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ODISHA POWER GENERATIONCORPORATION LIMITED

BANHARPALI, JHARSUGUDA ODISHA 768234 INDIAIB THERMAL POWER STATION 2 660 MW UNITS 3 & 4

Comments Resolution Sheet: Continued.

Date:10-02-2015

Reference: OPGC/BOP/0841/01-08-2014Subject: Comments on: P&ID for service water distribution system.Comment Resolution Sheet: 1SL. No.OPGCL / DCPL Comments

Date: 22-03-2014BGR Replies / Resolution

Date: 29-04-2014OPGCL / DCPL Response

Date: 21-05-2014BGR Replies / Resolution

Date: 23-07-2014OPGCL / DCPL Response

Date: 25-07-2014BGR Replies / Resolution

Date: 09-02-2015OPGCL / DCPL Response

Date: 16-02-2015

Rev_0Rev_1Rev_2

2.Pipe size calculation to be furnished considering required flow rate and pressure at various consumptive points.These piping systems governed predominately by gravity network, hence no separate calculation envisaged.Flow rate and available pressure to be indicated for all distribution points. The same shall be substantiated by backup calculation [network analysis]Service water overhead tank elevations are indicated in the drawing. Moreover usage of service water is always intermittent. Hence, it is not possible to indicate flow for all consumption points.Please indicate tank filling rate or intermittent demand as considered for pipe sizing for each building. Please note that velocity through gravity pipe line should not exceed 1.0 m/s. It seems that the pipe sizes as considered are in lower side. Please check.Calculation is enclosed.Noted.

7.----The following SW connection shall be taken from service water pump discharge instead of Gravity flow:

a) Hydrogen generation plant

b) Clarified water P/H.

c) Sludge disposal P/H.

d) ETP.

e) DM plant(Existing)Since pump discharge pressure is too high, gravity flow is provided.Since elevation of top of chemical bldg. & DM Plant (existing) is same, it is recommended that tapoff may be taken directly from SW supply header.Drawing is revisedNoted.

New comments:

9.--------Please note that BHEL is updating their P & ID with some minor changes in scheme & TP details. The same will be informed after getting it from BHEL. BGR is requested to resubmit this P&I diagram after incorporation of the TP details based on BHEL revised P&I Diagram.Noted and revised.Minor modification in TP shall be incorporated.

10.--------Please make the this (CW P/H header) pipe size minimum as 40NB, to get a minimum filling rate of 3cum/hr so that at least one 500 lit tank can be filled within 10 min.Pls note that this line is taken form pump discharge pipeline directly and it has three tanks each having capacity of 500 lit. Hence NB 25 mm is adequate.Noted.

11.--------Please make this (Time office / gate complex) pipe size minimum as 40NB, to get a minimum filling rate of 3cum/hr so that at least one 500 lit tank can be filled within 10 min.Drawing is revised based on the calculation.Noted.

12.--------Delete level switches in Service water over head tank and show LT as per latest BHEL P&IDNoted and revised.Noted.

13.--------TP location is being updated by BHEL, revised location along with the scheme will be provided after receiving it from BHELDrawing is updated.Minor modification in TP shall be incorporated.

14.--------HCSD pump house common header size shall be minimum 40NB to keep friction losses within permissible range for a flow of 3cum/hr to fill one tank within 10 minutes.Pls refer the enclosed calculation. Revision is not required.We have noted that the common header size has been increased to 80 NB.

15.--------Please check the line size (From T.G building C row to CHP area pipe line)Drawing is revised.Noted.

Points closed:

5.----The following SW connection may please be provide:

a) Plant air compressor building.

b) Auxiliary boiler island.

c) IDCT electrical building.

d) Gate complex.

e) Time office.

f) Fire station.

g) Foam pump house.a) It is in BTG vendor scope. Pl check the dwg no. PE-DG-391-172-N003,Rev-3.

b) It is in BTG vendor scope. Pl check the dwg no. PE-DG-391-172-N003,Rev-3.

c) Provided.

d) Provided.

e) Provided.

f) Provided.

g) Provided.Noted.--

6.----In some of the areas pipe size indicated in pipe rack section is not matching with P&ID. Please check and correct.Piping layout will be revised based on approved P&IDNoted.--

8.----Service water tapping to CW pump house and CW chlorination building shall be preferably taken from Unit 3&4 instead of Unit 1&2.Incorporated.Noted.--

1.BGR to revise drawing and show distribution sequence as per location of various facilities in plot plan.Noted and revised.Noted.------

3.Revised as per PTP P&ID.Noted and revised.Noted.------

4.Change as At Air washer room roofIncorporated.Noted.------

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