STANDARD SPECIFICATION

FOR

SKIN EFFECT HEAT TRACING SYSTEM

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0 6.9.10 Issued for use SKV BKP PKBRev. Date Description Prpd. Chkd. Appd.

IOT Design & Engineering Limited

ELECTRIC HEAT TRACING

Std. / Doc. Number Rev.

00000-06-TS-017 0

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CONTENTS Page

1. SCOPE........................................................................................................................3

2. REGULATIONS AND STANDARDS..................................................................................3

3. OPERATING ENVIRONMENT........................................................................................4

4. SYSTEM DESIGN REQUIREMENTS.................................................................................4

4.1 General..........................................................................................................4

4.2 Heat Loss and Tracer Input...............................................................................5

4.3 Tracer Cable Requirements..............................................................................6

4.4 Piping Trace Heating Systems...........................................................................6

4.5 Tank and Vessel Heat Tracing Systems..............................................................7

4.6 Instrument Tracing Systems.............................................................................7

4.7 Temperature Control......................................................................................8

4.8 Power Supply.................................................................................................8

4.9 Distribution Boards.........................................................................................8

4.10 Nameplates..................................................................................................8

4.11 Circuit Tags....................................................................................................9

5. INSTALLATION REQUIREMENTS....................................................................................9

5.1 General..........................................................................................................9

5.2 Heat Tracing Cable Installation.........................................................................9

5.3 Cable Attachment...........................................................................................10

6. DRAWINGS AND DATA................................................................................................10

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6.1 Heater circuit design drawings..........................................................................11

6.2 Electrical Wiring Diagrams...............................................................................11

6.3 Field Routing Drawings....................................................................................11

6.4 Local Panel Drawings.......................................................................................12

6.5 Installation Drawings.......................................................................................12

6.6 As-Built Correction to Drawings........................................................................12

6.7 General Installation, Operating and Maintenance Literature................................12

7. INSPECTION AND TESTING...........................................................................................12

APPENDIX A: STANDARDS

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1. SCOPE

This specification covers the requirements for the design, material selection, installation and testing of the Skin Effect Heat Tracing System for the 8 Inch 1.5Km Sulfur Line.

Seller shall provide the following services when specified:A. DesignB.Installation of heat tracingC.Installation of transformer(s)D. Installation of Distribution Board(s)E. Installation of wiring and conduit to heat tracingF. Installation of thermal insulation and weather barrierG. On site training

CODES AND STANDARDS – GENERAL

The Skin Effect heating system has been designed in accordance with the following codes and standards including listed in appendix A.

INTERNATIONAL ELECTROTECHNICAL COMMISSION (IEC) or equivalent

IEC 60076 Power TransformersIEC 60044 Instrument TransformersIEC 60073 Basic and Safety Principles for Man–Machine Interface, Marking andIdentification - Coding Principles for Indication Devices and ActuatorsIEC 60529 Degrees of Protection Provided by Enclosures (IP Code)IEC 62086-2 Electrical Apparatus for Explosive Gas Atmosphere – Electrical ResistanceTrace Heating – Part 2. - Application Guide for Design, Installation and Maintenance

For the purposes of this specification, the word "should" shall be replaced with the word "shall" wherever it appears in the above referenced standards.

All components and the complete assembly shall be approved by an approved certifying authority and shall bear a label indicating compliance. If any equipment is not available with such labeling, the Seller shall provide written documentation to that effect with the proposal.

Any conflict between the referenced documents shall be identified to the Buyer in writing for resolution. In general, when resolving conflicts, the following order of precedence shall apply.

Data Sheet and Drawings Purchase Order This Specification Referenced Standards

3 SYSTEM DESIGN REQUIREMENT

This standard specification shall be read in conjunction with the Basic Engineering Design Data :-

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Site conditions Design Temperatures Power Supply voltages Enclosure IP ratings Insulation Material and insulation thickness- Refer Insulation Specs

The design shall be based on continuous and reliable service, safety to operators and all equipment. It shall have least maintenance requirements and inter-changeability, wherever applicable.

The Skin effect Heat Tracing System offered shall ensure continuous running of this critical application.

The method of calculation of heat loss and released parameters shall be as per guidelines given in the standards. The losses from each part of the surface shall be calculated using the appropriate formula and added together to determine the total heat loss. For the sulfur line a minimum design margin of 25% shall be considered on the rate of heat loss calculated. Calculations shall be furnished for owner's/ Consultant’s review.

