/hour or 35m3/hr/per person or suitable to maintain over pressure of 2 MMWC whichever is higher shall be considered.

Volume-III 11 11.3.13. The Air-conditioning spaces shall be maintained at positive pressure of 2 MMWC to avoid any infiltration of dust.

349 Volume-III 11 11.3.9 Air conditioning system of Chemical Lab shall be designed with 100% fresh air. Cooled & supplied air to AC area shall not be taken back. Exhaust air fans shall also be provided suitably to exhaust the air from Chemical lab.

Considering the cooling load in chemical lab, Split AC's are provided.

Further kindly note that exhaust fans are not provided in chemical lab as fumes are not envisaged.

Customer is requested to accept.


11.1.1 TG Building area and ESP control Buildings:1 x 100% capacity steam powered Vapor Absorption Machines (VAM) as working and 2 x 50% capacity Vapor compression screw/ centrifugal chilling units as standby shall be provided for TG building mainly consisting Central control areas etc.

11.1.3 Service Building:2 x 100% (1W+1S) duty Vapor compression screw/centrifugal chilling units shall be provided for Service Building.

11.4 Chilled Water System Description (For TG, and Service Building)i. 1 x 100% capacity steam powered Vapor Absorption Machines (VAM) as working and 2 x 50% capacity Vapor compression screw/centrifugal chilling units as standby shall be provided for TG building mainly consisting Central control areas & ESP Control Building etc.ii. 2 x 100% (1W+1S) duty Vapor compression screw/centrifugal chilling units shall be provided for Service Building.

11.3.35 Air condition system type selection criteria:i. Estimated heat load more than 60 TR:- Water cooled type Chilled water system with hermetic or semihermetic Screw compressorsii. Estimated heat load range of 30 TR to 60 TR:- Water cooled type condensing units (D-X type) plant with hermetic or semi-hermetic Screw/scroll compressorsiii. Estimated heat load range of 7.6 TR to 30 TR:- Air cooled type Precision packaged AC plant with hermetic scroll compressors.iv. Estimated heat load up to 7.5 TR:- Hi-wall-Split Air conditioners. (TG building area including Central control building & ESP Control Buildings & Service building shall be air conditioned using central chilled water system as specified elsewhere).

33 33.4 (36) Separate A/C systems shall be provided for Main plant, ESP Control Room & Service building. For further details relevant section of Technical Specifications may be referred.

11 11.5.1 (II) Condensing Unit Compressor Type : For condensing units of ESP/VFD control rooms shall be Hermetically sealed Screw/scroll type operating on R134a/R407C refrigerant complete with accessories and automatic control facilities


Volume-III Bidder understanding is same as Tender Specification.

g g q p


348 1.5 air change/hour or 35m3/hr/per person whichever is higher shall be considered for arriving at fresh air quantity and same has no relation with positive pressure to be maintained.

However sufficient positive pressure shall be maintained in Air-conditioning spaces through AHU.


350 11 There is ambiquity in different clauses of specification, However We understand the following: 1. 1 x 100% capacity steam powered Vapor Absorption Machines (VAM) as working and 2 x 50% capacity Vapor compression screw/centrifugal chilling units as standby shall be provided for TG building & ESP Control Building.

2. 2 x 100% (1W+1S) duty Vapor compression screw/centrifugal chilling units shall be provided for Service Building.

3. 2 x 100% (1W+1S) duty Water cooled DX system with Vapor compression screw compressor shall be provided for FGD control building.

4. For other Areas, Air condition system type selection criteria as per clause no. 11.3.35, Chapter 11 of specification shall be followed.

Please Confirm.

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6 6.1.13 Air Conditioning and Ventilation SystemFGD Control Room, Elevator Machine Room and Analyser Room (if applicable) shall be provided with air conditioning system. The air conditioning system for each area shall consist of split type airconditioners with standby of minimum one number or 25% of the population, whichever is high.

11 11.1.2 FGD control building2 x 100% (1W+1S) duty Water cooled DX system with Vapor compression screw compressor shall be provided for FGD control building.

351 Volume-III 11 11.3.36. Redundancy of Equipments: ix) Chilled Water AHU-TG Building - One AHU as standby of similar area capacity (per AHU room) x) Chilled Water AHU (Other Area)- Multiple AHU of similar capacity per AHU room.

a) TG Building AHU : Common standby i.e., one no standby AHU shall be provided in power house wherever AHU is envisaged.

b) ESP control building : Common standby i.e., one no standby AHU may please be considered seeing criticality of control room.

c) For balance area: Multiple AHU shall be provided as per specification without standby.


Bidder understanding is same as Tender Specification.

11.5.9 Fresh Air Unit for Air Conditioning systemThe fresh air unit shall consist of:...................Pre-filter made up of HDPE and efficiency 90% down to 10 microns and maximum face velocity of 2.25 m/sec.Fine filter made up of HDPE and efficiency 99.5% down to 3 micronsand maximum face velocity 2.25 m/sec.

11.5.4 Air Filters i) Pre Filter 4) Efficiency : Average arrestance of 65 - 80 % when tested in accordance with BS: 6540/ASHRAE – 52 - 76. ii) Fine Filters (Microvee type) 4) Efficiency : Average arrestance of 80-90% when tested in accordance with BS 6540/ ASHRAE 52 7611.3.11. First 6 meters of supply air duct from AHU air outlet shall be acoustically insulated with 25 mm thick fiberglass crown 150 of density 48 kg/m3 and shall be covered with 26G aluminum perforated sheet. Perforation area shall be 30% of free area.

11.10.4 Acoustic Insulationa) All ducts up to a distance of 5 m from AHU shall be acoustically lined from inside with 25 mm thk resin bonded glass wool of 48 kg/ cum density with 30 gauge perforated Aluminium sheet having 5 mm dia perforation at 8 to 10 mm centre to centre distance. Insulation shall be fixed on wooden frame of 600 x 600 mm dimension.b) Fibre glass tissue sheet shall be applied over the outer surface of insulation before applying perforated Aluminium sheet. Application of acoustic insulation shall be in line with requirements specified above.

Volume-III 11 Follow clause 11.5.9 for filters used in Fresh Air Fan Unit.

Volume-III 11 The provision as per bidding specification clause 11.10.4 shall prevail.

352 Specification of filters is diffent in both the clauses. However, We propose to consider the filters as per clause no 11.5.4, Chapter 11, Vol III of Technical specification for fresh air unit.


353 Type of Material and required length of ducts to apply accoustic insulation is different in both clauses.

However, We propose to consider the acoustic insulation as per clause no 11.10.4, Chapter 11, Vol III of Technical specification.


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354 Volume-III 11 11.3.1. Ambient Dry bulb temperature: 46.6 degree C. For other details of ambient conditions, refer published documents for meteorological data for Plant site.

As per the publised document of IMD attached under Chapter 2: Project information of specification, highest temerature during the year is 42.2 degree C. We propose to design the HVAC system as per refered IMD document or customer is requested to furnish the following complete design conditions wrt Ambient Dry bulb temperature of 46.6 degree C.: DBT & WBT/RH during summer, monsoon and winter.


PAGE 46 OF 75




12.2.7 Duct Design Criteria – Velocity shall be 12 m/sec (max.) for main duct, 9.0m/sec. (max.) for branch duct and 5.0 m/sec. for the grills.

12.2.11 Air distribution system shall be sized to have a constant frictional drop along its length and air velocity through ducts shall not exceed 12.5 m/s.

356 Volume-III 12 12.2.15 Specific Requirements (ii) For switchgear and cable vault rooms other than being served by AWU/UAF, the supply air shall be filtered and distributed throughair distribution system by means of Centrifugal fan filter unit, ducting & grills. The hot air shall be exhausted through wall mounted gravity operated dampers to maintain an over pressure of 2-3 mm positive pressure to prevent the ingress of dust into theroom from outside. In case the estimated requirement of an area is less than 15000 CMH, the Tube Axial fan filter unit can be supplied.

As a general practice in power plant wherever wet ventilation is not provided, dry ventilation through tube axial fans is provided, irrespective of the air volume requirement.

Please accept.


357 Volume-III 12 12.2.3 Inside dry bulb temperature shall be minimum 5 degree C below the design ambient dry Bulb temperature during summer for evaporative cooled areas.

Inside dry bulb Temperature shall be maximum 3 degree C above the design ambient dry Bulb temperature during summer for mechanically ventilated areas.

As a general practice in power plant "Inside dry bulb temperature shall be minimum 3 degree C below the design ambient dry Bulb temperature during summer for evaporative cooled areas" is maintained.

Please accept.


358 Volume III Mechanical Works, Ch-30

,Workshop Equipment, page no. 2 of 5, clause no. 30.3.

Workshop Equipment.

Make of the machines / equipment.

Customer to note that only one make for machines has been mentioned in the tender specification. However, it is not possible to place order on a single vendor. Hence for additional sub vendor’s approval for various equipment’s, BHEL shall approach to customer separately during contract stage/ detail engineering.Kindly confirm acceptance

Agreed.

1 IV 14 14.16.04 At no stage, speed switch shall be provided to achieve requirementsmentioned in Clause No. 14.0114.01 to 14.0114.03

Whether speed switch will be allowed in case of high inertia loads(ID fan motor, Mill motor etc.) to design motor with optimum performance ?

ONLY IN CASE OF HIGH INERTIA DRIVES LIKE FAN DRIVES, SPEED SWITCH IS ACCEPTABLE.

2 IV 14 14.12.02 Pump motor subject to reverse rotation shall be designed to withstand the stresses encountered when starting with non-energized shaft rotating at 125% rated speed in reverse direction

Whether Pump motor is envisaged for starting under reverse rotation ? Generally power plant motors are envisaged for starting in forward direction.

Motor shall start from standstill condition. Reverse rotation if any shall be prevented mechanically.

Ventilation system

355 Maximum velocity of duct is diffent in both the clauses. However, We propose to consider the Main duct velocity as per clause no 12.2.7, Chapter 12, Vol III of Technical specification . Customer is requested to accept.

Maux(Workshop Equipment)

Volume-III 12 The provision as per bidding specificatrion clause 12.2.7 shall prevail.

B. HT MOTORS

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3 IV 14 14.17.04 The value of the polarization index for motors above 160kW should not beless than 2 when determined according to IS: 78114.0

Applicable standards for PI Mesaurement is IEC:60034-27 Part 4. Does not the above standard hold good for PI Measurements ?

IS to be followed. The provision as per bidding specificaton shall prevail.

4 IV 14 14.27.06 When pressure oiling is required for horizontal motors, bearings shall besleeve type arranged for pressure oiling supplied from lubrication system ofdriven machine, with ring oiling for starting and emergency duty. Ringoiling system shall be adequate for starting and continuous operation ofmotor for at least half an hour, without pressure oiling system in operation.

Motors with Forced Oil Lubricated sleeve bearings are with Oil Ring for emergency duty. The ring oil lubrication is for motor starting andcoasting down period only. The running of motor without FOL would risk thebearing life, which should not be allowed for critical motors of power plant.The same to be taken up with customer for resolution.

Agreed for bidder's proposal.

5 IV 14 14.40.00 bearing temperature indicators and shall have two (2) sets of contacts, each set having 2 NO + 2 NC contacts

Whether Bearing DTTs are utilized for alarm and trip of motor ?Generally alarm and trip is initiated by Bearing RTDs and not be DTTs. DTTs are for local temperature indication only.

Alarm & trip is generated from RTDS only. However, Bidder to follow bidding specification for supply of TI with 2 sets of NO+NC contacts

1

II Ch 8 : Functional Guarantee &Liquidated Damages

xv) Solar PV cell capacity testMonthly performance ratio for solar voltaic project shall be guaranteed asindicated below:The performance Guarantee (PG) Test shall be carried out after successfulcommissioning of all solar rooftop locations. PG Test shall be carried outon any rooftop location by measuring Performance Ratio (PR) andcomparing to the Guaranteed PR. The test shall be repeated for eachlocation having different type of inverter.The mathematical formula for calculating PR is given below:

(%) = ( ℎ) 100

Installed capacity (KWp) (ℎ

2)For the purpose of measuring Global Inclined Insolation (GII), pyrometershall be installed by the Contractor.

We suggest performance ratio to be guaranteed on annual basis, as per standard procedure.

Agreed. Performance ratio shall be guaranteed on average annual basis.

2

II Ch 8 : Functional Guarantee &Liquidated Damages

x) Shortfall in guaranteedmonthly performance ratioof solar photo voltaic (PV)Project.To be calculated as per clause3 1 (xiii) in this section

We suggest performance ratio to be guaranteed on annual basis, as per standard procedure. Agreed. Performance

ratio shall be guaranteed on average annual basis.

3

III Solar Roof Top System

36.1.1 List of buildings identified for installation of rooftop solar system are asfollows:

For the given buildings we shall propose the rooftop solar capacity in the bidding stage as per the roof sizes Agreed. However,

capacity shall be on actual based on the list of building as 1000 kW whichever is higher.

C. ROOFTOP SOLAR

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4

III Solar Roof Top System

36.1.2 Operation and maintenance (O&M) of the plants for a period of one yearfrom the date of successful completion of plant performance guaranteetest. During this period, the bidder shall be responsible for supply of allspare parts as required from time to time for schedule and preventivemaintence, major overhauling of the plant, replacement of allequipments in the plant including defective PV modules, inverters,transformers etc. and maintaining log sheets for operation detail,deployment of staff for continuous operations and qualified engineer for supervision of O&M work, complaint logging and its attending. All PVmodules shall be cleaned regularly and washed atleast once in a week.

No manpower is envisaged to be deployed for O&M of solar power plant

Man power shall be deployed for O&M.

5

II General & Schedules Ch 1 : Intent of Specification-Sheet 7 of 12

1500kW Solar PV Plants on Roof Tops In Vol-III capacity is 1000kW. Please confirm

The minimum capacity shall be 1000 kW.

1 II Ch-2 Appendix – II: Coal Quality Parameters

PROXIMATE ANALYSISULTIMATE ANALYSISGCVAsh Fusion TemperatureAsh Analysis

1. Customer to clarify whether given coal analyses are as "Air Dried" basis or "As received" basis. If it is "air dried" basis, kindly furnish Total moisture value.2. Summation of provided ultimate analysis (if assumed as dry ash free basis) does not adding to 100%. It is 100.35%, 92.46% and 109.4% for Design, Worst and Best coal respectively. Kindly provide the ultimate analysis including GCV on as received basis.3. Kindly confirm whether furnished Ash fusion range is "Under reducing atmosphere". 4. Content of trace elements in ppm for Chlorine, Fluorine, Lead, Zinc, Arsenic, Cadmium, Chromium and Mercury, if any to be mentioned in ultimate analysis of coal. HCl and HF content in Flue gas has got implication on Limestone consumption, Recirculation flow rate and waste water quantity in FGD system.Lead, Zinc, Arsenic, Cadmium, and Chromium are considered to poisonous to SCR catalyst. This will have adverse effect on catalyst life and efficiency.

Revised coal analysis shall be provided ithrough amendement.

2 III

III

Sec-1/Ch-1

Sec-2/Ch-1

1.1.15.3 (i)

2.10.5.2 (1)

Minimum Eight (8) no’s of coal pulverizers shall be provided for each steam generator.

Adequate to achieve 100% TMCR for all specified coal(s) and all operating conditions but not less than eight (8) mills.

Minimum Seven (7) no’s of coal pulverizers shall be provided for each steam generator. Kindly confirm.


3 III Sec-2/Ch-1 2.1.24 (iv) The working fluid temperature to be considered for design of boiler tubes, headers, separators and other pressure parts upto first stage of attemperation shall be arrived by adding an additional margin of minimum 40 deg.C to the maximum predicted/expected fluid temperature in these pressure parts or plus the margin as per IBR whichever is higher.

The existing clause shall be modified as:The working fluid temperature to be considered for design of boiler tubes, headers from waterwall inlet to waterwall outlet shall be arrived by adding an additional margin of minimum 40 deg.C to the maximum predicted/expected fluid temperature in these pressure parts or plus the margin as per IBR whichever is higher.Kindly Confirm.


D. SG AREA

PAGE 49 OF 75




4 III Sec-2/Ch-1 2.21.23 (13) Cyclone Separator shall be installed in the flue gas duct after economizer …. Since LPA (Large Particle Ash) screen is used to collect large ash particles,Cyclone Separator is not required and hence not envisaged. Accordingly relevant clauses and its reference elsewhere in the tender specification and tender drawing including ID Fan selection and guarantee schedule may be deleted.

