Technical Guide Exothrmic Welding in Railways

SPECIFICATION NUMBER: TI/SPC/OHE/EXTHRMBOND/010(04/10)

GOVERNMENT OF INDIA MINISTRY OF RAILWAYS

TECHNICAL SPECIFICATION FOR

Exothermic Welding connection for Bonding, Earthing/Grounding

ISSUED BY

TRACTION INSTALLATION DIRECTORATE RESEARCH DESIGN AND STANDARDS ORGANISATION

MANAK NAGAR, LUCKNOW 226 011 (INDIA)

(For official use only)

of 17 pages Effective from 01.04.10 Spec No. TI/SPC/OHE/EXOTHRMBOND/0100(4/10)

SPECIFICATION NUMBER: TI/SPC/OHE/EXOTHERMBOND/0100(4/10)

FOR EXOTHERMIC WELDING CONNECTION FOR BONDING &

GROUNDING

Amendment Date of Amendment Total pages including drawings

Amendment/Revision

0 NA 17 First issue

PREPARED CHECKED BY APPROVED BY SIGNATURE -Sd/- -Sd/- -Sd/-

DATE 8.4.10 8.4.10 8.4.10 DESIGNATION ADE/OHE-D DTI-MRVC ED/TI-Co.

COPY NUMBER

ISSUED BY ---------------------- SIGNATURE -------------------- DATE -------------------

ISSUED TO --------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

NOTE: This specification is property of RDSO. No reproduction shall be done

without permission from DG (TI), RDSO. This specification is not for general use.


SPECIFICATION NUMBER: TI/SPC/OHE/EXOTHERMBOND/0100(4/10)

INDEX

ITEM NO. HEADING PAGE 1 Forward 3 2 Scope 3 3 General and other requirement 3 4 Welding Material 5 5 Welding Tool 5 6 Marking 7 7 Packing 8 8 Acceptance Criterion 8 9 Training/Instruction Manual 9 10 Information to be supplied by the purchaser 9 11 Appendix-I(Sheet 1 to 2) 10 to 11 12 Appendix-II(Sheet 1 to 3) 12 to 14 13 Appendix-III(Sheet 1 to 3) 15 to 17


Specification No. TI/SPC/OHE/EXOTHRMBOND/0100 (04/10)

For Exothermic Welding Connection for Bonding & Grounding

1.0 Forward

This specification basically covers the technical provision & requirements and does not include all other necessary provisions for the contract.

2.0 Scope 2.1 This specification covers the requirements and acceptance criterion for weld

material, welding tool and tool kit, bonds/track bond wires for making permanent electrical bond connection between two conductors.

2.2 The intent of this specification is to ensure the production of properly formulated

and tested weld material for making traction bond connection to/between the traction rails/track and with OHE structure for electrical continuity with adequate bonding strength. The prime concern must be focussed on the necessary design and quality requirements to achieve adequately strong weld connection, which shall eliminate in service connection failure under severe climatic and adverse field conditions.

2.3 These weld materials including tool kit shall be useful in following railway

application on 25kV electric traction system.

(a) Traction bond connection to rail & OHE structures route. (b) Traction rail continuity connection. (c) Earthing connections like at TSS, SP/SSPs, SCADA/RTU and other

important electrical installations. (d) Bus bar connections etc. (e) Copper to copper, copper to steel connection. (f) Important bonds which are not disturbed during track relaying. (g) Sections where 90UTS rails have been provided. (h) Theft prone areas.

3.0 General and other requirements 3.1 Manufacturers should have a good quality assurance system to guarantee the

product e.g. ISO 9001 2000 assessed by authorised agency.

of 17 pages Effective from 01.04.10 Spec No. TI/SPC/OHE/EXOTHRMBOND/0100(4/10) 3.2 Manufacturers should provide sales reference list that shows type, delivery,

customer and address of customers, details of catalogue and type test reports & approvals of the product.

3.3 Manufacturer should submit approval & test reports, both internal and external from authorised/reputed test houses as per National/ International Standard.

3.4 The welded connection should pass the following parameters if tested as per

IEEE-837:

Mechanical Pullout, Electromagnetic force, Resistance, Freeze-thaw cycling, Salt Spray test, Corrosion-acid test and Fault current test.

3.5 Welding material along with tool kit shall be capable of providing a permanent bonding connection involving copper or aluminium or steel as specified by the purchaser. The final bond shall be achieved in such a way that homogeneous molecular bonding of two involved metals takes place perfectly.

3.6 Exothermic Welding process should be: A steady burn, No pops, No drastic colour

changes (white hot colour during burn, turns orange as the reaction stops and the molten metal grows orange).

