Spec for Electrical Heating System Fuel Oil

H:\71510 ADNOC OIL TERMINAL HAMRIYAH FREE ZONE SHARJAH\71\TENDER PACKAGE FINAL 30.03.08\VOL-3 TECHNICAL SPECIFICATIONS\04 ELECTRICAL\4186001-B.DOC

B 13-02-2008 Client’s Comments Incorporated A 29-01-2008 Revised Paragraphs 1.1 and 1.2 NCA PSM 0 25-12-2007 First Issue PSM RS

rev. date Description/issued for By Ckd. client: ADNOC DISTRIBUTION project: OIL TERMINAL HAMRIYAH FREE ZONE SHARJAH Document no. 732/ELE/SPC/007

title: SPECIFICATION FOR ELECTRICAL HEATING SYSTEM (FUEL OIL)

office: Abu Dhabi project: 71510-20 document: 4186001 rev: B sheet: 1 of: 26

SPECIFICATION FOR ELECTRICAL HEATING SYSTEM

(FUEL OIL)

OIL TERMINAL HAMRIYAH FREE ZONE SHARJAH

H:\71510 ADNOC Oil Terminal Hamriyah Free Zone Sharjah\71\Tender Package Final 30.03.08\VOL-3 Technical Specifications\04 Electrical\4186001-B.Doc

client: ADNOC DISTRIBUTION project: OIL TERMINAL HAMRIYAH FREE ZONE SHARJAH Document no. 732/ELE/SPC/007



Table of Contents page

1. SCOPE ................................................................................................................3 1.1 Introduction..............................................................................................3 1.2 Purpose ...................................................................................................3 1.3 Definitions................................................................................................3

2. CODES & STANDARD.......................................................................................3

3. REFERENCE DOCUMENTS..............................................................................5

4. DOCUMENT PRECEDENCE .............................................................................5

5. SPECIFICATION DEVIATION/CONCESSION CONTROL...............................6

6. QUALITY ASSURANCE AND QUALITY CONTROL .......................................6

7. SUBCONTRACTORS/SUBVENDORS..............................................................7

8. HANDLING..........................................................................................................7 8.1 Packaging and Shipping .........................................................................7 8.2 Preservation and Storage .......................................................................7

9. DOCUMENTATION ............................................................................................8

10. DESIGN............................................................................................................ 10 10.1 General................................................................................................. 10 10.2 Design Pressure................................................................................... 10 10.3 Design Temperature ............................................................................ 10 10.4 Thermal design..................................................................................... 11 10.5 Mechanical Design............................................................................... 11

11. ELECTRICAL REQUIREMENTS .................................................................... 14 11.1 Basis of Design .................................................................................... 14 11.2 Main Electricity Supply ......................................................................... 15 11.3 Safety.................................................................................................... 15 11.4 Service Conditions ............................................................................... 15 11.5 Performance Requirements ................................................................. 16 11.6 Construction Requirements.................................................................. 17

12. INSPECTION & TESTING............................................................................... 23 12.1 Inspection & Testing (Non-Electrcal) ................................................... 23 12.2 Inspection & Testing requirements (Electrical) .................................... 24 12.3 Site Acceptance Test ........................................................................... 25

13. SPARES........................................................................................................... 25

14. VENDOR DATA REQUIREMENTS ................................................................. 26

15. GUARANTEES AND PERFORMANCE.......................................................... 26





1. SCOPE

1.1 Introduction

ADNOC Distribution intends to construct a new oil terminal, be located in Hamriyah Free Zone, Sharjah. The oil terminal will comprise of tanks, pump-house, offices, warehouse, truck loading facilities, truck washing facilities, vehicle workshop building, parking facilities, electrical substation(s), and fire fighting station. The terminal will be connected via pipelines to new marine loading facilities (for product loading and bunkering services) at existing berths.

1.2 Purpose

This Specification defines the minimum requirements for thermal & mechanical design, materials, fabrication, testing, inspection, painting, spares, packing and forwarding of Electrical Heating System for Oil Terminal Hamriyah Free Zone Sharjah Project for ADNOC Distribution.

The purpose of this specification is to ensure consistency in all aspects such as design, material, construction, etc. related to Electric Heaters for the Project.

This specification shall be read in conjunction with specification for fuel oil 180/380 Cst Tanks (732/MEC/SPC/004).

1.3 Definitions

COMPANY ADNOC Distribution

CONSULTANT Tebodin Middle East Ltd

CONTRACTOR The party, which carries out all or part of the engineering, procurement, construction, and commissioning of the Project

PROJECT Oil Terminal Hamriyah Free Zone, Sharjah

SHALL indicates a mandatory requirement

VENDOR/MANUFACTURER the party, which manufactures and/or supplies equipment, technical documents/drawings and services to perform the duties specified by COMPANY/ CONSULTANT/CONTRACTOR.

2. CODES & STANDARD

The following applicable Codes and Standards shall, to the extent specified herein, form a part of this specification. The latest edition of these specifications in force at the time of VENDORS bid proposal submission shall be applicable to the materials supplied under these specifications.