Agreed

5 II

III

Ch-8

Sec-2/Ch-1

4.1.1

2.1.17.1

Contractor shall guarantee that maximum total NOx emission from the unit shall not be more than 100 grams of NOx (from thermal as well as fuel) per giga joule of heat input (at 6% O2 level and as per equivalent NO2)

Combustion system along with wind box, air ducting and other associated parts shall be designed for guaranteed maximum NOx emission of 100 mg/Nm3 at 6% O2 on dry gas basis at Selective Catalytic Reduction (SCR) outlet.

Design will meet guaranteed maximum NOx emission of 100 mg/Nm3 at 6% O2 on dry gas basis at Selective Catalytic Reduction (SCR) outlet. Kindly Confirm. Agreed. Design shall

meet guaranteed maximum NOx emission of 100 mg/Nm3 at 6% O2 on dry gas basis at Selective Catalytic Reduction (SCR) outlet

6 I Attachment- 8 (Demonstration Parameters/ Capabilities)

Refered clauses have not been found.

7 III 2.7 2.7.2 (1.g) The first bank of coils in the second pass (in case of two pass boiler)shall be located at least 2 meters below from the second pass gas entryzone to minimise erosion.

It is bidder practise to align the top of horizontal coil in second pass with the work point of extended pass and hadn't faced erosion issues. Moreover, Bidder provides Erosion Shield and cassettes baffles wherever applicable to minimise erosion. Hence, the first bank of coils in the second pass (in case of two pass boiler) shall be located aligning the work point of the second pass gas entryzone Kindly confirm


III Sec-2/Ch-1 2.13.1.2.iii For flue gas ducts downstream of ESP, additional fly ash loading on the surface or for one tenth of duct full of ash or for maximum possible accumulation of ash in the ductwork, under all normal, upset or abnormal operating conditions, whichever is higher.

III Ch-6 6.4.1.2.3 All ducts to be designed for one tenth of duct full of ash.9 III Sec-2/Ch-1 2.13.1.5.i Minimum 8 mm thick steel plates for gas ducts from APH outlet to ESP inlet and 6 mm

after ESP.Bidder proposes the use of 6 mm thick steel plates for all gas ducts. Kindly Confirm. The provision as per

bidding specification shall prevail.

10 III Ch-6 6.4.1.5.d Lining/cladding/wallpaper of 2 mm (minimum) thickness of alloy 276/Alloy-59 or better material in downstream of Absorber up to chimney inlet duct.

Bidder proposes to also include Titanium (Grade 2) material for lining/cladding. Accordingly clause may be modified as:Lining/cladding/wallpaper of 2 mm (minimum) thickness of alloy 276/Alloy-59/Titanium (Grade 2) or better material in downstream of Absorber up to chimney inlet duct.Kindly confirm.


11 III Ch-6 6.4.1.5.e The duct from Absorber outlet to bypass duct shall be made of Carbon steel of minimum 7mm thickness with 2 mm (minimum) thickness lining/cladding/wallpaper of 2 mm(minimum)thickness ofalloy 276/ Alloy-59 or better material.

Bidder proposes to also include Titanium (Grade 2) material for lining/cladding. Accordingly clause may be modified as:The duct from Absorber outlet to bypass duct shall be made of Carbon steel of minimum 7mm thickness with 2 mm (minimum) thickness lining/cladding/wallpaper of 2 mm(minimum)thickness ofalloy 276/ Alloy-59/Titanium (Grade 2) or better material.Kindly confirm.


V Part A 4.00.00 (f) Type of Instruments :-For sequence, protection, control and alarm circuits, electronictransmitters, temperature elements with temperature transmitters etc.are to be provided.

V Part A 4.00.00 -Notes- Sl No:7 Level switches / pressure switches / flow switches/ any other process switch etc. for OLCS / Alarms / Interlocks / Protection. Pressure switches at inlet, outlet of individual pumps and discharge header of pumps for protection and auto start / stop & alarms shall be provided.

8 Bidder will consider 1 ft of ash in the duct after ESP, since after ESP the ash accumulation in the duct is minimal. Kindly Confirm.


12 It is clarified that, inline with Cl Cl-4.00.00 (f)-Vol:Part A-Sheet 11 of 100, process transmitters (pressure, DP, flow, level) & temperature elements with temperature transmitters are envisaged for trip, interlock & alarm purposes.

Kindly confirm

PAGE 50 OF 75




V Part A 4.00.00 -Notes- Sl No:16 Process switches like pressure switch, level switch etc. shall be provided with triple redundancy for all the applications required for Trip & protection of HT drives, boiler… whose non-availability may lead to loss of generation.

v APPENDIX - V TO PART – A, MINIMUMREQUIREMENTS FOR FIELD INSTRUMENTS

2.00.00 (ii) (j) Pressure Switches:Pressure switches/any other process switch etc. for OLCS / Alarms / Interlocks / Protection. Pressure switches at inlet, outlet of individual pumps and discharge header of pumps for protection and auto start / stop & alarms.


2.00.00 (iv) (d) Pressure Transmitters as on required basis for monitoring, interlocks & controls as per redundancy criteria and approved by owner.


3.00.00 (v) Temperature Measurements:-Adequate number of temperature Elements shall be furnished to provide initiating contacts for temperature interlocking and trip circuits


4.00.00 Level Measurement:Level switches for OLCS / Alarms / Interlocks / Protection. Level switches for sump/ tank level high/ normal/ low/ very low interlocks.

III Ch 1 1.1.18 (14) Fuel Oil System:Supply of one (1) no. flow meter of positive displacement type including all its accessories.

V Part B/ Ch 2 2.12.04 POSITIVE DISPLACEMENT TYPE FLOW TRANSMITTERSThe Bidder shall provide positive displacement type flow transmitters for fuel oil flow measurement, suitable for the fuel oil being used for the project…

V Part A 5.00.00 (j) HFO/LDO flow meters shall be based on coriolis mass flow technology.

III Ch 1/ Section 2 2.11.3 (VII) Trip and Nozzle ValvesLight oil trip valves &individual burner nozzle valve solenoid shall be:(i) Of single coil heavy duty construction having class 'H' insulation.(iii) De-energized/air fail to close type.(iv) Designed for operating voltages as under:(a) Trip valve solenoid 24 Volts DC(b) Nozzle valves solenoid 24 Volts DC

V Part B/ Ch 2 2.14.00 f. For operation of the fuel oil corner nozzle valves, fuel oil trip valves etc., double coil solenoid valve ( latch coil & relatch coil) shall be adopted.Single coil usage requires always power and loss of power leads to closure of above valves resulting the unit trip or loss of generation.j. Solenoid valve shall operate on 24 V DC, UPS 230 V AC or 220 V DC as per system requirements.

III Ch 1/ Section 1 1.1.7.2 (vii) Each leg of each stage of desuperheating spray system for superheater shall be provided with the following: vii) Welded type attemperation water flow nozzle before/ after spraycontrol valve in the common line along with all accessories for flow measurements and controls.


13 It is clarified that, as per Cl.5.00.00 (j)-Vol V-Part A, Coriolis mass flow meter is provided for fuel oil flow measurement. Kindly confirm Bidder understanding

is correct .Bidder to note that the service and quantity for Fuel oil measurements shall be in line with the contract only.

14 It is clarified that, in line with Cl 2.14.00-Vol V-Part C/Ch 2, double coil solenoid valves are provided for fuel oil trip valves & corner nozzle valves. As per standard philosophy followed for all contracts, Fuel oil trip valves are 220 V DC operated & corner nozzle valves are 240 V AC operated.

Kindly confirmConfirmed . However, the type of power supply to the Solenoid valves shall be decided during detailed engineering stage.

15.00 It is clarified that inline with cl 1.1.7.2 (vii) & 1.1.7.3 (vii)- Vol III-Ch 1/ Section 1, Flow Nozzle is envisaged for Superheater & Reheater spray flow measurement.Kindly confirm.

Bidder clarification Agreed However the

PAGE 51 OF 75




III Ch 1/ Section 1 1.1.7.3 (vii) Each leg of reheater desuperheating spray water system shall be provided with the following: vii) Welded type attemperation water flow nozzle before/ after spray control valve in the common line along with all accessories for flow measurements/ controls

V Part A 5.00.00 (f) Flow Measurements:-l) Orifices shall be provided for following services:-i) SH & RH Spray water flow measurement with triple redundant Flow Transmitters.

16 III Sec-2/Ch-1 2.7.2 (10 (b)) Additional space of atleast 5% for SH and RH coils area shall envisaged. Additional space of 5% of convective area of SH and RH coils will be provided. Kindly confirm.

17 III Sec-2/Ch-1 2.3.1-l) Design of Boiler and its supporting structure shall be considering 50% ash/clinker loading in furnace bottom hopper and corresponding to ash density of 1600 Kg/m3.Further load cells (16 min.no of load cells per boiler) shall be installed in the furnace roof enclosure to give indication of ash build up in the furnace bottom hopper.

Ash accumulation in the spiral furnace hopper is not recommended.For supercritical boilers with spiral wall construction, the tubes are almost horizontal and ash accumulation is to be avoided to protect the panel tubes from deformation. However, for design of Boiler and its supporting structure 1/3rd ash/clinker loading in furnace bottom hopper and corresponding to ash density of 1600 Kg/m3 will be considered. KIndly confirm.

18 III Sec-2/Ch-1 2.7.2.4-a) All horizontal heat transfer surfaces shall be supported by steam or water cooled hanger tubes designed for a minimum of 2 times the calculated load so as not to cause any dislocation/damage to the tubebanks/sections. Necessary calculations in support of this shall be furnished by the bidder. The stress in the hanger tubes under such condition also shall not exceed the maximum permissible limits as perIBR. One (1) mm erosion allowance shall be provided over and above the calculated thickness of hanger tubes.

Mechanical strap supports for Economiser coils and Water cooled hangers for Horizontal SH/RH coils are envisaged.

Prolonged operation with even one failed hanger tubes is not advisable and hence failure of 50% of hanger tubes is not considered in design

19 III Sec-2/Ch-1 2.4-i) b) The casing/pent house and its supporting system shall be capable of taking additional loads due to accumulations of ash upto 300 mm height or actual expected (in between two overhauls of the unit),whichever is higher. This additional load is over and above other loads considered for casing design. The ash density for the purpose of ash loading shall be at least 1350 kg/m³.

The roof panel for supercritical boilers is fin welded panel, thus the chance for ash ingress is very minimum.Hence, the additional load due to accumulation of ash upto 300mm height, over & above the other loads, shall not be considered. Kindly confirm

20 III Sec-2/Ch-1 2.11.3 IV Note: A suitable interconnection along with isolation valves shall be provided in the common fuel oil header outside the fuel oil pump house for taking tap off for future unit. The piping system including valves upto the tap off shall be sized considering continuous operation all the three LDO pumps at their ratedcapacity

Piping and in common fuel oil pump house area is designed for two boiler requirement as all the equipment are sized for the two steam generators requirement as per the specification/tender. However, 3 LDO pumps will be provided. Kindly confirm.

21 III Sec-2/Ch-1 2.11.3 XIII (iv) Instrument root valves on LDO lines shall be of 40 NB size, flanged OS & Ytype, with body rating in ASA as per process condition.

Instrument line sizes will be of NB15 for LDO lines with isolation valves as the pressure envisaged in fuel oil system is less than or equal to 25 kg/sq.cm. Kindly confirm


Agreed . However, the quantity and location of the flow elements shall be decided during detailed engineering stage.

PAGE 52 OF 75




1 Volume-III Sec-4/Ch-1Sheet 2 of 5

4.1.1.1 One(1) number outdoor installation type, natural circulation, single / bi-drum, pressurized furnace, water tube boiler suitable for firing LDO and having steaming capacity not less than 90 T/hr (Excluding steam requirement of Auxiliary Boiler) with steam parameters at superheater outlet as optimized by the bidder maintaining a minimum 50 deg. C superheat and minimum temperature of 250 deg. C taking care of various start up requirements including cold, warm and hot start up conditions. Output steam of the auxiliary boiler shall be connected to the station header.

Auxiliary boiler will be in operation only during the start-up of the main boiler. Steam produced from Aux boiler will be used for the following purposes:1. De-aerator pegging2. Turbine gland sealing3. Feeding SCAPH etc.From our experience it has been observed that the cumulative sum of all the above requirements during start-up will be less than 75 T/hr. Therefore an auxiliary boiler of 75TPH capacity and Super heater outlet temperature of 290°C shall be offered.Kindly concur.



4.1.1.1 The boiler outlet flue gas temperature shall not more than 180 Deg C and sulphur dew point temperature of flue gas whichever is less.

Auxiliary boiler will be in operation for a period of (10-12) hrs or lesser during the start up of the main boiler. Boiler Flue Gas Temp. of 180°C is possible only by installing an APH and an economiser. Aux. Boiler is a package boiler and its design has been standardized with feed water being directly admitted into the drum without involving Economizer, similarly air is being directly admitted through the FD Fan & burner, eliminating APH. This arrangement makes the aux boiler compact and eliminates any unwarranted material addition, increase in FD Fan aux. power consumption. The Boiler Outlet Flue Gas Temperature for BHEL's standard package boiler will be around 350°C.All the auxiliary boilers supplied by BHEL are able to efficiently suffice the auxiliary steam requirement of the corresponding units. Hence, the amount of savings obtained by going for a a less value of Boiler Outlet Flue Gas Temp. will be negated by the high capital and maintenance cost. Hence, a compact auxiliary boiler as per BHEL's proven design shall be supplied.



4.1.11 Aux Boiler Canopy:To offer protection to the Boiler against rainfall, a rain canopy shall beprovided covering all operating areas and over all equipment. This shall bemade from steel frames, supports and steel sheathing and shall be completewith guttering & down pipe, etc. as necessary.

Canopy shall be provided on the floors & platforms where instrumentation/ equipment is present (like drum floor, burner floor), inline with BHEL's standard practice.Kindly concur. Agreed with the

bidder's proposal.


4.1.17 Equipment Handling Arrangement Since all the associated equipment are of smaller size, separate equipment handling system is not provided for Aux. Boiler as per our standard practice.Kindly concur.

If wt. is more than 2 Tonne, equipment handling arrangement is to be provided.


4.1.1.4 The steam temperature control range of Auxiliary boiler shall be from (atleast) 40% to 110% BMCR. During this range, the superheated steamtemperature should remain at rated value.

Steam Temperature control range of Aux Boiler shall be (60-110)%BMCR.Kindly concur.



2.11.3.XIII Fuel Oil Preparation and Firing System:Valves shall conform to following requirements:a) Type of valves (for oil services):Plug type (metallic seated), leak proof,fire safe as per the requirement of API6FA

For auxiliary boiler, considering its intermittent operation i.e. only during the start up of main boiler, Gate and Globe valves shall be used for isolation and regulating purpose respectively in-line with earlier contracts executed by BHEL.


7 - - - Aux. Boiler Instrumentation & Control Auxiliary boiler is a package boiler and shall be in service only during the start up of the main boiler. Considering its intermittent operation, the instrumentation & controls have been minimized/ optimized and standardized ensuring safety of the aux. boiler. Hence, kindly confirm that the instrumentation & controls for aux. boiler shall be

as per bidder’s standard practice


F. Valves

E. Auxiliary BOILER

PAGE 53 OF 75




1 II 9 22(a) HP bypass control valve completeAssembly – 1 set

We understand that 1 set means 1 No. of HP bypass Control valve complete assembly. Please confirm. Confirmed.

2 II 9 22(b) HP bypass control valve servomotorcomplete assembly – 1 set

We understand that 1 set means 1 No. of HP bypass Control valve servomotor complete assembly. Please confirm. Confirmed.

3 II 9 22(c) Spray Water injection valve for HPbypass system complete assembly– 1 set

We understand that 1 set means 1 No. of Spray Water injection valve. Please confirm. Confirmed.

4 II 9 22 (d) to (k)

d. Control fluid pump including motor and complete couplinge. Turbine cylinder drain valvesf. Tube nest assembly vacuum pump coolerg. Deaerator safety Valvesh. Vacuum Breaker valve completei. Electro hydraulic converter assembly of main turbine governing system.j. Electro hydraulic converter assembly of LPBP.k. Extraction bellows/compensatorassemblies for all the turbine extraction lines

Though these items are included under HP bypass system, we understand that these items are not related to HP Bypass system. Please confirm.