The surface temperature of Heat tracers / Electrical equipment intended to be used in hazardous area shall not exceed T3 temperature class. All electrical hardware which is installed in hazardous area shall be suitable for hazardous area zone 1 & 2 gas group II A / II B unless otherwise specified.

It will be the sole responsibility of the Heat Tracing Contractor to optimize the entire Heat Tracing System.

Power cables from Local Distribution to the heat tracer shall be sized to limit the voltage drop to maximum 3 % under full load condition, including maximum heater output rating at operating conditions.

Further, the selected cable size shall also be adequate to carry the maximum anticipated heat tracer start up current while the heating device is at minimum temperature.

3 core-armoured cables shall be used for power supply to heat tracer for single-phase circuits. (2 cores for phase and neutral and third core for earth conductor).

3Core x 1.5Sqmm armoured RTD cable suitable for 3 wire temperature sensor (PT 100) shall be provided.

Suitable armoured communication cable shall be provided between various temperature scanners located in LDP & operator terminal located in control room.

SKIN EFFECT HEAT TRACING SYSTEM

The skin effect heat tracing system is generally used for piping over 1000-1200Mtrs. The system concept is based on skin and proximity effects.

The skin effect is caused by the current flowing in a wire pulled inside a heat tube and the inner surface of the same tube. The insulated wire is connected to the heat tube at the end termination and the voltage source is connected between the heat tube and the insulated wire at the power connection. Since the heat tube is attached to the process pipe and completely covered by the thermal isolation system, the heat is transferred to the process pipe.

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Skin Effect Heating System shall be mainly composed of specialty power transformers, special skin effect electrical conductors installed inside a ferromagnetic heat tubes, load and control equipment and all necessary installation accessories.

System Design

Design of skin effect heating system shall be by manufacturer and shall be as follows:-

a. Heating System shall be designed to produce even heating along entire length of pipeline to offset heat losses stated in design conditions.

b. Design of Ferromagnetic heat tubes and special electrical conductors that shall provide required amount of heat.

c. Design shall include temperature / power control, monitoring and over current protection devices needed for heating systems.

Skin Effect Conductor

The Skin Effect conductor shall be insulated with a high temperature (260 Deg.C minimum) special PFA dielectric in such a manner that minimal air space exists between conductor strands and extruded dielectric.

Heat Tube

Heat tube shall be seamless SCH 40 A106 GrB PE. The size of the heat tube shall be suggested by the supplier. .

Pull Boxes

Pull Boxes and splice boxes will be located along the line and shall allow the cable trouble shooting and replacement without removal of the pipe insulation.

Temperature Control

The control of the skin effect heating system shall be accomplished by solid-state temperature controls with RTDs as sensors. Temperature, voltage and current values shall be monitored and over current with protection relays shall provide fault trips and alarms

4.8 Power Supply

The heat tracing system shall be supplied from 415 V AC 3 phase 50 Hz switch board. Switchboard will have one dedicated breaker feeder for heat tracing system to cater to the total load requirement.

4.9 Switchgear

The SKIN Effect Contractor shall provide necessary switchgear from the point after the main incoming power supply for the heating system. It should comply with all the relevant standards and specifications. Reference should be made to the project LV switchgear specification and HV switchgear specification. An Industrial grade HMI shall be part of SKIN effect system through which the entire parameters including transformers, LBUs, HV

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Panels etc shall be viewed and controlled. All the parameters shall be communicable to the DCS through RS 465 Modbus link.

5 INSTALLATION REQUIREMENTS

5.1 General

The Seller is required to provide installation drawings for all components of the Skin Effect Heat Tracing System.

The installation shall be in accordance with all project drawings and installation drawings. The installation shall also be in accordance with Seller's recommendations unless modified herein. Any conflicts in these documents shall be brought to the attention of the Buyer, for a resolution.

The installation of electrical heat tracing systems requires special skills and precautions that may not be commonly known. Prior to the installation of any component of the heat tracing system, the Seller shall be responsible for familiarizing all people involved with the installation and testing requirements.

5.2 Skin Effect Installation

Skin effect heat tracing shall be installed as per manufacturers’ recommendations.

5.3 Skin Tube Welding

The welding of Heat Tube to the product pipe shall not be in the scope of the skin effect contractor.

6 DRAWINGS AND DATA

The Seller shall provide drawings and data in accordance with:A. The purchase requisition and its attachments including "vendor drawing and data

requirements" and detailed requirements in this specification.B. Instructions to Sellers.

6.1 Heater circuit design drawings

The Seller shall furnish drawings that show each heat tracing circuit and its component devices. These drawings must be in the form of plans and details (equipment) or isometrics (piping) to readily orient the heater cables, sensors and other devices with respect to the actual installation.