American Society of Mechanical Engineers (ASME):

Section II Boiler and Pressure Vessels Code, Material Specifications

Section V Boiler and Pressure Vessels Code, Non-destructive Examination

Section VIII, Div. 1 Boiler and Pressure Vessels Code, Rules for Construction of Pressure Vessels

Section IX Welding and Brazing Qualifications

B 16.5 Pipe Flanges and Flanged Fittings

B 16.20 Metallic Gaskets for Pipe Flanges – Ring-Joint, Spiral-Wound and Jacketed

American Society for Testing and Materials (ASTM)

A-450 Specification for General Requirements for Carbon, Ferric Alloy, and Austenitic Alloy Steel Tubes

A-578 Standard, Straight-Beam Ultrasonic Examination of Plain and Clad Steel Plates for Special Applications

European Committee for Standardization (EN)

EN 10204 Types of Inspection Documents - Metallic Products

EN 50081-2 Electromagnetic compatibility Generic emission standards

EN 50082-2 Electromagnetic compatibility Generic immunity standards

EN50014 through EN 50020 Electrical apparatus for potentially explosive atmospheres

TEMA Tubular Exchanger Manufacturers Association

NFPA 70 National Fire Protection Association

NEMA National Electrical Manufacturers Association

WRC BULLETIN 107: Local stresses in spherical and cylindrical shells due to external loadings.

WRC BULLETIN 297: Local stresses in spherical and cylindrical shells due to external loadings (Supplement to WRC Bulletin No 107).

International Electrotechnical Codes

IEC 60079 Electrical apparatus for potentially explosive atmospheres





IEC 60269-2 Low-voltage fuses. Part 2: Supplementary requirements for fuses for use by authorized persons (fuses mainly for industrial application)

IEC 60398 General test conditions for industrial electro heating eqpt.

IEC 60445 Identification of apparatus terminals and general rules for a uniform system of terminal marking, using an alpha-Numeric notation.

IEC 60529 Classification of degrees of protection provided by enclosures.

IEC 60947 Low voltage switchgear and control gear

IEC 61000-4 Electromagnetic compatibility (EMC) Part 4: Testing and Measurement techniques.

IEC61000-6-2 Electromagnetic compatibility (EMC) Part 6:Generic Stds.,

Section 2: Immunity for industrial environments

IEC61000-6-4 Electromagnetic compatibility (EMC) Part 6. Generic Standards, Sec. 4: Emission standards for industrial environments.

IEC CISPR11 Limits and methods of measurement of Electromagnetic disturbance characteristics of industrial, scientific and medical radio frequency equipment.

International Organization for Standardization (ISO)

ISO-9001 Quality Management Systems Requirements.

ISO-9004 Quality Management Guidelines for performance improvement system

ISO-9011 Guidelines for quality and/or environmental system auditing.

3. REFERENCE DOCUMENTS

732/ELE/SPC/001 Specification for Transformers

732/ELE/SPC/XXX Heater Data sheet

4. DOCUMENT PRECEDENCE

It shall be the VENDOR’S responsibility to be, or to become, knowledgeable of the requirements of the referenced Codes and Standards.

The VENDOR shall notify the CONTRACTOR of any apparent conflict between this specification, the related data sheets, the Codes and Standards and any other specifications noted herein. Resolution and/or interpretation precedence shall be obtained from the CONTRACTOR in writing before proceeding with the design/manufacture.





In case of conflict, the order of precedence shall be:

• Equipment data sheets

• This Specification

• Industry Codes and Standards

5. SPECIFICATION DEVIATION/CONCESSION CONTROL

Deviations from this specification are only acceptable where the MANUFACTURER has listed in his quotation the requirements he cannot, or does not wish to comply with, and the COMPANY/CONTRACTOR has accepted in writing the deviations before the order is placed.

In the absence of a list of deviations, it will be assumed that the MANUFACTURER complies fully with this specification.

Any technical deviations to the Purchase Order and its attachments including, but not limited to, the Data Sheets and Narrative Specifications shall be sought by the VENDOR only through CONCESSION REQUEST format. CONCESSION REQUESTS require CONTRACTOR’S and COMPANY’S review/approval, prior to the proposed technical changes being implemented. Technical changes implemented prior to COMPANY approval are subject to rejection.

6. QUALITY ASSURANCE AND QUALITY CONTROL

The VENDOR shall have in effect at all times, a QA/QC program, which clearly establishes the authority and responsibility of those responsible for the quality system. Persons performing quality functions shall have sufficient and well defined authority to enforce quality requirements that initiate, identify, recommend and provide solutions to quality problems and verify the effectiveness of the corrective action.

A copy of the VENDOR’S QA/QC program shall be submitted to the CONTRACTOR with its quotation for CONTRACTOR’S review and concurrence prior to award. If VENDOR’S QA/QC program and facility, where the work is to be performed is ISO 9000 certified, then only a copy of the VENDOR’S ISO 9000 certificate is required. In addition, if VENDOR’S facility is ISO certified, CONTRACTOR’S QA audit requirements will be waived in favor of ISO 9000 registrar audits, unless the CONTRACTOR’S trend analysis program indicates areas of concern.

The VENDOR shall identify in purchase documents to its SUBVENDORS all applicable QA/QC requirements imposed by the CONTRACTOR, and shall ensure compliance thereto. On request, VENDOR shall provide objective evidence of its QA/QC surveillance of its SUBVENDOR’S activities.

The VENDOR shall submit certified reports of production tests as soon as the tests are completed satisfactorily.





The COMPANY/CONTRACTOR reserves the right to inspect materials and workmanship at all stages of manufacture and to witness any or all tests. The VENDOR, 30 days after award but prior to the pre-inspection meeting, shall provide the CONTRACTOR with a copy of its Manufacturing and Inspection Plan for review and inclusion of any mandatory COMPANY/CONTRACTOR witness points.

7. SUBCONTRACTORS/SUBVENDORS

The VENDOR shall assume unit responsibility and overall guarantee for the equipment package and associated equipment.

The VENDOR shall transmit all relevant purchase order documents including specifications to his SUBVENDORS and SUBCONTRACTORS.

It is the VENDOR’S responsibility to enforce all Purchase Order and Specification requirements on his SUBVENDORS and SUBCONTRACTORS.