Agreed. However, provided in mandatory spares.

5 II 9 (D)

i) Feedback transmitter 2 NOS.ii) Electronic positioner 2 NOS.iii) Proportional Valve 2 NOS.iv) Quick opening device 2 NOS.v) Seal sets 4 Setsvi) Solenoid Valves 2 NOS.vii) Filters for Oil Units 1 setviii) Supply manifold for oil units 1 Noix) Hose for each service 1 eachx) Seal set for oil unit 1 Setxi) Complete actuator for eachtype and model - 1 set

For SNos. (i) to (iii), our understanding is that 1 No. each of the items for HP bypass valve and 1 No. each of the items for Spray control valves need to be offered. Please confirm.S.No. (iv) is not applicable for spray control valves of the HP bypass system.S.No. (v) – Our understanding is that the seal set against this item should include the seal sets of Actuators, Proportional valves, Quick opening devices. 1 set shall include the seals for 1 No. of each of these items. Please confirm.S.Nos. (vii) to (x) – Since the oil supply unit is common for HP bypass valves and Spray control valves of HP bypass system, these items cannot be offered separately for HP bypass and spray control valves. S.No. (xi) – 1 set shall consist of 1 No. of each type and model of actuator of HP bypass valve and spray control valve. Please confirm.


6 IV Chapters 1 & 14 1.27.02 of Page 49 and 14.14.01 of Page 330

All LV motors rated 0.37kW and higher with S1 duty shall compulsorily be of energy efficiency level IE3 as per IS 12615:2011.And Continuous duty LT motors rated above 0.37kW upto 160 KW Output rating (at 50 deg. C ambient temperature), shall be Efficiency class-IE2, conforming to IS 12615, or IEC:60034-30.

Energy efficiency levels of motors above 0.37kW upto 160kW rating is stated as IE-3 and IE-2 in different locations of the document. Please confirm the Energy efficiency level to be followed for these motors.

IE-3 is to be followeed for energy efficiency level.

7 V Part B Chapter 11 11.04.00 (5) Body Material of HP bypass control valve – SA182 F92 DDE to suit process parametersThe provision as per bidding specification shall prevail.

8 V Part B Chapter 11 11.04.02

1. Material of HP Bypass steam conditioning valve internals should be as under or better:Guide : X20CrMoV121.Plug/stem : X20CrMoV121.Seat ring : X20CrMoV121.2. NOTE : Valve body rating shall meet the process pressure and temperature requirement as per ANSI B16.34.3. Cage material may be different from Trim/Plug material subject tosuperiority of cage material than trim/plug material.

1. Materials of internals will be based on proven designs inline with the provenness clause of the tender. 2. Design of HP bypass steam conditioning valve body is influenced by the thermal transients. So, providing wall thickness to meet the requirements of ANSI B16.34 will make the valve body more susceptible to cracks due to thermal stresses. Hence, valve body will be designed inline with the design practices for proven designs.3. Refer 1 above.


9 V Part B Chapter 13 Control Valves – Cv testHP bypass system suppliers do not provide Cv test reports. Instead they submit CFD test reports. Hence, for HP bypass system valves, CFD test reports may also be accepted in lieu of Cv test.


10 IV Chapter 15 15.06.03

Each motor actuator shall have Six (6) rotary drum position limit switches with two for open each with 2 NO + 2NC contacts and two for close each with 2 NO + 2 NC contacts positions, each with adjustable setting between fully open and fully closed positions. Each rotary drum limit switch shall have two (2) limit switches for intermediate open position each with 2 NO + 2 NC contacts.

We are providing 4 position limit switches, 2 for open and 2 for close. Since all the 4 limit switches(2NO+2NC) can be set to any position in between open & close. For all our projects we are providing 4 Limit switches with 2 NO+2NC contacts as standard.


11 IV Chapter 15 15.06.02 viii) Motor shall be designed to close in 30 secs from full openposition and shall have adequate capacity to open and close under full unbalanced design pressure.

For higher size valve operating time will be 60-90 seconds.The provision as per bidding specification shall prevail.

12 III Chapter 26 26.7 E) 5.3 Seat bushing: Renewable type screwed on and held in position by pinFor power cycle piping application, safety valve seat bushing shall be of welded type and this construction has proven performance record in all BHEL supplied boilers

Agreed.

PAGE 54 OF 75




13 III Chapter 26 26.7 E)6.5 Spring:Alloy steel Safety Valves – SS or Tungsten steelCarbon steel Safety Valves – Carbon Steel

We will comply to Tungsten steel and carbon steel springs as per tender requirements. For applications where temperature is <570°C, Springs shall be made of Chromium alloy steel material, which has proven performance record in all BHEL supplied boilers.


1 III - Mechanical Works

14 - Laboratory Equipment 14.2 - 14.8 Make for most of the Equipments, Glasswares, Chemicals have been provided

Procurement through BHEL registered vendors for these equipments, Glasswares and Chemicals be permitted for procurement in a lot so that after sales services can be co-ordinated by end user smoothly.

Makes proposed by bidders shall be subject to approval during detailed engineering.

2 III - Mechanical Works

14 - Laboratory Equipment 14.5.1 Electrical Anemograph Electrical Anemograph is now-a-days outdated and difficult to procure. Electrical

Anemometer is proposed in place of electrical anemograph. Agreed.

3 V - Instrumentation & Control Works

Part - B Chapter 15 Environment

Monitoring Systems15.02.03 - 15.03.05 Ambient Air Quality Monitoring Systems (AAQMS) Quantity and Parameters to be

monitored

Only 04 Nos. AAQMS for the parameters as indicated in 15.02.04 (a. to i.) would be supplied. Any additional AAQMS Station and Analysers for additional parameters would have additional financial implication.

Bidder to confirm compliance to Specification clause 15.02.02 & 15.02.05. No additional cost is payable/applicable due to additional locations , if decided during detailed engineering stage.

Civil Building with electrical work, furniture, water supply line, refrigerator,freezer, storage almirah, air conditioning etc shall be included in the scope

1 Vol-II ch-4 4.3.2 Provenness for CWP: DJU Condition BHEL seeks qualification through clause 4.3.2 of Provenness criteria for manufacturing CWPs for this project. BHEL is a proven equipment manufacturer of CWPs and has a valid technical licensing agreement for manufacturing CWPs of 660/700/800 MW super-critical power plants. (Hence, customer may kindly consider waiving off the requirement of JDU and bank guarantee by our collaborator.)


2 Vol-III Sec-2,Ch-2 7.3.1 (XVI) TDH per stage for the main pump shall not exceed 670 mwc. For the higher cycle parameters, the per stage head will be more that 670 mwc. As per NTPC latest specification for 660/800 MW, the specification calls for per stage average head not to exceed 800 m at design point.Customer is requested to ammend as per NTPC Specification

Agreed.

Note:- Any additional requirement of chemical laboratory like civil building, electrical work, furniture, water supply line, refrigerator,freezer, storage almirah, air conditioning etc. is not considered in our estimates.

G. LAB EQUIPMENTS

H. PUMPS & MILLS

PAGE 55 OF 75




3 Vol-III Ch-15 15.11 PERFORMANCE GUARANTEE TESTS:After the manufacture, all the CW pumps shall be performance tested at the manufacturer’s works to determine the power consumption and the head capacity characteristic.

We propose to conduct Model Test at manufacturer's works and performance of full pump will be derived from Model testing.Performance test of full pump/proto type will be conducted at site instead of Manufacturer's works.

Agreed.All the routine/type test to be performed at shop.

1 III-MECHANICAL

Ch 1: SG & AuxiliariesSection 2 : Design Basis ofSG & Auxiliaries and SCR

2.9.2(ii) ;SHEET 32 of 120

Condensate from SCAPH shall be led to atmospheric flash tank throughSCAPH drain collection tank(s). SCAPH condensate collection tank(s)shall be pressurized so that drain can go to Atmospheric flash tank.Alternatively Atmospheric SCAPH drain collection tank(s) with properpumping arrangement (3x50%) with necessary valves etc. shall beprovided.

In once through boilers, SCAPH drains along with boiler drains shall be sent directly to atmospheric flash tank and finally these drains will be routed to condenser.No separate drain collection tank or pumps are envisaged for SCAPH drains.


2 III-MECHANICAL Ch 1: SG & AuxiliariesSection 1 : Scope 1.1.6.1(iv) SHEET 3of 47 2x50% pumps to transfer

condensate from the receiving vessel to the main condenser shall also be provided.

3 III-MECHANICAL

Ch 1: SG & AuxiliariesSection 2 : Design Basis ofSG & Auxiliaries and SCR

2.19(I&iv) ;SHEET 81 of 120 The blow down system shall…...3x50% condensate transfer pumps located inSteam Generator area……

4VII-TENDER DRAWINGS MECHANICAL

FLOW DIAGRAM OF STEAM AND FEDD WATER SYSTEM

DWG NO:111-11-1100 2X50% CONDENSATE TRANSFER PUMPS ARE INDICATED IN THE DRAWING

5 III-MECHANICAL

Ch 26 : Power Cycle Piping, Valves,Fittings & Thermal Insulation

26.6(B-Fittings )(e) SHEET 6 OF 26SPECIFICATION FOR PIPE FITTINGS :

Construction of Alloy steel fittings :Seamless

Y-Pieces will be of spherical construction (seamless forgings welded) instead of cylindrical seamless type as they are not recommended in high temperature steam service due to very high wall thickness which adversely af-fect the start up cycle of boiler-turbine.


6 III-MECHANICAL


26.9.1(II) SHEET 13 OF 26 Each rod of a double rod hanger support shall be designed for the fullhydro test load coming on the double rod hanger assembly.

Each rod of a double rod hanger support shall be designed for operating load coming on the double rod hanger assembly.


7 III-MECHANICAL


26.9.3(II) SHEET 14 OF 26 Snubbers shall be designed to withstand twice the rated load Selected snubbers shall be capable to withstand the design load .The provision as per bidding specification shall prevail.

8 III-MECHANICAL


26.9.3(IV) SHEET 14 OF 26 Construction of snubbers shall be of stainless steel. Construction of only the internal parts of snubbers which comes in contact with the fluid shall be of stainless steel.


9 III-MECHANICALCh 27 : Low Pressure Piping,Valves & Specialities

27.1.13 SHEET 4 OF 35 In water service, valves above 300 NB size shall be butterfly valves

Gate Valves are provided for all low pressure water systems for sizes below Nb 400. Only for sizes above Nb 400 Butterfly valves are envisaged. These are adequate for service and are operational without any problems in several projects. Please confirm.


10Volume IIGeneral & Schedules

Ch 5 : Gen-eral Tech-nicalRequirement 22.18 SHEET 106 of 1318

The Bidder shall list out all major items/ equipment/ com-ponents to be manufactured in house as well as procured from subcontractors bought out items (BOI). All the sub-Bidder proposed by the Bidder for procurement of major bought out items including castings, forging, semi-finished and finished components/ equipment etc., list of which shall be drawn up by the Bidder and finalised with the Owner, shall be subject to Owner's approval.

BHEL has a very well-established system of assessment, approval and enlistment of vendors in the Company's directory.

Inducted vendors are capable of delivering various types of material specifications like Alloy Steels including P92&P91, Carbon Steels, SS and Duplex SS meeting the International/National standards and codes.

And also BHEL’s product directory vendors have been supplied all types of material specifications to all thermal boilers including super critical upto 800MW rating. Hence, approval by the Employer is not envisaged for BHEL’s directory vendors.

In-addition to the vendor list indicated in the specification, BHEL will follow their product directory vendors for the products specified.


For point no 2,3& 4 Bidder proposes 2X50% condensate transfer pumps.

Refer clause 2.19(I&iv) ;SHEET 81 of 120 of

Volume III

I. PIPING

PAGE 56 OF 75





Ch 7 : Paint-ing Sheet 10 of 16

INSPECTION: The following coating inspection & test shall be carried out:1. Ambient and steel temperature, relative humidity and dew point min twice in a shift.2. Surface finish & profile check each component or once per 10 m2 after surface preparation.3. Salt contamination test - Free from salt contamination.4. Dry Film Thickness as per ISO 2808 No.6.5. Holiday Test as per ASTM D 5162/ NACE RP 0188.6. Adhesion Test as per ISO 2409 for cross-cut test, or a pull-off test as per ISO 4624/ ASTM D 4541.

Holiday detection test and Adhesion test will be done on-ly for special coatings like PU, Glass flake etc.



Ch 8 : Paint-ing Sheet 13 of 16PAINTING SCHEME FOR C2 AMD C3 ENVIRONMENT11. Buried piping (Internal) Sa 2 ½ Solid rigid poly ure-thane 500 μ Total DFT = 500μ


Ch 27 : Low Pressure Pip-ing, Valves & Specialities

27.10.00 Sheet 14 of 35

Specific technical requirement of laying buried pipe with anti-corrosive treatment27.10.2 Preparation and cleaning of pipingc)On the internal surface for pipes 1000 NB and above, a coat of primer followed by a hot coal-tar enamel or coal tar epoxy painting (cold) shall be applied.

14Volume IIGeneral & Schedule Ch 8 : Paint-ing 13

Sheet 13 of 16

Storage tanks (internal) Sa 2 ½ ; Primer : 3 coats of amine adducts Total DFT =400μ As the storage water tank handles only non-saline water, internal coating is

generally not envisaged. Same is be-ing followed for all projects.


15Volume IIGeneral & Schedule Ch 8 : Paint-ing 18

Sheet 13 of 16

For insulted piping <125 deg C Sa 2 ½Primer : Polyamide cured epoxy coasting 2coatsTotal DFT = 250 μ

Primer : 1 x 20 μ of Heat Resistant Aluminium paint to IS13183 Gr I Finish : 1 x 20 μ of Heat Resistant Aluminium paint to IS13183 Gr I

Total DFT = 40 μ



Ch11 : QAP(Mechanical)

SECTION M1 : STEAM GENERATOR & AUXILIRIES 2.0. Pressure parts

Sheet 2 of 94

The material which can be identified against mill sheet or manufacturer test certificate only shall be used in the manufacture of pressure parts. Material shall meet all the mandatory requirements (and supplementary checks if asked for) of specified specification.




5.1 H.P.PIPING FOR STEAM GENERATOR AND AUX.I. Piping:

Sheet 16 of 94

a) All raw materials used shall have co-related mill test cer-tificate meeting material specification. All test, as given in respective material code (other than supplementary re-quirements), shall be carried out as minimum.



Ch11 : QAP(Mechanical) E)

Sheet 16 of 94e) Non-destructive examination of welds shall be carried out after post weld heat treatment, if any.

NDE of welds will be done before PWHT for all material specification except P91, P92 grades. Only for Gr 91 and 92, NDE will be done after PWHT.



Ch11 : QAP(Mechanical) 5.1 h)

Sheet 16-17 of 94

Non-destructive examination of welds 1. Temperature > 400 Deg, C and/Or pressure exceeding 71 bar.i. 100% RT/UT on butt welds and full penetration branch welds.ii. 100% MPE.2. Temperature > 175 Deg, C upto 400 Deg. C and/or pressure exceeding 17 bar and upto 71 bar.i. 100% RT/UT on butt welds and full penetration branch welds for pipe dia more than 100 NB.ii. 10% RT/UT on butt welds and full penetration branch for pipe dia upto 100NB.iii. 100% MPE.

Inline with IBR and other International standards, the BHEL practice of NDE for piping before PWHT is as fol-lows:1.Buttwelds- a) Boiler piping - ID ≤ 178 mm - 10 % RT ; ID > 178 mm - 100 % RTb) External Piping. For IBR Class I piping : ID ≤ 102 mm : 10 % RT ID > 102 mm : 100% RTFor IBR Class II piping: 10 % RT for all diameter.

2. 100% MT/PT carried out for fillet welds of critical sys-tem and 10% MT/PT carried for non-critical system




5.0 POWER CYCLE PIPING5.1 i)Sheet 16-17 of 94

i) Wherever SR/PWHT is envisaged for alloy steel, above NDTs shall be after SR/PWHT. Only for P91/P92 grades, NDE will be done after PWHT and for all other specification, NDE will be done before PWHT



Ch 27 : Low Pressure Pip-ing, Valves & Specialities

27.13.9 Sheet 16 of 35

CLH & VLH will be primed with Epoxy Zinc rich primer of 50 micron followed by finish painting of Aliphatic Acrylic Polyurethane or equivalent of DFT 65 microns.