3.7 Welding connections should be without voids or pinhole, and no porosity should

be detected. The process shall be consistent and continuous. 3.8 It shall be permanent, solid metal, maintenance free connection and shall not be

affected by high current surge. 3.9 It shall not loosen or corrode at the point of weld. There shall be no additional

contact surface or mechanical pressures involved. 3.10 It shall be vibration proof and corrosion free electrical connection. 3.11 It shall not brittle with age and shall be able to sustain physical impacts, which

may be experienced under the field conditions. 3.12 Electrical resistance and other properties shall not deteriorate with ageing and

under severe Indian climatic conditions.

of 17 pages Effective from 01.04.10 Spec No. TI/SPC/OHE/EXOTHRMBOND/0100(4/10) 3.13 It shall have a current carrying capacity equal to or greater than that of the

conductors.

3.14 Life of the joints itself shall not be less than 10 years irrespective of life of conductors, equi-potential earth bus bars or Ground Rods used.

4. Welding Material

4.1 The weld material shall be designed for two specific types of jointing application

as mentioned above (a) rail welding application and (b) earthing & bonding application.

4.2 It shall not contain phosphorous or any caustic, toxic or explosive substance. For

rail welding application, the welding material should not contained tin besides the above cited elements. Its components shall not be volatile or sensitive to shock, nor shall they be capable of spontaneous ignition or ignition by friction.

4.3 The reaction of the weld material shall be completed within 10 seconds and on

completion of jointing & bonding process no un-reacted material shall remain. The resulting weld nugget shall be free of dissolved gases or low boiling point elements, e.g., small voids or blisters on the surface.

4.4 Weld material shall provide a final bond with minimum tensile strengths of 40,000

psi tested using ASTM ES-94a (Test Methods for Tension Testing of Metallic Material). As a guideline, 3 samples of diameter test specimen & 5 long of weld material shall be cast in the form of bars using 250 gms of weld metal powder and tested as cast for tensile strength or as per any other standards accepted by the purchaser on any tensile testing machine of adequate capacity.

4.5 The weld material for traction bond and stud welding for rail application shall be

free from tin. As presence of metallic tin allows for wetting of rail surface and provides for unnecessary penetration that can lead to metallurgical damage to the rail.

4.6 The weld material for earthing & bonding application shall be UL listed and shall

be tested as provision of IEEE-837 by NABL/ILAC Member labs. The manufacturer should have latest UL certification for their facilities and it should be regularly extended after the expiry of the certification to ensure genuineness.

5. Welding Tool 5.1 It shall be suitable for bonding as per the sizes specified in Appendix-I to III for

bonding Equi-potential Earth Bus Bars (EEBB) to ground rod, protective conductor etc.

of 17 pages Effective from 01.04.10 Spec No. TI/SPC/OHE/EXOTHRMBOND/0100(4/10) 5.2 The tools shall be of lightweight and whole kit containing bonding material; weld

materials and tools shall be easily portable by one person from one spot to another. 5.3 It shall be possible to remove it immediately after jointing or whenever required. 5.4 In-built protection shall be available against any flash generation during weld

process, which is injurious to user. 5.5 Tools required for high temperature working shall be of graphite or suitable

material so as to be capable of working at temperatures sufficiently higher than the temperature conditions achieved during jointing.

5.6 Any ignition tool included in the tool kit shall be portable and easy to operate.

Ignition time shall be very quick and shall work efficiently even under damped weather conditions.

5.7 For quality and safety, moulds, bonds, weld material and other tools shall be

supplied as one unit unless otherwise mentioned by the purchaser. 5.8 For integrity and safety of the connection, the weld metal, moulds and clamps

should be of the same manufacturer. 5.9 Whole weld kit shall be light, portable, self contained, simple in working and shall

require very little time and skill to make perfect connection every time. 5.10 Tool kit shall give consistent quality bond for at least 100 joints for non-tensioned

joints. 5.11 Welding connection shall be completed within 10 second and in such a way that

amount of heat (in calories or BTU) required for final connection causes no damage to conductors and its insulation and to metal surfaces.

5.12 Power operated tools, if any, for carrying out weld work shall have the provisions

for its working on 110/230V a.c. and portable battery. 5.13 Suitable means and guidance shall be provided to prevent equipment failures

connected through rails due to flow of electric current during weld process. 5.14 Complete jointing process including preparatory work shall not take more than 2 to

3 minutes per bond under normal working conditions, to avoid requirement of traffic line blocks.

of 17 pages Effective from 01.04.10 Spec No. TI/SPC/OHE/EXOTHRMBOND/0100(4/10) 5.15 If any melting of metal is involved in the jointing process, it shall quickly solidify

so that system is immediately available for charging. 5.16 Once ignition is started it shall not result in imperfect bond/joint. 5.17 Welding kit shall comprise of weld material, bonding material & tool kit. It shall be

supplied in sufficiently strong carry-bag for easy transportation by the Maintenance people.