The VENDOR shall submit all relevant SUBVENDOR and SUBCONTRACTOR drawings and engineering data to the CONTRACTOR.

The VENDOR shall obtain and transmit all SUBVENDOR and SUBCONTRACTORS warranties to the CONTRACTOR/COMPANY, in addition to the system warranty.

8. HANDLING

8.1 Packaging and Shipping

Preparation for shipment shall be in accordance with the VENDOR’S standards and as noted herein. VENDOR shall be solely responsible for the adequacy of the preparation for shipment provisions with respect to materials and application, and to provide equipment at the destination in ex-works condition when handled by commercial carriers.

Adequate protection shall be provided to prevent mechanical damage and atmospheric corrosion in transit and at the jobsite.

Preparation for shipment and packing will be subject to inspection and rejection by COMPANY’S/CONTRACTOR’S inspectors. All costs occasioned by such rejection shall be to the account of the VENDOR.

All cable drums shall have their identification reference clearly stenciled on the outside of both flanges.

8.2 Preservation and Storage

Equipment and materials shall be protected to withstand ocean transit and extended period of storage at the job site for a minimum period of 18 months. Equipment shall be protected to safeguard against all adverse environments, such as: humidity, moisture, rain, dust, dirt, sand, mud, salt air, salt spray and seawater.





9. DOCUMENTATION

VENDOR shall submit the types and quantity of drawings and documentation for CONTRACTOR’S authorization or information as listed in the individual Material Requisitions and Purchase Orders.

Mutual agreement on scheduled submittal of drawings and engineering data shall be integral part of any formal Purchase Order.

Comments made by CONTRACTOR on drawing submittal shall not relieve VENDOR or SUBVENDORS of any responsibility in meeting the requirements of the specifications. Such comments shall not be construed as permission to deviate from requirements of the Purchase Order unless specific and mutual agreement is reached and confirmed in writing.

Each drawing shall be provided with a title block in the bottom right-hand corner incorporating the following information:

• Official trade name of the VENDOR.

• VENDOR’S drawing number.

• Drawing title giving the description of contents whereby the drawing can be identified.

• A symbol or letter indicating the latest issue or revision.

• PO number and item tag numbers.

Revisions to drawing shall be identified with symbols adjacent to the alterations, a brief description in tabular form of each revision shall be given, and if applicable, the authority and date of the revision shall be listed. The term “Latest Revision” shall not be used.

As a minimum the following information/data shall be submitted:

A) Certified Dimensional Outline Drawing

Certified Dimensional Outline Drawing shall include:

• Reference to applicable design codes, tag number, and service

• Hydro test pressures

• Materials of construction and corrosion allowances

• Insulation thickness

• Empty, operating and hydro test weights

• Overall dimensions

• Lifting lug, earthing boss and locations





b) Detail Drawings

Detail Drawings shall identify all component parts with cross indexed bills of materials and shall include:

• Applicable Specifications and Codes

• Dimensions

• Wall thicknesses

• Fabrication details

• ID balloons for materials of construction, notes and corrosion allowances

c) Shipping And Handling Data

d) Bill Of Materials

• Bill of materials may be on drawings or separate documents.

• Reference balloons shall be used on drawings to identify materials.

• If on separate documents, a reference table shall be shown on drawings.

Bill of Materials shall include:

• All components' materials of construction and quantity

• Sizes, thicknesses, ID balloons, and reference drawings

• ASME Standard designations

• Manufacturer name, model number, and size of proprietary components

e) Calculations

Calculations shall include:

• Thermal design calculations

h) Testing Procedures

• Nondestructive examination procedures

• Hydro testing procedures

f) Spare Parts Recommendation

g) Manufacturing Data Report





DOCUMENTATION (For Electrical)

The Manufacturer shall provide technical manual(s) and drawings in accordance with the

Purchase order requirements, which shall include at least the following documents:

• Single line diagram of the unit;

• General arrangement drawings;

• Control panel layout, elementary diagram, installation details, cable/conduit entry details, and interconnection diagram.

• Main and control circuit schematic diagrams;

• Equipment lists;

• Recommended spare parts lists;

• Test reports and performance curves, including oscillograms;

• Operating manuals, which incorporate installation, commissioning, operating and maintenance instructions, and faultfinding procedures.

10. DESIGN

10.1 General

Vendor shall strictly comply with the design requirements stipulated in the requisition. Any comment and/or reservations shall be resolved with the Client at the bidding stage. Reservations/deviations not accepted during bidding stage shall not be reopened during the job execution.

10.2 Design Pressure

When design pressure is specified as full vacuum (FV) the same shall be taken as external pressure of 1.04 Kg/cm2 (a).

10.3 Design Temperature

10.3.1 The design temperature shall be as indicated on respective drawings/datasheets. However, as the shell of an electric heater is exposed to radiation from the tube bundle (bundle at extreme hot end being warmer than the process fluid at its exit), the Vendor shall indicate in his offer the resultant temperature of the shell at hot end due to the radiative heat transfer between bundle and the shell and the shell assembly shall be designed based on this temperature and the design temperature indicated on the process data sheet which ever is higher.





10.3.2 The minimum design metal temperature (MDMT) shall be taken as 4oC. Equipment shall comply with all the Codes/specification requirements for MDMT such as impact test, heat treatment, radiography etc.

10.3.3 Vendor shall ensure that the minimum design life of the electric heater is at least 30 years.

10.4 Thermal design

10.4.1 Vendor shall be responsible for proven thermal design meeting the requirements of specification data sheet for process stream. Process inputs for heaters to be as per specification data sheet for process stream.