Epoxy Zinc rich primer of 40 microns followed by finish painting of Aliphatic Acrylic Polyurethane of DFT 30 mi-crons. Total DFT = 70 microns


Internal surfaces of buried piping will be given the following painting specification as envisaged in Clause 27.10.2 Volume III : Mechanical Works Ch

27 : Low Pressure Pip-ing, Valves & Specialities Sheet 14 of 35

The provision as per bidding specification

shall prevail.

All materials will be supplied complying to the mandatory test requirements of respective ASME/ ASTM specifica-tion.

J. FPS

PAGE 57 OF 75




1 Vol-III 24 - Fire Detection, Alarm and Protection system

24.4.2 –A) xi) Velocity limit is 3 m/s As per TAC the maximum allowable velocity is 5m/s. Customer is requested to accept the same to avoid the the oversizing of the piping network.



24.4.2 –A) Note 1 and 2 1. All isolation valve in Hydrant system shall be non rising spindle typeGate vale only (For Under Ground Pipelines) and OS&Y type (for Aboveground headers)2. Each isolating valve shall be provided with limit switch.

1. Rising spindle (OS&Y) can be offered for underground piping also for ease of accessibility.2. All isolating gate valve will be locked open. Hence Limit switch is not required for the same.

Everything is required. The provision as per bidding specification shall prevail without any deviation


24.4.2 –B) All instrument root valves shall be stainless steel Gr. 316 globe type. Carbon steel isolation valve is suitable for instrument root valve. Customer is requested to accept the same.



24.4.6 –i) Three (5) nos. of horizontal centrifugal type fire water pumps (3Nos for Hydrant+ 2 Nos for Spray System)with drive electrical Motors…..

Customer is requested to confirm the no. of Fire Water Pumps. Pumping capacity mentioned is tentative. Bidder to estimate the exact quantity.

1 III Sec 2/ Ch 1 2.12.3 Sl No. 7 ID Fans : Fan casing material thickness : Abrasion and wear resistant, high BHN steel having minimum 8mm thickness or 12mm mild steel with liner of thickness 10mm (min.

Fan casing will be of mild steel material as per design standard and casing liner is not applicable for this type of ID Fans of Axial reaction type. The offered ID Fans are of similar design to that of already contracted, supplied and installed ID Fans by bidder for various 660 MW ,700 MW & 800 MW Boilers. ID Fan casing for these Fans are of mild steel only and without any liners.


2

Volume III Ch 1: SG & Auxiliaries, Section 2: Design Basis of SG & Auxiliaries and SCR (Sheet 96 of 120)

12) Dampers and Gates --> ii) ii) The motor operated gates shall be guillotine gate type and shall be provided with 2x100% pressurization fans to achieve 100 % sealing efficiency. Leak tightness efficiency of gate on flow shall be 99.95 %.

a) At economizer bypass duct, the temperature is in the range of 450 to 500 deg.C. and pressure is about -100 mmWC. The leak tightness efficiency without seal air for Economizer bypass guillotine gate achievable is only 99.80 %. However, with seal air blowers, sealing efficiency will be 100 %. For SCR Inlet, SCR Outlet & SCR Bypass Gates, 99.95 % leak tightness efficiency without seal air and 100 % with seal air will be complied. b) For SCR Outlet Gates, since the pressure inside the duct is negative, atmospheric seal air (seal air suction from atmosphere) is considered to achieve 100 % sealing efficiency (instead of pressurization fans). Pressurization fans, if provided in the seal air line, will be subject to high speed rotation since atmospheric air is sucked from outside to inside the duct due to negative pressure inside the duct at this location. This will ultimately damage the pressurization fan (seal air blower). Therfore, atmospheric seal air is considered

Leak tightness efficiency of gate on flow shall be 99.95% or more.

3

Volume III Ch 6: FGD System(Sheet 5 of 54)

6.1.4) Absorber System --> a) ii) & b) i)

a) Motor operated gas tight guillotine type isolation dampers shall be provided at the following locations for each unit: . . . ii) Clean gas duct at outlet of each absorber

b) Multi louver damper quick opening pneumatic/motor operated ahll be provided at following locations for each unit.i) Clean gas duct at outlet of each absorber.

In the Clean gas duct at outlet of each abosrber, as per clause no: 6.1.4) ---> a) ii), Guillotine Gate is mentioned, whereas, as per clause no: 6.1.4) ---> b) i), Multi louver damper is mentioned. Please inform whether to consider Guillotine Gate (or) Multi louver Damper in the Clean gas duct at outlet of each aborber.

Guillotine damper (gate).

4 Volume III Ch 6: FGD System(Sheet 20 of 54)

6.4.2.3) Damper Gas Tightness - . . . Multi louver gate type dampers mentioned in the tender specification . .. . There is no term like Multi louver gate type damper. Bidder understands that the requirement is Guillotine type damper (gate). Please confirm.

Guillotine damper (gate).

5

Volume VI- Tender Drawings

Flow Diagram Air and Flue Gas

DWG. No. 111-11-1200 Rev.0 In the flow diagram for air & flue gas, Guillotine Gates are shown at SCR Outlet & SCR Bypass locations. In addition to the above Gates, one Biplane Damper and one more Guillotine Gate is shown at Flue Gas APH Inlet in the flow diagram.

As per the power plant layout, please note that SCR Outlet duct & Flue Gas APH Inlet Duct are one and the same. Therefore, in the flue gas duct between SCR & APH, bidder is considering Guillotine Gates at SCR Outlet duct (which is the same as flue gas APH Inlet) and also at the SCR Bypass duct. Please confirm our understanding.

Bidder Understadning is correct.

K. SG AUXILIARIES

PAGE 58 OF 75




6

Volume VI- Tender Drawings

Flow Diagram Air and Flue Gas

DWG. No. 111-11-1200 Rev.0 In the FGD Bypass duct, both Biplane Damper and Guillotine Gate are shown in the drawing.

When the FGD is in operation, the FGD Bypass Biplane Damper will be closed (ensuring 100 % sealing efficiency with seal air fans). However, the FGD Bypass Guillotine Gate cannot be kept closed as emergency situation may arise suddenly. (The Gate will take not less than 5 minutes considering the Height of the Gate Blade to slide open). In case the FGD Bypass Gate is also kept closed and emergency situation arises, the purpose of providing the Quick Operating Biplane Damper in Bypass duct is lost and serves no purpose. So, this Gate will be open all the time – whether FGD is in service or FGD not operating. Hence, only Quick-acting Biplane Damper is required and Guillotine Gate is not required in the FGD bypass duct. Globally, only Damper is being supplied in the FGD Bypass Duct and Guillotine Gate is not required in the FGD Bypass duct.Kindly confirm.


7

III

Ch.9

2.10 13), 14) &15) 13)Spares for cleaning device14) Bushings for worm gear reducer.

15) Actuators

Spares for Retract type & Multimedia soot blower shall be offered as given below instead of Swiveling arm type cleaning device spares indicated in Cl.2.10 13) & 14) 1) Spares for Retract type Soot blower: a) Chain – 1 Set b) Glands – 1 Set c) Oil seals & Gaskets – 1 Set d) Bearings – 2 Sets 2) Spares for Multimedia soot blower: a) Valve stem packing - 2 Nos b) Companion flange gasket – 1 No c) Flexible valve seat -1 No d) Lance tube gasket – 1 No e) Feed tube gasket – 1 No f) Feed tube packing – 4 Nos Actuators are not applicable.


8III Ch.1,

Sec-22.9.1 V) 1. Two tiers of heating elements shall be provided. Number of tiers depends upon the total depth required for the performance.

Two tiers will be provided if the total depth is less than or equal to 2000 mm else three tier will be provided.


9

III

Ch.1,Sec-2

2.9.1 V) 2a). Heating elements - Cold end:A cold end tier of elements shall be designed deep enough to encapsulate any Ammonium Bisulphate (ABS) and acid condensation fouling within the cold end tier.Made of vitreous enameled steel with minimum 1.0mm thick base and additional 0.15 mm enamel thickness on each side.

For enameling the thickness of sheet used shall be 0.8 mm instead of 1.0mm in line with International practice.For high ash Indian coal with ammonia slip restricted to less than 2.0%, ABS potential is less. Hence BHEL suggests corten steel elements instead of enameled elements. This is in line with all our contracts with SCR.


10 IIICh.1,Sec-2

2.9.1 V) 4ii). The maximum air-in leakage to flue gas after 3000 hours of continuous operation of the boiler with coal shall be guaranteed and demonstrated. The Bidder shall also demonstrate that the drift in air heater leakage does not exceed 1%, one year after the demonstration of above guaranteed air-in-leakge. Within this period of operation till all air heater demonstration are completed only external adjustments fo seals without needing any shut down for replacements or internal adjustments shall be allowed. …

Leakage test will be done along with boiler PG test within or just after completion of 3000 hours as boiler tuning is mandatory for conducting APH leakage test.The drift in leakage after 1-year operation will be 1 to 2%. Prior to boiler PG test, internal inspection / adjustment of Air Preheater Seals & Sealing surfaces is required as per Air preheater test code ASME PTC 4.3.


11 IIICh.1,Sec-2

2.9.1 V) 5).

i)1 No. peripheral / centrally mounted AC drive, with gear box and automatic clutching/declutching facility. Alternatively, centrally mounted APH AC Drive system having sufficient space for mounting emergency drive and having handling facility with proven experience may also be acceptable.

(ii) 1 No. independent air motor drive, with its gear box and automatic clutching, declutching facility for rotation during non-availability of A.C. drive system.

BHEL standard Air preheater drive shall consist of one AC Motor (main drive) + one air motor (auxiliary drive) + space for emergency AC drive coupled to a common three input gear reducer having over-running clutches will be provided, in line with the other boilers operating trouble freely in India.Hence the word “independent” in Clause (ii) may be removed.

Agreed.

12 IIICh.1,Sec-2

2.9.1 V) xi) a).

Sufficient space provision for future installation of minimum additional 15% of APH heating surface area shall be made in the design so that, the same can be installed, if required. The …..

15% of APH heating surface or 300mm whichever is less is sufficient for future provision. This is in line with our standard practice for all our contracts.


PAGE 59 OF 75




13 III Ch.1,Sec-2

2.9.1 V) xi) c).

On-Load High pressure water washing system (From cold end only):One semi retractable device per APH either stand alone or ….. This system shall use needle jets of high pressure water at 200-300 bar(g) provided…

will lead to APH plugging. Hence offload high pressure washing is recommended. Water pressure of 100-150 bar(g) is sufficient to clean the cold end element depth. Very high pressure water may damage the elements.

Agreed.

14 III Chapter 1, Section 3 Clause no 8.2 Page no 13 of 15 and 15 of 15

Spacing between the collecting electrode (c/l to c/l) transverse to gas flow*.... 300mm...

* A spacing of 400mm for the last two series fields is also acceptable. (corresponding to 400mm, SCA shall be 195m2/m3/s)

BHEL offers 400mm spacing design for all the fields. This is in line with ESP supplied for recent 500/600/660/800MW projects.It is contemporary design and will have following advantages over 300mm spacing or combination of 300 & 400 mm spacing design:• Better and Stable Electrical conditions.• Better alignment tolerance for internals.• More space & easy maintenance for internals.Purchaser/consultant may please confirm for 400 mm spacing for all fields.


15 IIIClause no 8.2 Page no 13 of 15 and 15 of 15

Chapter 1, Section 3

Spacing between the collecting electrode (c/l to c/l) transverse to gas flow*.... 300mm...

* A spacing of 400mm for the last two series fields is also acceptable. (corresponding to 400mm, SCA shall be 195m2/m3/s)

8.2 Minimum specific collection area- Guarantee Point- 260m2/m3/s, for guarantee and design point

The minimum specific collecting area mentioned in the tender is 260m2/m3/sec @ Guarantee point and Design point conditions corresponding to the electrode spacing of 300 mm. BHEL offers all fields with 400mm for all the fields and accordingly, the minimum Specific Collecting Area (SCA) corresponding to the electrode spacing of 400 mm worked out as 195 m2/m3/sec (260 * 300/400) = 195 m2/m3/sec.Hence BHEL offers ESP with SCA of 195 m2/m3/sec corresponding to an electrode spacing of 400 mm.


16 III Chapter 1, Section 2 Clause no 2.21.23 c) Page no 117 of 120 Design basis for Cyclone separator is furnished

In case of SCR requirement, Purchasers/owners are not considering Cyclone separator system in any of the 660/800 MW projects. Hence the purchaser/consultant may please review and confirm the applicability of cyclone separator in the scope of supply.

Agreed.

17Vol.II

Vol.III

Ch.2, Pg.34/1318

Ch.5 Pg.301/1106

Appendix -I

Annexure-I

Raw water analysis

Raw water analysis

Raw water analysis is provided in 2 places in tender document. Kindly confirm which is to be considered for Water treatment plant design. Refer Amendment.- 04

18 Vol.III Ch.5 Pg.301/1106 Annexure-I TDS: 175ppm. The sum of cations and anions totals to 208ppm. Kindly recheck and confirm the TDS & individual ions values. Refer Amendment - 04

19 Vol.III

Ch.5 Pg.301/1106

Ch.8 Pg.376/1106

Annexure-I

Annexure-I

Raw water analysis TDS: 175ppm. DM plant shall be designed considering chemical dosing rates: Non ferric alum:50ppm, Lime:25ppm, poly.1ppm, chlorine:5ppm

Clarified water analysis TDS: 318ppm

In Ch.5, it is stated to design DM plant with raw water analysis considering chemical dosage rates whereas in Ch.8, Clarified water analysis itself is provided. Also, there is an increase of 143ppm in TDS in Clarified water analysis compared to raw water analysis. Kindly confirm water analysis to be considered for DM plant and the TDS to be considered.

Refer Amendment - 04

20 Vol.III Ch.8 Pg.376/1106 Annexure-I Clarified water analysis TDS:318ppm The sum of cations and anions totals to 252ppm. Kindly recheck and confirm the TDS & individual ions values. Refer Amendment - 04

21 Vol.III Ch.5 Pg.302/1106 Datasheet- Water treatment plant

2.0 Cascade aerator: 3674cu.m/hr3.0 Stilling chamber: 3800 cu.m/hr4.0 Parshall flumes: 2200cu.m/hr5.0 Flash mixer: 2200cu.m/hr6.0 Clariflocculator: 2200cu.m/hr

The Capacities of Cascade aerator, stilling chamber, parshall flumes, flash mixer and clariflocculator are not inline. Kindly confirm the capacities of each of the systems. Also, please confirm whether the clarifiers are both working or (1Working & 1standby)


22 Vol.III Ch.6 Pg.362/1106 FGD Waste water treatment

Physico- chemical treatment is to be provided in order to reduce totalsuspended solids, adjust the pH, and reduce the heavy metals. Thetreated waste water shall be pumped to ash slurry sump as well as to theash pond through two (2) (1w+1s) Treated FGD waste water pumps Thesolid sludge shall be disposed of suitably.

Since the treated water from FGD is dumped in Ash pond, there is no need for reduction in TSS etc and no treatment is required. TSS in ash pond itself will be very high. Hence we recommend neutralization of FGD waste water and disposal to Ash pond. This is also followed by NTPC in all their FGD projects. Kindly accept.


23Vol.III

Vol.II

Ch.8 Pg.377/1106

Ch.8 Pg.274/1318

DM plant

Funct. Guarantee5.29 b)

Pressure Sand filters Guaranteed effluent: Turbidity <1NTU

Turbidity at outlet of each filter systm shall not exceed 2NTU..

The clauses are contradictory. We propose PSF outlet guarantee of Turbidity <2NTU only. Kindly accept.


24

Vo.III

Vol.II

Ch.8 Pg.380/1106

Ch.8 Pg.275/1318

DM plant

5.30 b)

Datasheet of DM plant:Guaranteed effluent quality from DM plant.

Ion exchange units - Guarantee

Guarantee for DM plant is specified in both the places. We have considered guarantee specified in Vol.II Functional Guarantee of the tender document only. Kindly accept.


PAGE 60 OF 75




25 Vo.IIICh.17 Pg.566/1106

Ch.17 Pg.574/1106

17.1.2CW treatment & chlorination

1.1. iii.

Scope of supply: 72 empty chlorine ton containers….