The following shall be clearly indicated on the drawingsA. Process isometric number, instrument, and equipment tag number.B. Line size, insulation type and thickness, and all other design data listed in Error!

Reference source not found, and 6.5C. Electrical tracing circuit number.D. Coordinates and elevations locating the boundaries of the section traced,

process instruments on the traced line section, control temperature sensingelements, hot and cold junctions, power supply points, and other junction boxes.

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E. Representation of all flanges, valves, branch lines and valves, drains, pumpsinstruments, pipe supports, and equipment nozzles.

F. Diagrammatic representation of heater style, number of passes, and allinterconnections.

G. Length of tracer cable to be installed for wraps.H. Junction boxes included to sectionalize the tracing for isolation and maintenance, for

example, to isolate tracing for instrument transmitters, pumps, removable spools, etc.

6.2 Electrical Wiring Diagrams

The Seller shall prepare electrical wiring diagrams for the tracer installation including typical schematics for the tracer cable connection, control wiring, and local distribution board. A local distribution board schedule shall be prepared in an electronic Data Base that indicates and totals all branch circuit loads for maximum cold amp loading and design maintain temperature loading. The schedule shall include:

A. Board numberB. Circuit numberC.Heater type and lengthD. Heater Voltage and WattageE.Cold Amperage

6.3 Field Routing Drawings

The Buyer will prepare field routing drawings (similar to lighting plan drawings) before the start of cable installation. Using plot plan drawings as a background, these drawings will be prepared after tracing isometrics have been completed as above. These drawings will show the location of local electric tracing distribution boards, which have been planned for the project. The Seller will identify elevation, and locate coordinates of the heaters, sensors, and auxiliary devices on the background. Buyer will complete the drawing showing schematic runs for power and control wiring to the local distribution board.

6.4 Local Panel Drawings

The Seller shall prepare a complete layout, schematics, bill of material, and wiring diagram for the local distribution board/controller. The drawings shall show all components, including the power transformer, circuit breakers, controllers, indicators, and alarms. All outside wiring connections such as main power and common alarm shall be shown. The general arrangement drawing shall show:

A. Elevations, sections, floor plan and base layout.B. Arrangement and mounting of all components and extent of windows on the front

of the panel, door swing, and back panel.C. Location of ground and bus lugs.D. Location of terminal blocks.E. Purge system location and details (when required).F. Location of cable entries.G. Nameplate schedule.

6.5 Installation Drawings

The Seller shall prepare installation details and drawings, which define the placement of cable on piping, valves and other heat sinks, instrumentation, level glasses, pumps and other equipment, etc.

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6.6 As-Built Correction to Drawings

As-Built corrections shall be added to all drawings and to the database to reflect the changes in materials and installation.

6.7 General Installation, Operating and Maintenance Literature

Detailed literature shall be provided covering all equipment supplied, including:A. Electric heater cable description data including physical and electrical

characteristics and performance, dimensions, weights, etc.B. Recommended procedures for handling, installing, terminating, and splicing of

electric heater cable.C. Complete installation, operating and maintenance manuals including component

descriptive literature and information on handling, installing, maintaining, andtroubleshooting the equipment.

D. Reports for all factory tests performed on equipment and cable.

7. INSPECTION AND TESTING

In addition to the Seller's standard testing procedures, the inspections and tests in this section shall be conducted on each control panel assembly and on each heater cable.

APPENDIX A STANDARDS IEC- International Electro technical Commission STANDARDS

IEC 60364 Electrical Installations

IEC 60398 General Test Methods for Industrial Electro-Heating Equipment Second Edition.

IEC 60519-10 Safety in electro heat installations Part 10: Particular requirements for electrical resistance trace heating systems for industrial and commercial applications-Edition 1

IEC 60529 Degrees of protection provided by enclosures. (IP Code)

IEC 60800 Heating Cables with a Rated Voltage of 300/500V for Comfort Heating and Prevention of Ice Formation Second Edition

IEC TR1423-1 Heating Cables for Industrial Applications-Parti: Performance Requirements and Test Methods First Edition.

IECTR 1423-2 Heating Cables for Industrial Applications-Part 2: Constructional and Material Requirements First Edition.

IEC 61000-4 Electromagnetic Compatibility (EMC).

IEC 62086 Electrical apparatus for explosive gas atmospheres. Electrical resistance trace heating.

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Part 1 General and testing requirements.

Part 2 Application guide for design, installation and maintenance.

ISO - International Organization for Standardization

ISO 3864 Safety Colours and Safety Signs

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