10.4.2 Vendor shall be responsible for vibration free design of the equipment.

10.4.3 The design and layout of tubes shall be such as to avoid any dead pockets. Segmental cut baffles are undesirable due to the possibility of stagnant flow regions behind baffles and shall not be used. Rod-baffle type construction shall be preferred.

10.4.4 Material of construction specified in the datasheets is minimum acceptable. Vendor shall be responsible for the proper selection of material for the fluid being heated and intended equipment life. Selected material of construction for the heater shell and tube/ elements shall take into consideration the corrosive nature of fluid/process stream (sulphur contents etc.). Materials shall confirm to relevant ASME specifications. Castings shall not be used.

10.4.5 For fouling service (with fouling factor > 0.0003 Hr ºC/Kcal m2 ) where mechanical cleaning of outside surface of tubes is required, the tube pitch for tube layout shall be either square or rotated square.

10.5 Mechanical Design

10.5.1 General

a) During the design of equipment, consideration must be given to the stresses induced at operating, alternate operating and other upset conditions, if any.

b) Vendor shall be responsible for sound mechanical design of the containing vessel/assembly. Mechanical design calculations shall be submitted for review.

c) Up to nominal diameter DN 500 ( 20” ) seamless pipe should be used.

d) Minimum thickness of any pressure containing part shall be 6mm plus corrosion allowance.

e) Minimum thickness of closure plate (Unstayed Flat Heads & Covers) shall be designed as per ASME Sec VIII-Div 1, Cl. UG-34.

f) Minimum shell/dish end thickness and maximum unsupported tube/sheath span shall be as per manufacturer’s standard.





Heater Installation/material.

• All heaters shall be horizontal. Contractor to advice mounting orientation and heater connections.

• All heaters shall be provided with suitable spacers and supports to maintain the elements in proper alignment and from direct contact with the shell wall. The spacing of supports shall not exceed 20 inches (508 mm). Spacer & support material shall be the same as the heating element sheath. No segmental baffles are allowed inside the shell.

• Except where specified, the number, length, and arrangement of heating elements shall be by vendor. All radial process connections to the heater shell shall be the same diameter as the shell. This shall be accomplished by the use of welding tees.

• During the design of equipment, consideration must be given to the stresses induced at operating, alternate operating and other upset conditions, if any.

• Shell to tube sheet joint shall be bolted type for easy dismantling and accessibility of tubes for manual cleaning and for easier replacement of bundle.

10.5.2 Tube to tube sheet joint

Tube to tube sheet joint to be strength welded. Compression fittings to seal heating elements to the tube sheets are not acceptable. Brazed tube-to-tube sheet joint are not acceptable.

Equipment nozzle projection should be suitable for the insulation thickness.

10.5.3 Tubes/Sheath

• Minimum thickness of tubes/sheath shall be as under:

Tube OD Minimum thickness in BWG

(Inches) SS Incoloy/Inconel

5/8 16 18

1/2 18 20

3/8 20 22

• The sheath and all pipes shall be seamless.

10.5.4 Nozzles

• All flanges shall be weld neck type.

• One 2”NB flanged MP connection to be provided on process inlet and outlet nozzles. Flanged nozzles for the applicable pressure rating shall be provided as per process requirements and instrumentation requirements. Nozzle projection from process nozzle surface shall be 200 mm minimum.





Also, 2”NB size connections with blind flange shall be provided at the highest & lowest point respectively.

• Equipment nozzle projection shall be suitable for the insulation thickness.

• Minimum nozzle size to be DN 50mm (2”NB).

Integral reinforced nozzles are required if any of the following conditions is applicable.

• The design pressure exceeds 50 Kg/cm2g.

• The design temperature is <-10oC or > 400oC

• Shell thickness in case of CS exceeds 50mm and in case of stainless steel and alloy steel exceeds 25mm.

10.5.5 Gaskets

As a minimum, gaskets for girth joints (i.e. between girth flange and tube sheet etc.) shall be SS 321 spiral wound with flexible graphite filler and with SS321 centering rings or better depending upon the operating and design conditions.

10.5.6 Girth Flange Joints

• All girth flanges shall be of forged hub type and shall have confined gasket joints.

• All girth flanges shall be designed for full bolt load as per ASME Sec VIII Div.1. In gasket seating conditions bolting area provided shall have minimum 5% design margin over the Code requirements for girth flanges.

• Jackscrews shall be provided on girth flanges.

10.5.7 Bolting and Flange Closures

• All bolting shall conform to ASTM A193 Gr B16 with nuts in accordance with ASTM A-194 Gr 4 when connected to stainless steel flanges.

• Shell to tube sheet joint shall be bolted type for accessibility of tubes for manual cleaning from outside and for easier replacement of bundle.

• Heater flange shall be designed as a tube sheet as per ASME Sec VIII Div.1 Appendix A.

10.5.8 Supports

The heater shall be installed horizontally. Equipment supports shall be designed to withstand a pulling force of not less than 1.5 times the bundle weight, taken at the centre line of the exchanger. Analysis shall be based on L.P Zick's criterion. The electric heaters supports shall also be adequate to ensure structural stability of the electric heaters in basic configuration as required considering all superimposed loads. Detailed calculations shall be submitted to this effect.





10.5.9 Stamping

• The vessel shall be ASME-‘V’ stamped unless otherwise specified on the contract documents.

• Each heater shall be identified by a nameplate.

11. ELECTRICAL REQUIREMENTS

11.1 Basis of Design

The heater control panel and associated heater shall be designed to provide continuous operation at rated output for six years at the process conditions stated in the Requisition, allowing for periodic minor maintenance.