Chlorine container.Number required: 68

The quantity specified in both the clauses are contradictory. We have considered 68nos. Of empty chlorine ton containers. Kindly accept.

72 empty chlorine tanks should be

considered.

26Vol.II

Vol.III

Ch.8 Pg.274/1318

Ch.38 Pg.1095/1106

5.29 d)

19.01.05

Zero discharge ETPRO permeate: Overall recovery >80%

Reverse osmosis system:Recovery rate: 75%

The recovery specified in both the clauses are contradictory. We have considered 75% recovery for ETP RO system. Kindly accept.


27 Vol.III Ch.39 1100/1106 Cl.39.4 Sewage treatment plantClarification system: Settling of digested sludge in the tube settler. We propose Clariflocculator in place of Tube settler. Kindly accept.


28

Volume VInstrumentation & Control Works

Part B/Ch 8: PROCESSCONNECTION AND PIPING

Sheet | 10 of 10373/678

373/ For DM Plant or DM water services, complete erection Hardware material shall be SS316 only.

For Pre treatment plant, DMplant, ETP , STP, CWTP, chlorination plants, complete erection Hardware material shall be SS316 only. Kindly accept.

Bidder understanding is correct.

29


Part B/Ch 14: Control System for BOP/Offsite Packages

Sheet | 9 of 10488/678 All the PLC control system shall be of same make/model/family

We propose to offer DCS based control system ETP, Chlorination , CW treatment plants to have seamless integration and comon control platform for all water treatment packages. Kindly accept.


30


Vol. V: PART ASheet | 43 of 100

Sheet | 9 of 1062/678

5. Triple and Dual analysers shall be provided forDM Plant Controls and chemical/O2 dosingcontrols.

For DM plant, we are offering instruments in line with the tender P&ID and for effective control and monitoring of plant parameters, In view of this , we are considering dual analyzers for pH & Conductivity measurements at MB outlet (DM water). If any other analyzers are specificaly required for dual / triple measurements, pls furnish the same.


31


Part B/Ch 11: ControlValves With Actuators

Sheet | 6 of 911.07.00 CONTROL VALVE ACCESSORY DEVICES458/678

external volume chambers , Separate moisture separator unit for ensuring dryness of air entering I/P as well as the power cylinder is to be supplied with each control valve and control damper.

In DM plant & other offsite water packages , External volume chamber will be provided for control valves of critical application, Kindly accept.

For valves of small size and non critical application , external volume chamber is not required. Kindly confirm.


32


Part B/Ch 2: Field &Measuring Instruments

Instrument Air System152/678

On collection of water in the drains of instrument air lines, mechanical automatic drains and periodically solenoid operated drains (with electronic timer - 15m, 30m, 60m and 2 Hours & Timing adjustable) are to be provided.

Mechanical automatic drain will be provided in instrument lines , kindly accept.The provision as per bidding specification shall prevail.

33


Part B/Ch 2: Field &Measuring InstrumentsSheet | 41 of 63

2.16.05 Electromagnetic Flow-Meter Flange material-SS316

We recommend the following flange MOC For flange size DN 25 to 300 (1 to 12"):Fixed flange – Stainless steel, F316L – Carbon steel, A105 DN 350 to 600 (14 to 24"):Carbon steel, A105/A515 Grade 70

Kindly accept


34 Volume IV :Electrical Works

Ch-18 : LV Power CablesPage 4 of 12

18.03.00 DESIGN CRITERIA

SPECIFIC REQUIREMENTS / CONSTRUCTIONAL REQUIREMENTS

All the cables, other than single core unarmoured cables,shall have distinct extruded PVC inner sheath of black colour as perIS: 5831.

For offsite water treatment packges, cables shall be laid in overhead trays and trenches in MCC room, as there is no burried cables, we recommend to offer unarmored cables in offsite packages, kindly accept.


35 IIChapter-9: Mandatory Spares

2.18 , 12 (a,b,c) Transformer rectifier controller, rapping controller, Communication controller Bidder shall provide Transformer rectifier which also provides rapping control and communication control. Hence mandatory spares separately for rapping and communication controller are not applicable. Customer may confirm the bidder understanding


36 II

Chapter-9: Mandatory Spares

2.18 , 9b(iv) and 13 Gear Motor - 4 NosDrive Motor - 5 No

Gear motors and rapping motors are the same. Hence bidder shall not consider the motors under 2.18 9b(iv). Customer may review and confirm the bidder understanding

Bidder understanding is correct.Consider as per 2.18(13) pumping motor.

37 IVChapter-10 : ESP, Sheet 3 of 6

10.02.01 Each microprocessor based ESP Control System Field shall be suitably interfaced with Plant DCS located in unit control room as indicated in Drg No. 112-01-1106. With this various parameters of the ESP shall be monitored and controlled from unit control room.

The drawing as indicated is not provided as part of the tender document. Customer may review the same and provide the drawing, if applicable/ required.

Bidder to submit the scheme for review/approval during detailed engineering.

PAGE 61 OF 75




38 IV

Chapter-10 : ESP, Sheet 4 of 6

10.02.04 The annunciations shall be suitably made available in the HMI of ESP PLC. Alternatively microprocessor based ESP rectifier cum rapping sequence controllers suitably interfaced as per tender drawing for ESP control system configuration (Drawing no. 112-01-1106) is also acceptable.

Bidder understands that , in case bidder provides a dedicated control system / PLC for ESP , then same has to be suitably interfaced with the plant DCS for monitoring and control. In such case, interfacing of the HVR cum rapping controllers directly with DCS is not required, as per tender. Customer may confirm the bidder understanding

Bidder understanding is correct.

39 V

Part-B, Chapter-2, Field and measuring instruments

2.19.06, 47 of 63 Level, Volume, quantity & Mass of each Fly Ash storage silo/Bunker, each coal bunker and each ESP Hopper (First Field).

The 3D acoustic sensors aren't indicated in the scope of supply. The 3D acoustic level transmitters are yet to be proven for ESP hopper applications. Bidder understands that the 3D acoustic wave level transmitter shall not be applicable for the ESP first field hoppers. Customer may review and confirm the bidder understanding


40VOLUME VII TENDER

DRAWINGS/ ELECTRICAL

1. 112 01–1220 Protection Details2. 112-01-1200 SLC for TG Building3. 112-01-1201 SLD for Emergency System…

Electrical Single Line Diagram for FGD system is not listed / provided. Customer may provide the same.

Bider to submit SLD during detailed engineering.

1 5/ Part A - 2.04.11This shall include all cables, hardware, software and accessories required forconnecting Bidder’s system upto the remote terminals at Headquarters inLucknow.

The Station LAN/ MIS data can be provided through web based facility on VPN.

However, employer shall provide the leased line/ internet connectivity infrastructure. Bidder terminal point shall be the battry limits. Employer may please confirm.

The provision as per bidding specification shall prevail. However, if any specific issue need to be reviewd the same shall be finalised during contract finalisation stage.

2 5/ Part A - 7.05.00

W understand fire survival cables are to be provided for critical systems like Fire alarm/ detection & protection system, Trip Push Buttons, emergency trip system, safe shut down circuitry pertaining to main plant BTG and not for other areas. Employer may please clarify.

The provision as per bidding specification shall prevail. Bidder to confirm compliance to the specification requirements

3 5/ Part A Appendic I to Part A Cl. 2.2/ Annexure I (iv)

Electrical I/Os required as per Energy Distribution Management System (EDMS),Energy Management System (EMS), Station Electrical system and any otherelectrical system shall also be considered/included by bidder in respective packageI/O list.

We understand EDMS refers to Electrical distribution management system used for control of breakers of electrical switchgear system. Electrical controls (EDMS as per specification) shall also be implemented in DCS. Employer may please confirm. Employer may please furnish the technical specification for EDMS.

Employer may please clarify if energy management system is applicable for the package. In case if the same is applicable, employer may please provide the specification.

EDMS is part of Electrical specification. Refer Amendment-4 (Volume-IV, Chapter 36).

4 5 Part B/ Ch 3 3.39.06

In order to discharge the warranty responsibility, the bidder shall include in his proposal lumpsum price for the provisions of a team of servicepersonnel at Site who will be fully qualified to perform the required dutiesthroughout the warranty period of one year. The Bidder shall deploy atleast one engineer, one supervisor and two technicians in the team.

The state of art DCS features provide the flexibility of remote diagnostics and support. Maintenance of dedicated personnel for warranty is not required.

Employer may review the requirement and consider the deletion of the same.


5 5 Part B/ Ch 3 3.47.01 (2) Any other plant area / building where STATION LAN need tobe provided for the purpose of MIS.

Employer may please furnish the list of buildings to be connected with MIS/ Station LAN.

The provision as per bidding specification shall prevail. However, if any specific issue need to be reviewed the same shall be finalised during contract finalisation stage

L. C&I

PAGE 62 OF 75




6 5 Part B/ Ch 3

3.47.14.03

3.47.15.1(ii)

System shall be suitable for simultaneous use by multiple users. Presently,the system supplied shall be used by 20 nos. users and plant simulatorpackage. However, the system shall be expandable in future toaccommodate additional 05 nos. users through additional client workstationsnetwork nodes and user licenses.

50 nos. client workstations (40 Nos. each with WORK STATIONS, 24”LED display unit, keyboard/ mouse and 10 nos. shall be laptops oflatest model.)..10 nos. spare physical nodes for additional users with complete clientworkstations and user licenses.

In view of two different requirements of MIS client stations, employer may please clarify the number of client work stations and MIS licenses to be considered.


7 5 Part B/ Ch 3 3.49.03 (2) 2 Memory 64GB ECC DDR – 3, 800 SDRAM.

The server configuration indicated as per the tender specification is very high not required for DCS server applications.

Bidder shall propose the proven tested server configuration for various DCS server applications.

Employer may please confirm


8 5 Part B/ Ch 3 3.49.03Intelligent UPS (on line) with all accessories and software for remotemonitoring for each workstation/server

Employer may please clarify if dedicated Mini UPS is to be considered separately for servers and workstations.

Since 230V AC Plant UPS is to be provided, the same shall be used for servers/ workstations also.

Employer may please review and clarify.

Bidder understanding is correct. Redundant UPS feeder shall be extended in the Control desk / Computer room as per finalised plant layout. Bidder to confirm.

9 5Part A

Part B/ Ch 3

Table - "Drive I/Os"

Table 3.2

No. of I/Os required for various type of drives shall be as follows

DRIVE CONTROL PHILOSOPHY (Typical)

Employer may please clarify which drive I/O philosophy is to be considered by bidder.

Bidder to follow the quantities as per PART A Drive IO s (as a minimum) without any deviation. Bidder to note that the functionalities of Drive control philosophy shall be considered while finalising the DDCMIS IO s. Howver, if any specific issue is there to discuss , will be finalised during contract finalisation stage

10 5 Part B/ Ch 6 6.19.11 One set of Conference Table and 25 no’s industrial grade executive class Chairs shall be provided in each conference room at CCR Floor in TG building

We understand one conference table shall be provided in CCR floor in TG building. Employer may please clarify.

Main Conference hall requirements shall be as per clause no 6.19.11 .However other conference halls wih minor changes from quantity of chairs may be acceptable , as decided during contract finalisation. Bidder to confirm

M. LT SWITCHGEAR

PAGE 63 OF 75




1 Vol-IV CHAPTER – 11: 415V SWITCHGEARS AND DC BOARDS

11.01.04 Bidder to ensure that at least 10% spare feeders (minimum 1 No.) of each type & rating in each 415V switchgear/MCC..

10% or min 1 no. spare feeders will be as per below:-a. Unidirectional and Bidirectional motor feeder: Spare feeders based on physical size of the module.b. Supply feeders: Based on SFU/MCCB rating. c. No spare breaker (ACB) feeder (OGs) shall be provided except outgoing motor feeder. d.No spare feeders shall be provided for Incomer/Bus coupler (non-ACB) modules



11.06.01 (v) The working height shall be limited within 300mm to 1900 mm We propose The working/oprating height shall be limited within 200mm to 2000 mm.



11.06.16 (i) Each motor feeder of MCC shall be provided with suitably rated 415/110V control transformer, for arranging control supply for the module.

We propose Control supply for the modules will be provided through control supply bus which takes the supply from one no. of adequate rated CST in each bus section. Each motor feeder will not be provided with individual CST because the above arrangement will meet the requirement


3.01.02 2 of 42As per clause no. 3.01.02, 3.01.03 and data sheet of Generator Transformer, itis ONAN/ONAF/OFAF type. However, as per 3.04.09, it is mentioned thatcooling shall be OFAF type. Please clarify & confirm.

3.01.03 11 of 42

3.04.09If cooler is to be used, then only OFAF rating will be applicable.ONAN/ONAF/OFAF rating will be applicable with radiator bank. Please clarifythe requirement.As per clause no. 3.04.04.xi, core earthing has to be done outside the tank withsuitable bushing.As per our established practice, we use common terminal board for earthing ofcore, core-clamp & tank. The same is mounted on tank cover & accessible fortesting.

Customer has asked for Short Circuit test on Generator transformer. Werequest that Customer may please be asked to review their requirement andexclude this test because of following reasons:

I) SC test is a special test and very costly also. Moreover, Transformer will besent for short circuit testing to a laboratory which will require total period of 3 to4 months, therefore total delivery time should be extended by 3 to 4 months forperforming short circuit test.

II) BHEL has excellent record of short circuit testing for various rating of Powertransformers. Recently, 260 MVA, 22/420/Ö3 kV, 1-phase Generatortransformer was successfully short circuit tested at NHPTL, Bina for NTPCTanda project. Our design and facilities has well proven for Short circuit testing.

Moreover, we shall furnish calculation for thermal withstand capability for shortcircuit for transformer during detail engineering.

Technical Parameters (Data Sheet) for Reactor is not there for Reactor, asgiven for Generator Transformer (page no.:- (37-38) of 42, Volume IV & chapter

Please furnish data sheet of the reactor.

Technical Parameters (Data Sheet) for Reactor is not there for Reactor, asgiven for Generator Transformer (page no.:- (37-38) of 42, Volume IV & chapter Please furnish data sheet of the reactor.

5 IV/31 Data Sheet for Reactor Refer Amendment -4

N. TRANSFORMER

O1. ASH HANDLING PLANT - MECHANICAL

O. AHP & CHP

2 IV/3 3.04.04 8 of 42 Core Earthing OEM standard practice is acceptable.

3 IV/3 3.03.04 6 of 42 Short Circuit Withstand TestThe provision as per bidding specification shall prevail.

4 IV/31 Data Sheet for Reactor Refer Amendment -4

1 IV/3 ccv vcGT shall have ONANA/ONAF/OFAF cooling.

PAGE 64 OF 75




1 III Chapter-21, Sheet 2 of 52 21.2.3: Fly Ash removal

Fly ash collected in Air Pre-heater (APH), Duct Hoppers and Electrostatic Precipitator (ESP) hoppers and stack hoppers shall be transported pneumatically under vacuum to buffer Hoppers provided for each unit.

Bidder proposes that the APH and Duct Hopper shall be transported by slurry system to coarse ash tank and pumped to ash slurry sump either by ash slurry pump or jet pump

Confirmed.

2 III Chapter-21, Sheet 3 of 52 21.2.3: Fly Ash removal Combined tower shall be provided for wetting unit, air washer, collector tank, buffer

hopper and ash vessels of each stream. Accordingly six towers shall be provided per unit.

BHEL proposes three Tower per Unit with two wetting unit,two air washer,two collector tank and two buffer hopper etc in each tower.

Please review & confirm


3 III Chapter-21, Sheet 3 of 52

21.2.3 Fly Ash Removal System (Dry) Six opening shall be required for each silo. As per flow diagram of fly ash silo area, two additional emergency outlet has

been shown in each silo. Kindly confirm the actual outlet required in each silo.

6 openings shall be provided.


21.2.3: Bottom Ash and Fly Ash (Slurry ) System

There shall be four (4) slurry pipes running cross country from ash slurry pump discharge to ash disposal area; out of which two (2) will be working and two (2) will be standby for two units.

As per Flow Diagram of Ash Water and Slurry System total 4 (3W+1S) line is there from ASPH to Ash Dyke.Kindly clarify

Four pipe lines - 2 working & 2 standby shall be from ASPH to Ash dyke.

5 III Chapter-21, Sheet 6 of 52 21.2.10: Drain Pumping System Drains from BA hopper area, vacuum pumps area and Bottom ash hopper overflow water

shall be transported to the AHP clarifier.