5.18 Weld material shall not contain hazardous ingredients sufficient to constitute a

hazard & weld process shall not result in any surface irregularities. 5.19 Welding material shall have a minimum shelf life of five years, when stored in a

reasonable storage condition, so that material can be used without any testing within this period for optimum results.

5.20 Detailed training manual including working instructions for the user for achieving

best results shall be supplied along with each tool kit. Necessary instructions for protection of workers shall be incorporated if process is harmful to human beings. Whenever required, necessary guidance shall be given by manufacturer (or) manufacturers trained representative to user at site.

5.21 In case of any mishandling or accidental situation, details of suggested first-aid

measures shall be given.

5. MARKING

6.1 Each package/ box of welding material/bonds shall be properly marked for easy identification and shall be stamped with the lot number.

6.2 Carton shall have part number printed, contents, size and weight shall also be

marked. 6.3 To maintain traceability, batch and/or lot control identification shall be marked on

packages prior to despatch of consignment. 6.4 Month and year of manufacture shall be marked on the container. 6.5 For materials having a limited shelf life, a clear expiry date shall be marked before

which material is to be consumed for best results. 6.6 All the sizes, weight and other dimensions of packed items shall be marked with an

accuracy of 5%. The marking shall be distinctively in indelible printing-cum-indented/embossed form.


7. PACKING 7.1 The containers for weld material shall be moisture resistant and shall be packaged

to prevent damage, separation or spillage during shipping. 7.2 The weld material including starting powder should packed in the waterproof

transparent plastic. The starting powder should put on the bottom of the tube. 7.3 The weld material shall be pre-measured for specific applications suitably marked

and packaged together in a non-absorbing container. 7.4 It shall be packed in such a way that it shall not loosen during transportation and

normal handling. 7.5 Container and caps shall be marked with unit size and show item number,

manufacturer, and manufacturing date. 7.6 All the contents like weld material, bonds, tools etc. shall be packed individually

and then repacked in a bigger single pack. 8. ACCEPTANCE CRITERION

Following shall be provided by manufacturer for evaluating the product before it is considered suitable for its applications on Indian Railways -

8.1 Remarks/compliance shall be given for all provisions of this specification. 8.2 Details of welding process, properties and chemical composition of weld material,

its energy content shall be provided. 8.3 Standards followed in manufacturing and testing of products including weld tools. 8.4 Details of analysis carried out by manufacturer, as a routine test on raw materials,

final product and Quality Assurance Testing shall be made available for evaluation or as and when asked by the purchaser.

8.5 Laboratory test results including field observations for verification and validation

of all results of Quality Assurance Testing & Engineering specification. 8.6 UL listing certificate for the weld connection along with the test report as per the

provisions of IEEE-837 by NABL/ILAC Member for welding material required for earthing and bonding other than track.


8.7 Documents to ensure nil effect of weld process on EEBB or ground rod surface or

on rail surfaces as the case may be. 8.8 Details of substances hazardous to health of workers and precautions to be taken

during process. 8.9 Performance feedback and acceptability of same product on Indian Railways and/or

other Railway system abroad/power transmission and distribution system etc. Product must have been in use for similar applications for at least 2-3 years.

8.10 Manufacturer shall arrange for any other test and/or documents considered

necessary by the purchaser to establish quality and performance of the product. 8.11 Two copies of training/instruction manual. 8.12 Guarantee for supply of spares and consumables for 10 years. 8.13 Suppliers/manufacturers with a new product complying the requirements of this

specification except Clause-8.8 above may be considered for educational/ developmental orders only.

9.0 Training /Instruction Manual

The supplier shall impart adequate practical training to field staff to operate the exothermic welding kit at site. The training shall cover the procedures & safety measures to be adopted by the Railway staff while performing the welding process. Supplier shall also supply two copies of Training/Instruction Manual along with each exothermic welding kit.

10.0 INFORMATION TO BE SUPPLIED BY THE PURCHASER 10.1 Type of applications. 10.2 Quantity (item-wise) for bonds, weld material (for different applications) and tools

required. 10.3 Sizes and length of bonds, Equi-potential earth bus bar (EEBB), protective

conductors & ground rods and dia of all the cross sections to be bonded and all relevant sizes to be used for jointing surface.

10.4 Inspecting Agency for acceptance of material.

***


Appendix-I (Sheet-1)


Appendix-I (Sheet-2)


Appendix-II (Sheet-1)


Appendix-III (Sheet-1)

Technical Guide Exothrmic Welding in Railways

Documents

Transcript of Technical Guide Exothrmic Welding in Railways