Additionally, the equipment shall be designed to function in continuously operating petrochemical process units, production facilities or utility installations and shall have a design life of at least 30 years.

The design shall ensure minimum mechanical stress and fatigue on the heater elements.

The power of each heater shall be controlled by thyristor fired according to the zero crossover mode, i.e., phase angle control shall not be utilized, with a controlled output power range down to 1% (cycle syncopation).

Burst firing technique should not be utilized for large loads attached to relatively weak supply systems susceptible to electrical disturbances, but rather single cycling is preferred. The load should be configured in either four-wire star or delta, with three-leg control using thyristor pairs adopted for the star configuration and two-leg control for the delta configuration.

Large loads should be split into smaller banks. These banks should be controlled either via a thyristor step controller or by thyristor synchronization depending on the process application. If the former is used, then bank rotation control should be applied to ensure that heater stress is equally shared. However, notwithstanding the above, the manufacturer may recommend other control techniques to the Principal, provided that they meet the requirements of this specification.

The application of parallel thyristors shall be avoided. If parallel operation is necessary, current balancing shall be applied.

Thyristor protection shall include over-current protection by means of ultra rapid fuses and voltage transient suppressers. Where deemed necessary by the manufacturer, di/dt limiting reactors and dv/dt protection networks shall be provided.

The input signal to the control circuit shall be 4 to 20mA DC signal with a linear relationship from 0 to 100% power. The maximum allowable output impedance of this equipment shall be 500. The input signal shall be galvanically separated from the driver unit and its power supply.





The Manufacturer shall provide a system to prevent problems during start-up and when flow rates are low, e.g., on fuel gas heaters with large turn down ratios.

Over-temperature protection with pre-alarm shall be provided and trip signals shall be either connected directly to the control panel main contactor in simple installations or via an instrument interface, as specified in the Requisition.

Over-voltage protection shall be provided to avoid damage to any analogue instruments from faults in the thyristor trigger circuit.

Manual/auto selection for output control shall be provided to allow control of the power output via a potentiometer in the manual position. This potentiometer and associated switch shall be designed to be tamper proof.

The control panel shall be protected against the adverse effects of moisture, salt, fungus and vermin.

All components and materials used shall be of high quality and reliability that satisfy the above criteria.

11.2 Main Electricity Supply

The heater shall be capable of operation within the nominal voltage and frequency as indicated in the Requisition and on the basis of the following:

The input supply variations shall be limited, under steady state conditions, as follows:

Nominal system voltage : plus 5% to minus 5%

Nominal system frequency : plus 2% to minus 2%

The AC power supply to the heater shall be symmetrical and sinusoidal, although the input voltage may be subject to transients comprising short term voltage depressions up to 20% of nominal during motor starting, and to voltage interruptions during system short circuits. Transient high frequency voltages of up to 2 KV may also be superimposed on the input voltage as a consequence of system switching operations.

The neutral of the supply system shall be assumed to be solidly earthed, unless otherwise stated in the Requisition.

11.3 Safety

All component items shall be designed to provide a maximum degree of safety during all operating conditions, inspection and maintenance, and shall comply with this specification as a minimum, or with local regulations whichever are the more stringent.

11.4 Service Conditions

Unless otherwise stated, the heater control panel shall be suitable for outdoor in classified location near the tanks. The heater control panel shall be located outdoor and be designed to





withstand ambient temperatures and prevailing environmental conditions, e.g., salifierous, corrosive or hazardous atmosphere (area classification), as stated in the Requisition.

Following ambient conditions apply:

• Maximum ambient air temperature : 54 deg. C

• Average room air temperature : 24 deg. C

• Maximum temperature inside enclosure due to solar radiation. : 85 deg. C

• Minimum ambient air temperature : 0 deg. C

• Relative humidity not exceeding : 100%;

• Altitude not exceeding : 1000 m

If a transformer forms part of the supply package then this shall be located in a safe area and shall be designed in accordance with specification 732/ELE/SPC/001.

11.5 Performance Requirements

RATING

Heaters shall be designed to operate reliably at the maximum voltage and shall be capable of delivering the stated output power at minimum rated voltage.

Unless otherwise specified in the Requisition, the Manufacturer shall calculate the power required for all the design cases stated and shall include a positive 10% performance margin.

In order to enhance reliable operation, the thyristors employed shall be sized so that the maximum current flowing through them shall not exceed 70% of their continuous rated current.

The maximum watt density on the element surface shall be selected to ensure that there is no degradation of the process fluid/gas.

Manufacturer shall verify both the element surface temperature and the pressure drop across the heater (at all operating conditions) by using an industry recognized and proven process design simulation package such as HTFS TASC, or an equivalent software package.

NOISE LIMITS

The sound pressure level measured at one metre distance from the heater panel, at any position, shall not exceed 70 dB(A) at any load between zero and the rated output of the unit.

If the above values are unobtainable without the use of absorptive materials, precautions shall be taken to limit their effect on cooling, dust deposits and fire hazards.





ELECTROMAGNETIC COMPATIBILITY

The heater panel shall be suitably screened to optimize electromagnetic compatibility (EMC). Any electromagnetic disturbance generated by the heater panel and its individual components shall not exceed a level which would affect the correct operation of either radio or telecommunications equipment. In addition, the heater panel shall have an adequate level of intrinsic immunity to external electromagnetic disturbance to enable it to operate as intended.

To achieve this, the heater panel shall comply fully with the requirements for EMC immunity as defined in the CENELEC standard EN 50082 part 2 and EMC emissions as defined in CENELEC standard EN 50081 part 2 and in IEC 61000-6-2 and IEC 61000-6-4.