As per Flow Diagram of Ash Water and Slurry System sump pump from mechanical exhaust area shown in Ash Slurry sump.

Kindly clarify the drain from vacuum pumps area shall be transported to clarifier or Ash slurry sump.

Drains from mechanical exhauster area shall be transported to the AHP Clarifier.


21.3.1 Overall Design Criteria for the System

Evacuation time of Bottom Ash alongwith ECO & SCR ash shall be 2 hours 10 minutes including line purging.

The evacuation time shall be finalised based on actual ash data furnished by boiler manufacturer. Kindly confirm the same.



21.3.1 Overall Design Criteria for the System Evacuation time of Fly ash (ESP & APH Ash) ash shall be 5 hours including line purging. The evacuation time shall be finalised based on actual ash data furnished by

boiler/ESP manufacturer. Kindly confirm the same.



21.3.1 Other Design Consideration (a)

Capacity of each clinker grinder & jet pump shall be suitable for 90 TPH (dry ash basis) and all associated pipelines etc. leading to Common Slurry sump should be suitable for this.

Capacity of each clinker grinder & jet pump shall be based on evacuation time and actual ash data provided by boiler manufacturer. However, jet pump capacity shall be minimum 90 TPH. Kindly confirm the same.

Confirmed.


21.3.1 Other Design Consideration (b)

Fly ash of each unit will be evacuated through a vacuum conveying system of minimum 360 TPH (Dry Ash) Capacity consisting of six (6) parallel streams each of minimum 60 TPH (Dry ash) capacity.

Capacity of each vacuum line shall be decided based on evacuation time, and actual ash data provided by Boiler/ESP manufcaturer. However, the stream capcity shall be minimum 60 TPH. Kindly confirm the same.

Confirmed.


21.3.1 Other Design Consideration ©

From the outlet of each Buffer Hopper, there shall be four (4) pressureconveying streams per boiler with three (3) streams working and the other as standby. Capacity of each stream shall be minimum 120 TPH (dry ash).

Capacity of each pressure line shall be decided based on evacuation time, no of pressure lines and actual ash data provided by Boiler/ESP manufacturer. However, stream capcity shall be minimum 120 TPH. Kindly confirm the same.



21.3.1 Other Design Consideration(d) Angle of repose in the fly ash silo shall be considered as 45 degree. It shall be based on vendor design. Kindly confirm the same.

Angle of repose for Fly ash silo Shall be 18o instead fo 45o.


21.3.1 Other Design Consideration(d)

Free board of 1000 mm shall be maintainedin the silo.

As per clause no-1.4.12,sheet 47 of 52, the free board of silo shall be 700 mm. Kindly confirm the exact free board .

700 mm

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13 III Chapter-21, Sheet 9 of 52 21.3.4 Layout Consideration One adequately size maintenace building Kindly provide the size and location of the building.

Maintenance building stands deleted.


21.8.2.5 Common make-up water & Recovery Water System (F)

Three (3) LP Water Pumps (1W+2S/B) for two (2) units alongwith pipes,valves, fittings, supports, instrumentation, etc.

4(2W+2S) Nos LP Water pump has shown in Flow diagram of Slurry and Water System. Kindly confirm the actual no of LP water pump shall be considered by Bidder.

3 LP Water Pumps - 1 W per unit + 1 standby shall be considered.

15 III Chapter-21, Sheet 30 of 52 21.8.3.1 Instrument Air System

3 x 100% duty Oil free Screw type Instrument Air Compressors-total (1W/unit + 1 S/B) complete with Intercoolers, After Coolers if required inlet air filter cum silencers, and complete with drive motors, pulleys, belts, piping,valves, strainers, fittings, indication and protective instrumentations, panels, instrument pipings, supports, hangers, specialties etc. shall be furnished formain plant area.

Instrument Air Compresor is not shown in the Ash Handling Flow Diagram. Kindly confirm the same.

The provision as per clause 21.8.3.1 mentioned in bidding specification shall prevail.

16 III Chapter-21, Sheet 30 of 52 21.8.3.2 Instrument Air System

2x100% duty Oil free Screw type Instrument Air Compressors-total (1 W + 1S/B) complete with Intercoolers, After Coolers if required inlet air filter cum silencers, and complete with drive motors, pulleys, belts, piping, valves,strainers, fittings, indication and protective instrumentations, panels,instrument pipings, supports, hangers, specialties etc. shall be furnished for FA Silo Area.

3(2W+1S) Nos Instrument Air Compresor is shown in the Silo Area Flow Diagram. Kindly confirm the quantity .

The Provision as per clause 21.8.3.2 mentioned in bidding specification shall prevail.

17 Flow Diagram- Fly Ash Silo Area

3(2W+1S) Nos Water cooled Instrument Air Compresor is shown in the Silo Area Flow Diagram.

BHEL propose the Air cooled Instrument Air Compressor . Kindly Confirm the same.

Water cooled compressors shall be provided.


21.26 FLY ASH INTAKE/MATERIAL HANDLING

VALVEMaterial of construction The MOC of Ash Intake valves shall be propiretary of Ash Handling Vendor.

Kindly confirm the same.



21.27 FLY ASH BRANCH SEGREGATING VALVES Material of construction The MOC of Ash line valves shall be propiretary of Ash Handling Vendor. Kindly

confirm the same.


20 III Chapter-21, Sheet 45 of 52 21.29 FLY ASH FEED VALVES Material of construction The MOC of Ash line valves shall be propiretary of Ash Handling Vendor. Kindly

confirm the same.


1 VII-D Page 52 of 63 Typical conveyor gallery/tunnel cross section

Cable trays as required for laying HT/LT power/control/screen cables shall be considerd in conveyor gallery itself wherever possible. Separate cable trestle rack shall be considered only in places where conveyor gallery is not available.

Request Customer to confirm the same.


2 IV Chapter-1page 23 of 732 1.02.15 cable & cable carrier system Request customer to confirm whether trenches are acceptable for all MCC

buildings- CHP,AHP,LHP GHP


3 IV Chapter-1page 24 of 732 1.02.25 Drives prone to vibration (CHP) shall have power JB for terminating the

power cables

Does this mean for all CHP drives customer needs JB's before terminating cables in MOTOR.

Please clarify.


4 IV Chapter-1page 26 of 732 1.04.02- xii) All above calculations shall be done manually Same shall be done by ETAP. Please confirm.

Confirmed.

O2. ELECTRICAL AND C&I

PAGE 66 OF 75




5 IV Chapter-1page 29 of 732 1.06.07 The nominal voltage of DC system shall be 220V for control, protection,

annunciation and dc drives. Request customer to confirm whether 110V is acceptable?The provision as per bidding specification shall prevail.

6 IV Chapter-1Page 59 of 732 1.38.03 Battery backup time shall be at least one (1) hour Request customer to clarify that DC battery back up for complete illumination to

be considered as one hour?


7 IV Chapter-1Page 63 of 732 1.44.01-Xii) Switchgear room/MCC room and cable vault shall be pressurized above the atmospheric

pressure to prevent ingress of dust.

Request customer to clarify whether in Cable vault pressurized ventilation is required?

Is this applicable for AHP MCC buildings also. Generally ventilation for AHP MCC buildings is through exhaust fans only. Please confirm.

Cable vault pressurized ventilation is required. It is applicable for AHP MCC buildings also by providing supply air fans & gravity louvers on opposite side

8 IV Chapter-1Page 66/732 1.47.08 Rubber mats shall be provided to meet the safety and other statutory

requirements. Please clarify whether to consider only in front of panels?The provision as per bidding specification shall prevail.

9 IV Chapter-9Page 250 of 732 9.01 Service transformers request customer to confirm whether 3*50% transformer configuration is

allowed?


10 IV Chapter-20Page 418 of 732 20.04.03-iv) Cable trenches shall be provided only in Switchgear/MCC rooms Pump houses also may be allowed for cable trenches. Please review & confirm.


11 III

Chapter-19Page 614 of 1106 1.8-3 PLC / Central Control Desk / Mimic etc. Please clarify the scope related to control desk/mimic.


12 III

Chapter-19Page 614 of 1106

1.8-10 De-interlock switches clarifty the scope of de-interlock switches

The provision as per bidding specification shall prevail. It can be decided during engineering finalization

13 III Chapter-19Page 615 of 1106 1.8-17 Comprehensive Annunciation System Details for the requirement to be shared The provision as per

bidding specification

14 III Chapter-19Page 622 of 1106 1.13-20

Average illumination level (as specified in Specification for Electrical Works) shall be achieved during normal operation of the plant with dust-laden atmosphere for one (1) month.

Please give clarity - Normal operation & dust laden atmosphere to be clearly specified.


15 III Chapter-19Page 673 of 1106 M9-1.5 Minimum three years battery back-up shall be provided in local panel to retain

totalizer reading during power failure. Three years battery back up shall be provided subject to availability in market.The provision as per bidding specification shall prevail.

16 III Chapter-19Page 726 of 1106 1.19)m) 3-D stockpile volume/ Qty measurement device shall be provided on the Machine

suitably. Request customer to clarify the type to be considered (Acostic or laser type ) Type - Acostic.

17 III Chapter-19Page 609 of 1106 1.5-i) handing over of CHP package Handling over to be clearly defined. Can single conveyor/one route

commissioned also be handed over to customer.

No. Full package complete in all respects shall be handed over.

18 III Chapter-19Page 628 of 1106 1.15-xxix.

In Building# ER-2, the MCC shall be arranged on the ground floor with suitable partitions etc. O&M office Room together with Central Control Room shall be located at 1st floor of Bldg. # ER-2.

First floor for control room shall be finalized during detailed engg as per requirement & space issues.

Please confirm.

Confirmed.

19 III Chapter-19Page 633 of 1106 1.18- 2,4 Electrical Bldg. # ER- 3 [MCC Room bldg.] -MCC area shall be air conditioned MCC is generally provided with ventialtion only. AC only for control DCS panels.

Please clarify.

MCC rooms shall be provided with pressurised ventilation. AC f t l

PAGE 67 OF 75




20 III Chapter-19 Page 634 of 1106 1.18-6 One operator’s cabin in each location mentioned below

Please let us know what all electrical/C&I equipments are required in this operator cabin?

This is generally not considered in other projects executed by us

No electrical/C&I equipment will be installed. Only operating personnel will use the Operator's cabin.

1 VI CHAPTER 14 & 8 14.17 & 8.2 8.2 J) viii) Walkways of conveyor galleries : 0.5T/sqm 14.17) Walkways(including walkways of conveyor/cable galleries): 0.3T/sqm

Please confirm which imposed load to be followed for walkways of coal/lime/gypsum conveyor and cable galleries.

Provision as per IS : 875 to be followed

2 VI CHAPTER 11 11.13.3Where so required chequered plate platforms shall be provided for maintenance purpose. Please confirm that walkway gratings/ chequered plate platforms need not be

provided throughout the whole length and breadth of Pipe Racks.Bidder to comply with stipulation of technical specification.

3 VI CHAPTER 9 & 14 9.3.2 & 14.18Horizontal deflections : H/1000 for Conveyor trestles Please confirm that H/1000 deflection limit is only applicable in transverse

direction for Lime/Coal/Gypsum Conveyor trestles and not applicable for longitudinal direction.


4 VI CHAPTER 14 & 5 14.3 & 5.1 Piling shall be used for foundation of transfer houses We request you to please allow us to take open foundations for Transfer houses of height below 20m as in case Conveyor trestles, if permitted by soil


5 VI CHAPTER 14 & 6 14.3 & 6.10.00

14.3) Minimum height of 0.9 m above the finished floor level shall be one brick thick wall plastered on both side.6.10.00) Even where metal cladding is specified, for initial 3m height from the ground level, minimum one brick thick masonry wall shall be provided.

Please confirm what will be the height of peripheral brick walls in case of Junction Towers, Crusher houses for Lime, Gypsum and Coal handling systems.


6 VI CHAPTER 14 & 7 6.14.00 & 14.15 Plinth Protection details Please confirm which clause to be followed for considering plinth protection around structures under CHP, AHP, LHP and GHP.

Clause 6.14 has to be followed.

7 VI CHAPTER 2 2.7

Limestone unloading Shed Please provide us with technical specifications and construction details for the mentioned structure under LHP scope.

Shall be provied through amendment as and when available.

8 VI CHAPTER 2 2.7

Gypsum Dumping Shed Please provide us with technical specifications and construction details for the mentioned structure under GHP scope.


9 VI CHAPTER 2 2.7

Transfer Houses for Limestone handling system Please provide us with technical specifications and construction details for the mentioned structure under LHP scope.Can we assume that technical specs mentioned in CHP chapter are applicable for these also? Please confirm.


10 VI CHAPTER 2 2.7Crusher House for Limestone handling system Please provide us with technical specifications and construction details for the

mentioned structure under LHP scope.Can we assume that technical specs mentioned in CHP chapter are applicable for these also? Please confirm.


11 VI CHAPTER 2 2.7

Underground reclaim hopper and underground tunnels Please provide us with technical specifications and construction details for the mentioned structure under LHP scope.Can we assume that technical specs mentioned in CHP chapter are applicable for these? Please confirm.


12 VI CHAPTER 2 2.7

Gypsum and Limestone Conveyor galleries and trestles Please provide us with technical specifications and construction details for the mentioned structure under GHP & LHP scope. Can we assume that technical specs mentioned in CHP chapter are applicable for these? Please confirm.


13 VI CHAPTER 2 2.6Coal Settling ponds and Tube settler Please provide us with technical specifications and construction details for the

mentioned structure under CHP scope.The provison as per bidding specification shall prevail.

14 VI CHAPTER 5 5.12For preliminary geotechnical investigation report refer Annexure-I Please provide us Annexure-I. Refer Addendum - 01.

15 VI CHAPTER 2 2.7FGD system - Tender drawings Please provide us with Flow diagrams of Lime handling system and Gypsum

handling system under FGD Scope.Refer Amendment-04

O3. CIVIL & STRUCTURAL

PAGE 68 OF 75




16 VI CHAPTER 2 2.1Contour Drawings Please provide us with available Contour drawings of site in AUTOCAD Format. Refer Addendum - 01.

17 VI CHAPTER 15 15.3Ash pipe supporting structure Please provide us with available drawings of whole Ash slurry pipe corridor

route from Main plant to Proposed Ash Dyke, also showing envisaged Garlanding. It will help us in assessing the terrain and number of existing bridges/culverts/crossings etc. along the whole route.

Refer revised Plot Plan attached with Amendment-4.

18 VI CHAPTER 15 15.3Ash pipe supporting structure : Ash dyke from plant area to ash dyke will be supported on existing pedestals…………….If required, new pedestals to support ash pipe will also be constructed by the bidder.

Please provide us with available drawings showing Existing pipe pedestals from plant area upto Ash dyke, so that assessment of need of new pedestals can be made for this project.

Since Buxar TPS is a green field site, ash pipe supporting structure from plant area to ash dyke shall be supported on piperack/RCC pedestals as per revised PLOT PLAN

19 VI CHAPTER 15 15.3 Ash pipe supporting structure

1. Please confirm whether any NEW patrol/maintenance road is required along the ash slurry pipe corridor outside plant bounday upto Ash dyke.2. If new road is required, we assume that Type-III roads as per Clause 23.1 will be applicable for this. Please confirm.

Any road outside Plant Boundary is not in bidder's scope.

1 III Ch 19, sh 14 of 154 1.13 Performance Guarantee parameters For Coal handling system

1) In the specification, design capacities are not mentioned for belt conveyors, paddle feeder, vibrating screen feeder, vibrating feeder, ring granulator, stacker cum reclaimer, travelling tripper. Should we consider 10% margin over rated capacities mentioned. Please confirm.

It would be helpful if separate table is provided for rated/designed capacities for all equipment.

2) Accordingly, should we consider stacker cum reclaimer's peak reclaiming capacity as 3630 TPH Please confirm


2 III Ch 19, sh 14 of 154 1.13 Performance Guarantee parameters

For Coal handling system5. Paddle feeder

Guaranteed capacity is mentioned as 1200 TPH min and 1500 TPH max. However capacity of conveyor BC-1C/1D is 3300 TPH. Please clarify how it is possible to achieve conveyor capacity since only two paddle feeders are working over one stream of conveyor.