RELIABILITY

The heater panel and heater elements shall be so designed and constructed to provide an estimated time to failure (ETTF) of 10 years for the heater elements. The manufacturer is required to demonstrate, either by calculation or by field evidence, that this requirement is met.

The design and layout of the control panel shall be such that the mean time to repair (MTTR) is no greater than 4 hours given full availability of spares and technically competent staff.

11.6 Construction Requirements

11.6.1 Heater Elements

Tubular heater elements shall be constructed from 80/20 Ni Cr resistance wire surrounded by compacted magnesium oxide powder, designed to minimize peak inrush current.

The element shall include an overall sheath tube made from material providing corrosion/erosion resistance suitable for the application. Provision shall be made to prevent water ingress into the heater element.

The preferred method of sealing the sheath is by means of a mechanical bushing with “bite” couplings.

However certain process applications require alternative construction methods, i.e., a welded design. If an alternative method is to be used, then the prior approval of the COMPANY/CONSULTANT shall be sought.

The Manufacturer shall supply suitable and sufficient supports to prevent bending of heater elements and flow induced vibration.

The number and length of elements shall be in accordance with the Manufacturer’s design, provided it is consistent with the other criteria set forth herein, or in the Requisition.

The required unheated element length shall be based on the maximum allowable temperature inside the terminal box (max. 65 deg. C), as well as the space inside the heater with restricted flow.





Spare heater elements shall be installed, but not connected. All spare elements shall be fitted with wires of sufficient length to connect the element to any bus bar in the event of their use. The spare wiring shall be identified accordingly and connected to a suitable earth connection. The minimum spare element requirement is 10% of the total number of elements required to fulfill the operational duties of the unit.

11.6.2 Over-Temperature Devices

Heater elements shall be protected against over-temperature by means of at least two temperature-sensing devices. The temperature sensing devices shall be RTD, PT100 devices. The devices shall be clamped or welded to the sheaths of different elements and located in an area of highest anticipated sheath temperature. Temperature sensing wiring shall be brought out to a separate terminal box with the same degree of protection as the main terminal box.

Thermocouple material shall be chromel-alumel and of a swaged sheath mineral oxide construction.

The thermocouple sheath shall be of the same material as the heating element sheath with a minimum wire size of 0.75 mm2. Thermocouple wires extending from the sheath shall be hermetically sealed in the head.

11.6.3 Main Terminal Box

The main terminal box shall be suitable for use in the environment described in the Requisition and shall have a minimum ingress protection rating of IP 66 according to IEC 60529. The material of construction shall be type 316 stainless steel or approved equal.

When installed in a hazardous area, the construction of electrical equipment shall comply with the requirements of the relevant parts of IEC 60079. The terminal box shall have type protection “e” unless otherwise specified.

The spacing between opposite polarity terminals shall not be less than the minimum allowed by IEC 60079-7. Separate earth terminals shall be provided inside and outside the terminal box.

The internal connections within the main terminal box shall be copper and of sufficient size, strength, and configuration to enable a solid connection of the supply cables without excessive stress on the conductors.

The Manufacturer shall consider the need for a space heater in the terminal box. If installed, the space heater shall be controlled from the heater control panel and sized so that the maximum allowable air temperature inside the terminal box (65 deg. C) cannot be exceeded.

The heater elements shall be star or delta connected depending upon the size of the load and shall be specified by the Manufacturer. Neutral linking for star connected loads shall be done inside the terminal box.





11.6.4 Control Panel

11.6.4.1 Enclosure

The entire assembly shall be installed in a freestanding sheet steel control panel, located outdoor. The minimum degree of protection shall be IP 66 as defined in IEC 60529 without considering floor as a part of the enclosure. The control panel shall be provided with lockable hinged doors.

11.6.4.2 Cooling

The control panel design should provide sufficient component spacing to allow cooling by natural air circulation.

However if natural ventilation is deemed to be inadequate, then forced draft fans may be applied. In this case, two 100% capacity fans shall be provided, each powered and alarmed separately. The control of the fans shall be such that the fans operate only when the heater is energized. The expected lifetime of the fans and their drivers shall be six years without any maintenance required.

If installed, the forced draft system shall be equipped with a suitable dust filter and an air guiding system such that only the heat sinks are cooled and the warm air is directly guided to the outside of the panel. Dust filters shall be easily cleaned from outside the cabinet.

11.6.4.3 Access

Items requiring access for maintenance, such as cooling fans, shall be accessible from the front of the unit. Any form of maintenance requiring rear access shall clearly be identified in the documentation.

All live terminals of door-mounted equipment having a maximum (peak) voltage of greater than 24 V shall be shrouded or otherwise protected by barriers to a degree of protection of at least IP 20. Barriers shall be of rigid insulating material, yet transparent to enable the screened components to be identified.

All live terminals of equipment and components within the enclosure shall be similarly protected by barriers or shrouds to a degree of protection of at least IP 20. Unless adequately recessed within the enclosure to prevent inadvertent contact or short circuit by personnel while performing any standard operations or unit maintenance.

Protective relays shall be mounted in such a way that their settings and adjustments can easily be checked and/or corrected.

11.6.4.4 Earthing

A copper earth rail (25 mm X 5 mm), with a suitable number of earthing bolts or screws, shall be provided adjacent to the external cable glands to facilitate termination of cable earth braids or armouring. Individual connections for all earth wires shall be provided. The earth bar shall be connected to the cabinet frame, effectively bonding the entire cubicle.





The enclosure shall also be fitted with an external earth point (M10 bolt) that is connected to the main earth rail.

Electrical conductivity between the exposed, non-current carrying conductive parts of the heater panel components and the enclosure, and between the enclosure and the earth rail/earth stud, shall be such as to maintain effective continuity of protective circuits. Earth bonding conductors shall be provided between enclosures and doors and between the gland plate and main earth rail. The neutral of the heater output shall be solidly earthed.

11.6.4.5 Terminals

Rail mounted terminals of equipment and components shall be identifiable by numerical or alphabetical markings in accordance with the Manufacturer’s drawings. All cabling shall enter the panel from below. Terminals for incoming and outgoing circuits shall be grouped together at the same height as the power terminals.

Separation plates shall segregate terminals of different voltage levels.

The Manufacturer shall provide undrilled bottom gland plates.

The terminals for the power cables shall be located so that a free space of at least 400 mm shall remain between the gland plate and the lowest terminal.

Terminals of input and output supply cables shall be clearly and uniquely marked to indicate the nominal system voltage and the phase/polarity of the supply.

The identification of terminals shall be in accordance with IEC 60445.

11.6.4.6 Marking

The following information shall be inscribed on a corrosion-resistant, indelible data plate attached to the unit enclosure by screws:

• Purchaser’s order number;

• Year of manufacture;

• Name of manufacturer;

• Type and serial number of unit;

• Nominal input current and voltage;

• Nominal output power

Additionally, major panel components shall be identified with labels attached to mounting plates wherever possible. All such labels/nameplates shall be of corrosion resistant material with indelible inscriptions in the language specified in the Requisition.





11.6.4.7 Finish

All equipment shall be adequately protected against corrosion and appropriate for the environment of installation. The paint systems employed shall comprise as a minimum one coat of primer and two coats of oil resistant paint.

The colour of external surfaces should be light grey RAL 6035.

The fully assembled panel shall be mould and vermin-proof and shall be treated in all respects to provide lasting durability under the specified service conditions.

11.6.4.8 Electrical Components

All electrical components shall comply with relevant IEC standards.

Main circuit switches (mechanical) shall comply with IEC 60947 and be of the independent, manually operated, air-break type for continuous duty and shall comply with utilization category AC21.

Contactors shall comply with IEC 60947-4-1 and be rated for uninterrupted duty and intermittent duty of at least class 1. The utilization category for AC contactors shall be AC-1.

General purpose fuse links shall be type gG and comply with IEC 60269.

11.6.4.9 Internal Wiring

Secondary wiring inside the panel shall have a cross section of at least 1.5 mm2.

All wiring shall be stranded. Stranded wiring shall be terminated in suitable cable lugs or wire pins. Earth wires shall be green/yellow striped. Two wires connected under one terminal is not allowed unless the terminal is specifically designed for this purpose.

Wiring between terminals shall be continuous without wire joints. Wiring shall be provided with wire markers at both ends in accordance with identifications as used on Manufacturer’s drawings.

Fuses shall be screened from each other and arranged so that they can be safely removed. Busbars shall be insulated and, where required, designed to withstand the upstream fault level.

11.6.5 Measurement, Protection and Control Equipment

11.6.5.1 General

The heater panel shall incorporate all the necessary equipment to enable operation, protection and control of the heater in accordance with this and to safeguard the unit and its components from the consequences of internal and external short circuits, over voltages and any main or control circuit malfunctions, howsoever caused.





Operating, status and diagnostic indications shall be provided by bunched light-emitting diodes (LEDs). Each LED/alarm circuit shall have in-built test facilities. Failure of an LED shall not cause maloperation or affect the correct functioning of the remote common alarm signal. Indication by means of filament lamps is not acceptable.

11.6.5.2 Measurement

Following panel mounted instruments shall be provided on the front facia of the panels.:

• Incoming voltage - Voltmeter with selector switch;

• Output current - Ammeter with selector switch.

11.6.5.3 Protection and Alarms

The status of the alarm and protection functions shall be visually verifiable by appropriate indicators.

Alarms associated with trip functions shall be hand reset.

The following alarm and protection functions shall be provided as a minimum:

• Earth fault trip;

• Fan failure alarm;

• Thyristor over-temperature alarm;

• Thyristor over-temperature trip;

• Heater element over-temperature alarm;

• Heater element over-temperature trip.

Thyristors shall be protected against overload by means of ultra rapid fuses.

Core balance instantaneous ground fault protection with a maximum sensitivity of 500 mA shall be provided. The sensitivity value shall be adjustable.

The heater elements shall be protected against over-temperature by means of temperature sensing devices located on the outside of the elements.

Current limitation shall be provided where deemed necessary by the Manufacturer.

A ramp unit shall be provided in order to protect the heater or power system from damage that could occur as a result of electrical, mechanical and thermal shocks caused by direct full load switching.

In general, protection relays and services shall be provided with indicators and manual reset facilities on the front panel. Earth fault and over-temperature trip reset switches shall be





tamper proof. Trips actuated by protective devices shall act instantaneously and shall trip the main contactor under all conditions.

Voltage-free make and break contacts shall be provided on all protective relays for remote common alarm purposes. Make contacts shall be wired in parallel and break contacts shall be wired in series to outgoing terminals.

11.6.5.4 Auxiliary Equipment

All components for controlling, measuring, and protection shall be logically grouped in the control panel. The following accessories shall be provided as a minimum:

• Main incoming switch shall conform to IEC 60947-1, with a door interlock and red indicator lamp;

• Main contactor with off/on auxiliary switch and terminals for remote off/on switching.

12. INSPECTION & TESTING

12.1 Inspection & Testing (Non-Electrcal)

• The inspection shall be done by a reputed third party agency.

• The heating element shall be thoroughly dried out by vendor before sealing.

• Positive material identification (PMI), vendor shall ensure that all alloy steel and stainless steel material are properly identified and finally check tested by a PMI analyser before dispatch of equipment.