The provision as per bidding specification shall prevail for minimum & maximum Capacity of Paddle Feeder (Rotary Discharge Machine)

3 III Ch 19, sh 14 of 154 1.13 Performance Guarantee parameters For Coal handling system Rated and design capacities of apron feeder and dribble feeder are not

mentioned. Please furnish the details.

Bidder to confirm that guaranteed capacity as per bidding specification shall be achieved

4 VII MECHANICAL TENDER DRGS CONVEYOR PROFILES Please confirm if bidder has the provision to optimize buidling dimensions during detail engg.


5 III Ch 19, sh 43 of 154 12, 12.1

Type of drive for BC-1A/1BDual drive with snub pulleyOne drive at head end and other onreturn sidefor BC-6A/6BDual drive with snub pulleyBoth drive at return side

Please confirm if single snub drive is acceptable for these conveyors, instead of dual drive.

a) Single Drive with snub pulley for each Conv.# BC-1A & Conv.# BC-1B is acceptable. Motor rpm as per NIT shall be ensured.

b) Single drive on ground level located in Building# ST-2 is acceptable for Conv.# 6 & C # 6

O4. CHP,LHP & GHP - MECHANICAL

PAGE 69 OF 75




6 III Ch 19, sh 43 of 154 12.1 Dual drive for RYBC-1A/1B

Please confirm which of the following should be considereda) 1x100% motor kW at head end and 1x100% motor kW at tail end with only one motor working at a timeb) 1x50% motor kW at head end and 1x50% motor kW at tail end with both motors working

Please follow option (b).

7 III Ch 19, sh 43 of 154 12.2 Motor rpm It is noticed that 750 rpm is mentioned for BC-1A/B, 7A/B, 8A/B and RBC-1A/B. Please confirm if we can go for 1500 rpm.


8 VII MECHANICAL TENDER DRGS FLOW DIAGRAM OF CHP (D-0444-111-13-5100 Rev0)

In the junction towers, we see that height looks to be less to accommodate diverter gates between dischage conveyor floor and receiving conveyor floor. We propose to use 2-way flap gates instead of diverter gates, since purpose can be met with flap gates also. Please confirm.

Divertor gate shall be provided as per bidding specification.

9 VII MECHANICAL TENDER DRGS FLOW DIAGRAM OF CHP (D-0444-111-13-5100 Rev0)

We see that no DG/flap gate is provided at a) BC-2C/2D discharge feed to BC-2A/2B at Crusher houseb) BC-4A/4B discharge feed to BC-5A/5B at JT-8c) RBC-1A/1B discharge feed to BC-7A/7B at JT-10Please confirm that the arrangement is alright.


10 VII MECHANICAL TENDER DRGS FLOW DIAGRAM OF CHP (D-0444-111-13-5100 Rev0) For RBC-1A/1B discharge to future conveyors, our scope shall be limited to chute at discharge end upto RBC-1A/1B floor. Please confirm.

Confirmed.

11 III Ch 19, sh 14 of 154 1.13 Performance Guarantee parameters

Performance Guarantee Requirement- 18. Noise LevelIndividually and collectively Noise level shall not be more than 85 dBA measured at a height of 1.5 m above floor level in elevation and at a distance of 1.00 m horizontally from any equipment in any direction and at any load condition.

Please confirm if this clause in applicable to Crushers?

If applicable, customer is requested to furnish the technical details / specifications of special arrangement (if required) for suppressing noise.


12 III Ch 19, sh 37 of 154 G.i. Seal plate5mm thk. MS (IS: 2062) seal plate shall be provided throughout conveyor gallery for all conveyors which are installed in overhead conveyor gallery.

The thickness mentioned for seal plate is on higher side. We propose to provide 3.15 mm thk. seal plate which is followed in other projects generally, instead of 5mm thk. Please confirm


13 IIICh 38, sh 4 of 19

Ch 38, sh 12 of 19

38.2.7

3.01.01

Coal pile run off pond:Each chamber shall be sized to treat maximum rainfall water run off from thecoal pile. The rain intensity for one (1) hour peak rainfall shall be considered.&Capacity: 500 m3 each compartment

We are not calculating the capacity considering rainfall data. We are considering 500m3 capacity (for each compartment) directly as mentioned in table. Please confirm.

Confirmed.

14 III Ch 19, sh 99 of 154 M-20, 1.1 RCC deck with vibration isolation system RCC deck with vibration isolation system is considered only for ring granulator crushers, but not for other equipment like conveyor drives, etc. Please confirm.

Confirmed.

15 III Ch 19, sh 19 of 154 1.3 Crusher: The rotor speed shall be in the range of 600-750 rpm.RPM can vary from this range and shall be as per the recommendation of equipment manufacturer, without any compromise on technical parameters. Please confirm if this is acceptable.

Confirmed.

16 III Ch 19, sh 122 of 154 Coal sampling system, 1.0 c) The bidder may offer alternative Sampling System, if necessary, provided it ensures equal or higher performance than the system specified.

Can we offer two stage sampling system with primary sampler, belt feeder, crusher, secondary sampler, screw conveyor, rotary sample collector instead of 3 stage sampling system, with entire coal sampling system inside crusher house/JT-10, instead of a separate tower. As confirmed by manufacturer, this is sufficient for our plant coal application.

Kindly confirm.


17 III Ch 19, sh 124 of 154 E.0, 7 CSU Sample crusher construction:Crusher shall be of …. and suitable vibration isolation system.

In 2 stage coal sampling system proposed by us, separate vibration isolation system is not required since crusher capacity is low. Vibrations will be taken care suitably with RCC encasing/ rubber pads.


18 III Ch 19, sh 36 of 154 x) conveyor technological structure Stringer size: ISMC-200 (Minimum); Stringer size of ISMC-150mm is sufficient for this capacity. Kindly confirm if we can consider this size.


19 III Ch 19, Sh 107 of 154 M-23, 1.1 Paddle feeder shall be furnished and erected complete with rails ……. and an onboard dry type dust extraction system

For coal application, we propose machine mounted plain water dust suppression for Paddle feeder as per our previous project experience.

Kindly confirm if this is acceptable.

Please provide Dry type Dust Extraction System as per bidding specification.

PAGE 70 OF 75




20 VII MECHANICAL TENDER DRGS Conveyor profile of BC-1A/B and plot plan

As per conveyor profile of BC-1A/B, we see that track#2 is passing through WTC-1A, track#3 is passing through WTC-1B and track #5 is passsing through track hopper complex & JT-1.

But it is not matching with the overall plot plan. There is an additional track between WTC-1A and WTC-1B in plot plan and hence track numbering system is different here (Track#4 is over WTC-1B and track#6 is over track hopper complex & JT-1).

Kindly correct the plot plan and arrange for revised copy without the additional track between WTC-1A and WTC-1B

Final track track lay out shall be furnished during Detailed engg stage

21 VII MECHANICAL TENDER DRGS Plot plan We see a facility between WTC-1B and JT-1 on track#5 outhaul side. Please clarify what it is and if it is part of bidder's scope.

On Track# 5 outhaul side (WBCR-1B) Weigh Bridge Control Room facility has to be provided by the bidder

22 VII MECHANICAL TENDER DRGS Conveyor profile of BC-1C/D and plot plan

In the conveyor profile, we see that there is no tunnel portion between equipment hatch#1 and JT-1.

But in plot plan, there is some gap between equipment hatch#1 and JT-1.

We are following profile drawing. Please confirm if it is alright.

Confirmed.

Please follow NIT Profile/ Layout of Conv. # BC-1C/ 1D & JT-1/ THC-1 Drg. No. D-0444-111-23-5202. C fi d

23 VII MECHANICAL TENDER DRGS PLOT PLAN

Side mill arrangement is shown for bunkers now. Please confirm if rear mill arrangement is acceptable.

If yes, conveyors TBC-1A, 1B, 2A, 2B and BC-8A/B will not be existing. BC-7A/B will be extending upto end of Unit#2 with one no. travelling tripper on each stream of BC-7A/B. Please confirm if this is acceptable.


24 III Ch 19, Sh 102 of 154 3.22 Type of bearing

For pulleys, we are considering heavy duty antifriction - double row self aligning spherical roller bearings (not split type bearings).

For ring granulators, we are considering heavy duty antifriction normal spherical roller bearings (not split type bearings).

Please confirm if it is alright.


25 III Ch 19, Sh 117 of 154 1.17.g. Stacker cum reclaimer

A maintenance electric hoist (Minimum 5t capacity) for lifting components fromground level shall be provided. The hoist shall have sufficient capacity to lift the heaviest single piece of equipment in the machinery house. All equipment shall be accessible by the hoist. Hoisting speed in fully loaded condition shall not be less than 4 m/min.

It is not possible to provide 5 T electric hoist inside the Electric House cum Machinery Room. Hence we will provide 5 T capacity chain pulley block.

Kindly confirm.

Confirmed.

26 III Ch 19, Sh 83 of 154 2.2 Sump pump Pump Designation No./ location/ qty: Refer flow diagram As per flow diagram, there are 16 sump pumps in total (8W+8S) in CHP region. Please confirm.

Confirmed.

27 VII Plot plan

We see that a facility is shown on the additional track to the left of track#1 beside ER-1A/WTC-1A. Please confirm if the same is loco shed and if it is part of bidder's scope.

If yes, please furnish details/specification like area, height, etc.

These details will be furnished during detailed engineering.

28 VII Layout drgs AutoCAD copy of plot plan may be furnished.Refer Amendment - 04

29 III Ch 19, Sh 18 of 154 1.15. xiiComplete Coal Handling Plant shall bedesigned to operate 24 hour per dayround the clock.

System shall be designed for round the clock operation.

However please furnish working hours of Coal Handling Plant considering worst coal for 100% BMCR

System shall be designed for round the clock operation.

PAGE 71 OF 75




30 III Ch 19, Sh 33 of 154 4.0.A.i Belting shall be Steel Cord type with FR grade cover [as per Conveyor Data Sheet]…..

As per 13.1 data sheet of belt conveyors, belting shall be either N/N or steel cord.

Hence clause may be modified to"Belting shall be Steel Cord or N/N type with FR grade cover [as per Conveyor Data Sheet]….."

Please follow Conv. Data Sheet Clause No. 13.1 of bidding specification only.

31 III Ch 19, Sh 153 of 154 M-38, 1.0 Passenger cum Goods lift (Electric Traction type)

We understand that this is rope & sheave type elevator with motor mounted in the machine room at top of building.

Please confirm if our understanding is correct.

Confirmed.

32 III Ch 6, sh 4 of 54 6.1.3Limestone handling and grinding system:Front end loaders - 2 nosBull dozer - 1 no.

a) We understand these equipment are dedicated for handling limestone only. Please confirm.

B) Specification/parameters like model, capacity, etc. of front end loader and dozer may be furnished for our further working.

33 III Ch 19 Dozer/pay loader/hydra For coal handling application, we understand that supply of dozers or pay loaders or hydras is not in the scope of bidder. Please confirm.

34 VII Plot plan CHP maintenance buildingWe understand that there is no CHP maintenance buidling in the layout/ specification and hence same is not part of bidder's scope. Please confirm if our understanding is correct.

35 VIIFlow diagram of compressed air

system111-14-6100 Rev0 Service air to rest of BOP

Kindly confirm if service air is to be considered for CHP region also. As per our past project experience, service air is not required for CHP related facilities since DS/ DE/ other auxiliary system is already provided.

Confirmed. Service air is not required. However for D.E/D.S/ other auxiliary system Air Compressor is to be provided as per

36 III Ch 19, Sh 33 of 154 4.0.A.i Belting Belting is considered without any rip detection or rip protection system. Please confirm.

Belting is to be provided with rip detection & rip

37 III Ch 19 Plain water fogging nozzles for dust suppression system

Spray nozzles shall be provided instead of plain water fogging type nozzles for dust suppression system for wagon tippler complex, track hopper complex, machine mounted DS for stacker cum reclaimer & paddle feeder.

However for DFDS system, dual fluid air-water fogging nozzle shall be provided

The provision as per bidding specification shall follow.

38 III Ch 19 Plain water dust suppression system for reclaim hopper complex (at ground level)

As per specification, plain water DS system is not envisaged at reclaim hopper complex. Hence same is not considered. Please confirm.

However, it may be noted that DFDS shall be considered at receipt points of conveyor RC-1 from vibro feeders.

Confirmed.

39 III Ch 19, sh 86 of 154 M-16, 1.2.f Oil lubricated rotary screw type compressor (oil content in air less than 5 ppm) along with Oil Separator & air dryer for all dust extraction systems, is also acceptable.

Please confirm if same type of compressor is acceptable for DFDS system and track hopper BOBR wagon opening compressed air system, since there is no specification.

Confirmed.

Only items covered in bidding specification mentioned in cl. No.1 are under the scope of CHP contractor

PAGE 72 OF 75




40 VII MECHANICAL TENDER DRGS PLOT PLAN FGD areaLayout of limestone and gypsum handling is shown but conveyor profiles, storage shed, flow diagram/scheme for LHP and GHP are not available in tender drawings. Kindly furnish the same.

Shall be developed by the bidder.

41 III Ch6, sh 4 of 54 6.1.3 Limestone handling and grinding system:

Broad list of equipment is furnished. But there are some clarifications like for example belt conveyor - lot is mentioned but conveyor capacity is not mentioned, crusher -2 nos. is mentioned but there is no crusher house in the layout, EOT crane - lot is mentioned but type, location & capacity are not given, Dry type DE system - 2 is mentioned but locations are not clear. Also limestone storage capacity or storage shed details are not mentioned. Hence detailed specification for all the LHP/GHP equipment and layout is required for working out proposal. Kindly arrange for the same.

Refer Amendement-04

42 VII MECHANICAL TENDER DRGS PLOT PLAN FGD areaAs distance between JNT-1 and ball mill building is very less, we assume bucket elevator will be required. But same is missing in Vol III, Ch 6, 6.1.3 list of equipment. Please clarify


43 VII MECHANICAL TENDER DRGS PLOT PLAN FGD areaFor unloading limestone from stockpile into conveyors, vibro feeders /apron feeders might be required under reclaim hoppers. But no such equipment is listed in 6.1.3 Chapter 6, Volume III. Please clarify


44 VII MECHANICAL TENDER DRGS PLOT PLAN FGD areaIn point 3, chapter 6, vol III, 2 nos. vacuum belt filters are mentioned. However, in gypsum handling area in plot plan, 4 nos. conveyors are shown which is not possible. Kindly clarify.


45 II Ch 8, Sh 26 of 78 Auxiliary power

Coal handling plant:Total power consumption for all the equipments including auxiliaries withsingle stream operation at its guaranteed flow path capacity except:-

Lighting Hoists Coal sampling unit Sump Pumps Elevators DS, DE, Ventilation, SW System, Potable water system

Please confirm single stream in which flow path among D1, D2, S1, S2, R1, R2 in clause 5.25.3 of Sh 34 of 78 will be considered for aux. power calculation.

Largest path shall be followed as per cl.no.1.15 (xi, xii) Vol.III, Chapter 19 sheet 18 of 154..

PAGE 73 OF 75




46 II Ch 8, Sh 23 of 78 3.10.2 Station auxiliary power consumption

We presume that limestone handling system and gypsum handling system will not be considered for auxiliary power consumption calculation. Please confirm.

If the same has to be considered , request customer to furnish the duty factor for the same along with list of equipments to be considered.

Duty Factor is 1.0

1 Volume - III Electrical Works

Ch 33 : Emergency Diesel Generator Set 33.01.01

three Nos. of adequately rated SKID mounted Diesel Generator Set located in a separate building with all accessories and related equipments including Isolation Panel.

We propose to offer DG Sets with weather proof enclosure suitable for outdoor installation. Panels and battery chargers shall be located inside the enclosure.

The provision as per bidding specification prevail.


Ch 33 : Emergency Diesel Generator Set

33.03.15 Circuit breaker panel (Isolation Panel). We propose to connect the DG Set directly to EMCC through ACB. Hence an isolation panel is not required.

Agreed



33.05.04:Jacket Water Cooling System

The radiator tubes shall be of copper with sufficient heat transfer area. The radiator tubes shall be as per manufacturer's design. The provision as per bidding specification prevail.



33.05.07:Air intake silencer and filter

Air intake silencer and filter Air intake silencers are not required as sufficient openings in the form of louvers are provided on the acoustic enclosure. However air filters shall be offered.



Ch 33 : Emergency Diesel Generator Set 33.05.09:Instruments for Diesel

Engine

Pressure gauges for lube oil, fuel oil system, jacket water. The indicated equipments are not applicable in the offered genset. The provision as per bidding specification prevail.


Ch 33 : Emergency Diesel Generator Set 33.05.09:Instruments for Diesel

Engine

Exhaust gas thermometers shall be installed in two exhaust pipes coming out of rows of cylinder.

The indicated equipments are not applicable in the offered genset. The provision as per bidding specification prevail.



33.05.10:GENERATOR

The limits of temperature rise shall be in accordance with Class B insulation. The alternators are being manufactured with insulation class-H and temperature rise limited to Class-H at an ambient of 40 degree celsius. We shall offer alternator with insulation class - H with temperature rise limited to class-F at an ambient of 50 degree celsius.



Ch 33 : Emergency Diesel Generator Set 33.05.15:Constructional Features

Constructional Features The constructional features shall be as per manufacturer's standards. Agreed.



33.05.18:Sound Proofing System

The sound proofing system shall be designed to achieve a minimum insertion loss of 25dB /maximum sound level at Â½ meter distance for enclosure/acoustically treated room as per State Pollution Control Board norms.

As per latest CPCB norms the acoustic enclosure shall be designed for 25 db insertion loss at a distance of 1 meter from the enclosure. We shall offer the enclosure satisfying the norm.




33.06.01: Type Test

All equipment to be supplied shall be of type tested design. During detail engineering, the contractor shall submit for Owner's approval the reports of all the type tests as listed in this specification and carried out within last ten years from the date of bid opening.However if the contractor is not able to submit report of the type test(s) conducted within last five (5) years from the date of bid opening,

There is a contradiction in the no. of years of type test. Please clarify. Type test should have been carried out within last 5 years from the date of bid opening.

11Volume II General and schedules.

Ch 9 : Mandatory Spares Sheet 80 of 106

15.00.00 sets of carbon brushes for Generator, and self starter motor Carbon brushes are not applicable for the offered generator as the same is brushless. Kindly delete the same or indicate some other spares. We are considering 1 set of self starter motor. Pls confirm.

Agreed.

Volume-VII-TD-Elec-Final - - SLD of 400kV GIS

Q. SWITCHYARD

P. DG SET

i) Pl ki dl id SLD f 400kV GIS i th i t il bl i

PAGE 74 OF 75




VOLUME IV : ELECTRICAL

WORKS29 29.02.02 i) The GIS configuration shall be based on drawings & SLD enclosed.

VOLUME IV : ELECTRICAL

WORKS29 29.04.01 The basic system connection is shown in Drawing No.D-0444-112-26-01: SINGLE LINE

DIAGRAM of 400 kV GIS Substation.

2VOLUME IV : ELECTRICAL

WORKS29 29.02.02 i)

i) 400 kV GIS comprises the following major componentsa) The 400 kV GIS shall have following bays:aa) Generator Transformer bays : 2bb) Line bays : 4cc) Bus Reactor Bay : 1dd) Bus PT Bay : 2b) The 400 kV GIS shall employ bus configuration with one (1)and half (1/2) breaker scheme.

Please confirm :- i) no. of tie bays to be provided in 400kV GIS since 400 kV GIS is with one (1) and half (1/2) breaker scheme.ii) if any spare bay is to be provided - if yes , whether spare bay shall be equipped or un-equipped bay.

3 Volume-VII-TD-Elec-Final - - Single Line Diagram

Dwg. No. - 112-10-0100, Rev-0 - Sheet - 1of 2

i) Subject SLD shows 2 nos. ST-1 & ST-2 Bays in addition to two nos. GT Bays - GT-1 & GT-2 bays , however Vol-IV - Chapter-29 - GIS does not mention any ST bay in 400kV GIS. Please confirm number of bays to be provided in 400kV GIS.ii) In two nos. GT Bays - GT-1 & GT-2 bays , 624kV , 20kAp Surge Arrester is indicated. Please clarify since these bays are connected to 400kV GIS.iii) In two nos. ST Bays - ST-1 & ST-2 bays , 120kV , 10kAp Surge Arrester is

4 - - - THERMAL POWER PROJECT btpp Model (1) Please provide Contour Map with Plot plan of power plant & switchyard super-imposed in the same since it is difficult to co-relate otherwise.


WORKS29 29.01.04 However, it will be at the discretion of the Owner NLC / NUPPL to accept such alternative

proposed design.i) Please clarify "NLC / NUPPL".ii) Please confirm owner of subject project.

NLC/NUPPL shall be read as STPL.


WORKS29 29.02.05 x)

All associated Civil and structural works including 400 kV GIS building, Switchyard Control Room, Lattice Structures, Gantry,Equipment structure / foundations, Switchyard fencing etc

i) Please confirm number of stories to be provided in switchyard control building. The provison as per bidding specification shall prevail.

Refer Amendment -04.

1

i) Please kindly provide SLD of 400kV GIS since the same is not available in technical specifications.ii) Please kindly also provide 400kV GIS Switchyard Layout & Section for kind reference please.

Refer Amendment -04.

PAGE 75 OF 75

S. NO. VOLUME / SECTION

CHAPTER

SHEET NO. CLAUSE NO. / S.NO. SPECIFICATION REQUIREMENT STATEMENT OF QUERIES/ CLARIFICATIONS Owner's Reply

1 Vol-II 9 20 OF 106 3.1 Group A/1 Complete assembly of HPT blades (includes inner blade casing and bladed rotor including all internal in assembled condition and fitted in outer casing along with Breach Nuts (if applicable)

1 No Bidder understands that bidder has to offer 1 no. complete assembly of HP Turbine instead of HPT blades.Customer to confirm.

Only Rotor complete assembly. Confirmed.

2 Vol-II 9 20 OF 106 3.1 Group A/2 Complete assembly of IPT blades (includes inner blade casing and bladed rotor including all internal in assembled condition along with full set of both ends of stationary gland seal segments(Finned)

1 No Bidder understands that bidder has to offer 1 no. complete assembly of IP Turbine without Outer casing instead of IPT blades.Customer to confirm.

Confirmed

3 Vol-II 9 20 OF 106 3.1 Group A/3 LP Turbine bladed rotor assembly 1 No Bidder understands that In case of Twin LPT configuration & both Identical LPT Rotors, bidder has to offer 1 no. LP Turbine bladed rotor assembly.Customer to confirm.

Confirmed

4 Vol-II 9 21 OF 106 3.1 Group A/8 AC jacking oil pump complete assembly for Main Turbine along with complete coupling

1 No Bidder understands that AC JOP with complete coupling is to be offered without motor.Customer to confirm.

Confirmed

5 Vol-II 9 21 OF 106 3.1 Group A/9 DC jacking oil pump assembly for Main Turbine along with complete coupling

1 No Bidder understands that DC JOP with complete coupling is to be offered without motor.Customer to confirm.

Confirmed

6 Vol-II 9 21 OF 106 3.1 Group A/10 EOP for lubricating system for Main Turbine along with complete coupling

1 Set Bidder understands that EOP with complete coupling is to be offered without motor.Customer to confirm.

Confirmed.

7 Vol-II 9 24 OF 106 3.2 Group B/22/ d to k HP By Pass System Bidder understands that these spares are inadvertently classified under HP By pass system as these spares are not part of this system.Customer to confirm.

Confirmed. However bidder to supply these spares.

8 Vol-II 9 25 OF 106 3.2 Group B/22.j Electro hydraulic converter assembly of LPBP. 2 Sets Bidder observes that EHC for LPBP has been specified at so many places as under :3.2 Group-B S.No.21.f (Page 24 of 106) : QTY 1 no,3.2 Group-B. S.No. 22.j (Page 25 of 106) : QTY 2 Nos,III C&I Mandatory Spares / 1.00.19.02/ (x): QTY : 2 Nos.The quantity specified seems to be on higher side as Bidder recommends to keep only 1 Set of Equivalent spares as Mandatory spares.

Similarly 2 No.s position feedback transmitter for LPBP is specified at III C&I Mandatory Spares / 1.00.16 / D.i (Page 96 of 106).Customer is therefore requested to review the Quantity specified for all the above spares to avoid duplicay of spares.

Quantity shall be 2 Nos. Follow specification Clause 1.00.19.02/ (x)

R. TG SPARES

Page 1 of 3


CHAPTER


9 Vol-II 9 100 OF 106 III C&I Mandatory Spares / 1.00.19.02/ (x)

Electro-Hydraulic Converter/Servo unit and position feedback transmitter for LPBP and HPBP

1 Set

10 Vol-II 9 28 OF 106 3.3 Group C/1/z Valve seat for HPSV,HPCV, HPBYPASS VALVE, HPBYPASS SPRAY VALVES

1 No. of each These spares are already specified under 3.2 Group-B / S.No.13 and S.No.17 (Page 23 of 106) as part of Valve internals for HP stop and control valves respectively. To avoid repetition of spares, bidder requests to delete these spares from Mand. spares specification.Customer to confirm.

11 Vol-II 9 28 OF 106 3.3 Group C/1/aa HPSV, IPSV spindle with cone 1 No. of each12 Vol-II 9 28 OF 106 3.3 Group C/2 Governing System Spares ( High pressure

governing system) for Main turbine, LP bypass, HP Bypass

These spares are already specified under 3.2 Group-B / S.No.13, S.No.15, S.No.17, S.No.19, S.No.21/a and S.No.21/c (Page 23 & 24 of 106) as part of Valve internals for HP stop,HP control, IP Stop, IP Control, LP Bypass stop and control valves respectively.To avoid repetition of spares, bidder requests to delete these spares from Mand. spares specification.Customer to confirm.

Spares under clause 3.3 group C/2 is deleted.

13 Vol-II 9 28 OF 106 3.3 Group C/3/a Complete rotating assembly with impeller rotor and coupling

1 No Complete pump is already specified under 3.1 Group-A S.No.14 (Page 21 of 106). To avoid repetition of spares, bidder requests to delete these spares from Mand. spares specification.Customer to confirm.


14 Vol-II 9 70 OF 106 II - ELECTRICAL PACKAGES / 1.02.00/

h to j

Gas System:Bearings & seals for fan and gas drierThermostat for gas drierDessicant for gas drier

---- These parts are not applicable for Refrigeration type Gas Drier and 1 no. Refrigeration type gas drier has already been covered at 3.1 Group-A S.No.21 (Page 22 of 106).The same is not recommended to be offered again here to avoid duplicacy.Customer to confirm.


15 Vol-II 9 95 OF 106 III C&I Mandatory Spares / 1.00.16

Mandatory Spares for Solenoid Valves, Control valves, Power Cylinder, Control Dampers, Actuators, Flow Elements and Accessories

Bidder understands that spares that are not specified elsewhere in the specification are to be offered here to avoid duplicacy of spares.Customer to confirm.


16 Vol-II 9 99 OF 106 III C&I Mandatory Spares / 1.00.19.02

Other TG Related Sub-Systems Turbine Supervisory System/EHTC/TSC/ATT/ATRS/GSPC/TDBFP etc.

Bidder understands that spares that are not specified elsewhere in the specification are to be offered here to avoid duplicacy of spares.Customer to confirm.


17 Vol-II 9 100 OF 106 III C&I Mandatory Spares / 1.00.19.02/ (ix)

Electro-Hydraulic Converter/Servo unit and position feedback transmitter for main turbine

1 Set 2 sets of Electrohyraulic convertor assembly for Main turbine is already specified under 3.2 Group-B /S.No. 22.i (Page 25 of 106) and 2 No.s position feedback transmitter for main turbine valves is specified at III C&I Mandatory Spares / 1.00.16 / B.f (Page 96 of 106). To avoid repetition of spares, bidder requests to delete these spares from Mand. spares specification.Customer to confirm.

The spares under clause no. 1.00.19.02 (ix) is deleted.

In addition to clause under 3.2 Group B, Bidder shall supply these spares also.

Page 2 of 3


CHAPTER


LV SWITCHGEAR

Aux. Contact set of each type & rating 6 sets

In LV switchgear panel of Oil Purifier, the specified spares are installed in 1 no or 2 nos. Offering large quantity as specified is not recommended by Bidder to be kept as spares. Accordingly, Bidder will offer following quantity of these spares as per bidder recommendation :

1 Set

Limit switches of each type & rating 6 Nos 1 No. of each typeFixed contact set of each type & rating 6 sets 1 set Moving contact set of each type & rating 6 sets 1 set Current transformer 3 No 1 No Power contactor 5No 1 No of each type Thermal Bimetal relays 6 No 1 No of each type

Customer to confirm.

The provision as per bidding specification shall prevail.Vol-II 9 77 OF 106 II - ELECTRICAL PACKAGES / 9.00.00

18

Page 3 of 3

SN Volume No. Section/Chapter No. Page No. Clause no. Description as per tender document Query from BHEL Owner's Reply

1 Volume-III Chapter 2: Steam Turbine & its Auxiliaries/ Section 2: Design Basis/ Page 28 of 70

Page 28 of 70(Page 246 of 1106)

3.1 (viii) Maximum oxygen content of condensate leaving the condenser shall be 0.015 CC per litre over the entire load range.

For supercritical projects, oxygen is dosed in the condensate system to prevent the corrossion of the piping and fittings. Hence, limiting of oxygen content to 0.015cc/l at hotwell outlet is not required. This is in-line-with the practice adopted for other 660/ 800 MW supercritical projects and is an internationally accepted practice.Customer is requested to accept the same and remove this clause.

The Provision as per bidding specification shall previl.

2 Volume-II Chapter 8: Functional Guarantees & Liquidated Damages/ Page 28 of 78

Page 28 of 78(Page 263 of 1318)

5.9 (ii) Oxygen content in condensate at hotwell outlet shall not exceed 0.015 cc/ litre over …

For supercritical projects, oxygen is dosed in the condensate system to prevent the corrossion of the piping and fittings. Hence, limiting of oxygen content to 0.015cc/l at hotwell outlet is not required. This is in-line-with the practice adopted for other 660/ 800 MW supercritical projects and is an internationally accepted practice.Customer is requested to accept the same and remove this clause.


3 Volume-V Part A/ Appendix-V to Part-A, Minimum Requirements for Field Instruments/ Page 94 of 100

Page 94 of 100(Page 113 of 678)

2.00.01 (i)(o) U tube manometer with Hg filled for direct measurement of condenser vacuum shall be provided in the fixed with isolation valve for local indications.

CPCB (Central Pollution Control Board) has recommended to phase-out mercury containing instruments and replace them with safer alternatives. As Mercury is hazardous and highly toxic for human health and environment, the use of mercury has been banned by BHEL. Therefore, mercury filled manometer can not be supplied by BHEL. "Bourdon Tube Type" pressure gauge for direct measurement of condenser vacuum shall be provided. Its sensitivity & accuracy is better and is industry acclaimed.

Bidder clarification Agreed.

4 Volume-II Chapter-11: Quality Assurance Requirements/ Sheet 4 of 14

Sheet 4 of 14 (Page 433 of 1318)

2.5.1 Inspection Plan:QA plans for the components indicated therein are enclosed in Tables 1 to 3 at end of this chapter.

Table 1 to 3 are not found. Please provide the same.


5 Volume-VII Tender Drawings-Mechanical/Flow diagram of MS, CRH & HRH (Drawing No. 111-11-0200)

Page 3 of 63 Refer zone G-6, F-5 & D-4, C-4- DPTs have been indicated across strainers.

Steam Strainers are integral part of HP & IP turbine stop valve and hence separate strainers as well as DPTs as indicated in these zones are not applicable. Agreed

S. TG AREA

Page 1 of 2

SN Volume No. Section/Chapter No. Page No. Clause no. Description as per tender document Query from BHEL Owner's Reply

Ch. 2 Vol-III Section-2 3 of 70 2.2.2.1 (I)

Final feed water temp. for HeatRate guarantee point & EMCRcondition: By Bidder but not lessthan 300 Deg C at terminal point.

We believe that Bidder is free to optimize final feed watertemperature based on thermal cycle optimization, which shouldnot be less than 300 Deg C.

Agreed

Ch. 2 Vol-III. Section-2 25 of 70 2.20.1 (8) Final feed water temp. for optimizedat 100% TMCR: 306 Deg C

Customer to confirm. Bidder to Refer Clause 2.2.2.1(i) page 3 of 70 as per bidding specification.

6

Page 2 of 2

Documents

EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 … · 2018-10-30 · TDBFP - Operating floor and MDBFP - 0.0 M Floor. The provision as per bidding specification shall prevail