• In addition to stamping, the specifications & manufactures symbol as specified in ASME material specifications, on one of the ends the size of the stud shall be clearly punch marked.

• Similarly the nuts shall have the size punched marked on one of the faces. In case of tapped hole the size shall be punch marked near the hole without disturbing the gasket seating area. Further for all alloy/SS metallurgy bolts & nuts shall also be identified by distinct colour marking at the stud end/bolt side face.

• Vendor shall carry out various tests as per applicable codes/standards. Any or all test including hydro test shall be at purchaser’s option carried out by it’s authorised representative or certifying agency.

• Equipment shall be subjected to inspection by authorized representative of purchaser or certifying agency and shall have access to inspect the equipment at any stage during manufacture. During inspection, material certificates, shop test data, certificates for bought out components and other relevant information shall be furnished so as to ascertain that the specifications and quality is complied with.





12.2 Inspection & Testing requirements (Electrical)

12.2.1 General

Before leaving the Manufacturer’s works, all equipment shall hve been inspected and tested and the results recorded in test reports.

If the Manufacturer’s normal test arrangements are not applicable or the Manufacturer is unable to perform the specific tests according to design specifications, then the tests to be performed shall be subject to agreement between the Manufacturer and the COMPANY/CONSULTANT before the order is placed.

12.2.2 Quality Assurance

The Manufacturer shall carry out all operations concerning the production of the heaters/systems to a recognized quality system, e.g., ISO 9001, details of which shall be provided to the COMPANY/CONSULTANT.

12.2.2.1 Factory Acceptance Tests

In general, all testing shall be carried out fully in accordance with this specification. The Manufacturer’s standard test protocol shall be acceptable provided it is no less stringent than that specified below. Whether the Principal or his nominee will inspect the equipment and witness the required tests shall be indicated on the Requisition and confirmed or waived at the time the equipment is offered for final inspection. Notification thereof shall reach the Principal at least two working weeks before the testing is scheduled.

12.2.2.2 Heaters

The following electrical tests shall be carried out:

• High voltage test with 1500 VAC to be carried out for 1 min.;

• Insulation test of heaters to earth with a 500 VDC insulation resistance tester;

• Continuity to be tested on each phase of the heater.

12.2.2.3 Control Panel

The following tests shall be carried out:

Temperature Rise Tests

All thyristors shall be operated for a minimum of two hours on full load current (reduced voltage if necessary) and the temperature of these components shall be measured and logged on a chart recorder.





12.2.2.4 Waveform Recording

The output current and voltage waveform is to be recorded for each heater zone/driver, for varying levels of input signal. This test is to be carried out with full load current available. A type test is acceptable for this purpose.

12.2.2.5 Insulation Test

All equipment (except instrumentation and thyristor assemblies) shall be tested at a minimum of 500 VDC.

12.2.2.6 High Voltage Test

All equipment (except instrumentation, thyristor assemblies, transformers, etc.) shall be tested in accordance with IEC 60398 with a minimum test voltage of 1500 VAC for 1 min.

12.2.2.7 Load Control Test

A load control test shall be performed to plot the control input against the power output using a load bank.

12.2.2.8 Functional Tests

All components, e.g., protective devices, alarms, etc., shall be tested to ensure that they function correctly.

12.2.2.9 Noise Tests

The control panel shall be operated at full load and sound measurements taken at 1 m distance to ensure the maximum noise level is no greater than 70 dBA.

12.2.2.10 EMC Tests

The equipment shall be subjected to tests described in IEC 61000-4.

12.3 Site Acceptance Test

A full load test of the heater in its service condition shall be carried out to confirm the design output. In addition, interfaces to other connected systems shall be tested with particular emphasis on control, protection and alarm systems. The Manufacturer/Vendor shall submit a test plan detailing all such tests and showing required interfaces with third parties, for approval by the COMPANY/CONSULTANT.

13. SPARES

Vendor shall include for the following as mandatory spares:

• 10% spare elements (minimum 1) shall be in-built and electrically connected.

• 10% copper links for connections to bus bars complete with bolts/nuts.





• 200% gaskets (excluding those required for assembly, testing and dispatch).

• 20% studs with 2 nuts each (minimum 4 studs and 8 nuts of each size).

• Spares for start-up and commissioning.

Any additional optional spares required for two years of operation including spares for control system and any special tools required for maintenance/operation along with details shall be indicated.

14. VENDOR DATA REQUIREMENTS

In addition to the Vendor data requirements stipulated in the Requisition and specifications, the following shall also be submitted along with the offer: -

• Maximum sheath temperature, maximum temperature of the shell, maximum heat flux*, rating of each heating element in kilo watts, pressure drop, heat transfer area, tube/sheath size, thickness and material of construction, minimum tube bend radius, duly filled and complete thermal data sheet.

• Set temperatures for thermocouples proposed and auto-ignition temperature for fluid heated.

• Vendor shall furnish complete configuration of heater & thyristors being offered in his bid.

• Vendor in his offer must indicate dependable element operating temperature.

• Vendor to furnish electric heater operating & maintenance instructions after award of order.

• Catalogues/specifications/details for skin thermocouples.

• Vendor must ensure that all the documents are thoroughly checked and approved at their end by at least one competent engineer and design office in charge before submitting for review.

(*Maximum heat flux, quoted by the vendor, must be supported by vendor’s reference list of electric heaters for identical services and vendor’s quoted heat flux needs to be approved by the client.).

15. GUARANTEES AND PERFORMANCE

The MANUFACTURER shall guarantee, in accordance with general conditions, that the equipment shall meet the performance conditions specified in this specification and the data sheets.