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7/30/2019 12 Procedure for Coating Wrapping Rev 01
1/6
LARSEN & TOUBRO LIMITEDPAGE NO.- 1 OF 6
DATE:-05.01.2008
MSQ UP GRADATION (EPCC 1)PROJECT REV.NO.- 01
PROCEDURE FOR COATING ANDWRAPPING OF UNDERGROUND CARBON
STEEL PIPELINES.
PROCEDURE NO.-LT/MSQ/P/UG/CW/012
CONTENTS
1) PURPOESE
2) REFERENCE DOCUMENTS
3) MATERIALS
4) PROCEDURE
5) INSPECTION
6) REPAIR7) MACHINE LIMITATION
8) HANDLING OF COATED PIPES
9) SAFETY PRECAUTIONS
APPROVED BY L & T REVIEWED / APPROVED BY JACOBS
7/30/2019 12 Procedure for Coating Wrapping Rev 01
2/6
LARSEN & TOUBRO LIMITEDPAGE NO.- 2 OF 6
DATE:-05.01.2008
MSQ UP GRADATION (EPCC 1)PROJECT REV.NO.- 01
PROCEDURE FOR COATING ANDWRAPPING OF UNDERGROUND CARBON
STEEL PIPELINES.
PROCEDURE NO.-LT/MSQ/P/UG/CW/012
1.0 PURPOSE
1.1. This procedure describes guidelines to carry out tape coating of UG piping at IOCL PANIPAT
REFINERY MSQ UPGRADATION PROJECT.
1.2. In case of conflict between this procedure and contract specification, the latter shall govern.
2.0 REFRENCE DOCUMENTS:
2.1. As per Jacobs spec. No. 3177-LSS-109
2.2. AWWA C-203 Coal tar protective coating lining to steel carbon pipeline
2.3. SSPC-SP10 steel structure Painting council, surface preparation specification
2.4. ASTM G8 test method for cathodic disbanding of pipeline coating
3.0 MATERIALS:
3.1. Protective tapes and other materials brought to site shall be as per specification.
3.2. Manufacturers test certificates shall be submitted for review prior to use.
3.3. The primer shall be type B as specified in AWWA C-203.
3.4. Field and laboratory test shall be carried out for each batch of primer & tape.
3.5. Primer and tape shall be supplied by the same manufacturer.
4.0 PROCEDURE:
4.1. SURFACE PREPARATION:
4.1.1. Prior to blast cleaning, all oil, grease on the pipe surface shall be thoroughly removed
by flushing with suitable solvent as per SSPC SP-1 and wiping with clean tags.
Degreased pipe metal surface shall be shot/grit blast cleaned to SSPC-SP-10 or Sa 2 of
SIS-05-5900. This cleaning operation shall be followed immediately with priming by spraying /
brush.
APPROVED BY L & T REVIEWED / APPROVED BY JACOBS
7/30/2019 12 Procedure for Coating Wrapping Rev 01
3/6
LARSEN & TOUBRO LIMITEDPAGE NO.- 3 OF 6
DATE:-05.01.2008
MSQ UP GRADATION (EPCC 1)PROJECT REV.NO.- 01
PROCEDURE FOR COATING ANDWRAPPING OF UNDERGROUND CARBON
STEEL PIPELINES.
PROCEDURE NO.-LT/MSQ/P/UG/CW/012
4.1.2. Blast cleaned surface shall be adequately scrubbed manually with stiff wire brush
where ever blasted surface get rusted, prior to application of primer.
4.1.3. All weld joints shall be cleaned manually with stiff wire brush/buffing wheel after
assembly and welding, prior to priming.
4.2. PRIMING:
4.2.1. Immediately after girt blasting the surface shall be applied with fast drying unmodifiedpure chlorinated rubber based coal tar synthetic primer.
4.2.2. Second coat of primer to be applied before application of coal tar enamel. The entire
surface of pipe should be primed. No specific time gap between two coats of primer needs to
be maintained but after the second coat of primer, the enamel coating should before the
primer is completely hardened.
4.3. PREPARATION OF COATING MATERIAL:
The metal drums that shall be cropped or cut on suitable platform to prevent the enamelcoming in contact with wooden cinders, grass and other forms of contamination. The enamel
shall be confirmed to Type-I or Type-II coal tar enamel as per AWWA C-203. The cropped out
pieces if enamel may not Wight more then 10 kgs. The broken pieces shall be placed in a
clean melting kettle which is made of heavy duty, MS sheet in form of closed vessel. To
maintain uniform coverage of material required quantity of enamel is heated in the kettle with
temperature range of 2300C to 2400C. Temperature of enamel can be checked by dipping
thermometer in the enamel. Thermometer shall be used in heating kettle in a such way so as
read the temperature clearly. The thermometer shall have temperature range up to 3000
C.
APPROVED BY L & T REVIEWED / APPROVED BY JACOBS
7/30/2019 12 Procedure for Coating Wrapping Rev 01
4/6
LARSEN & TOUBRO LIMITEDPAGE NO.- 4 OF 6
DATE:-05.01.2008
MSQ UP GRADATION (EPCC 1)PROJECT REV.NO.- 01
PROCEDURE FOR COATING ANDWRAPPING OF UNDERGROUND CARBON
STEEL PIPELINES.
PROCEDURE NO.-LT/MSQ/P/UG/CW/012
4.4. MECHANICAL APPLICATION OF COATING AND WRAPPING :
4.4.1. The pipe shall be kept rotating on a machine having circumferential and linear motions,
while the pipes are in rotating condition, pour the hot cold enamel manually and spread
uniformly with the help of rubber brushes.
4.4.2. Simultaneously, one wrap of glass fibre tissue having properties as stated in Jacobs
specification shall be applied over the molten coal tar enamel. Initially, the wrap is held with
hand and pressed over the molten enamel. There after the revolving pipe puffs the fiber warpfrom the reel, which ensures continuous wrapping over the molten enamel with required
overlap (i.e. 13 mm).
4.4.3. Second coat of coal tar enamel as well as glass fiber tissue paper shall be applied as
per above procedure.
4.4.4. Third coat of molten coal tar enamel shall be applied next.
Final outer wrap of impregnated fibre felt shall be applied immediately over third coat of coal
tar enamel, similar to inner wrap application. The overlap at edges of all wrappings should be
minimum 13 mm. the coating shall be continuous for the full length of the pipe except 200 mmat both ends of the pipes.
Finally, carry out whit wash with Acrylic water emulsion Latex Paint Material. This application
will be carried out manually by paintbrushes. There after the pipes is lifted by suitable
methods and allowed to dry on wooden sleepers.
5.0 INSPECTION:
5.1. All stage inspection & documentation shall be carried out as per Format No. LT/MSQ/TC/020,
Rev.00
Profile gauge/comparator, for checking surface preparation as per SA 2 , shall be madeavailable.
5.2. After application of tape coating, visual inspection shall be carried out for uniformity without
any wrinkle, irregularities and overlapping width.
APPROVED BY L & T REVIEWED / APPROVED BY JACOBS
7/30/2019 12 Procedure for Coating Wrapping Rev 01
5/6
LARSEN & TOUBRO LIMITEDPAGE NO.- 5 OF 6
DATE:-05.01.2008
MSQ UP GRADATION (EPCC 1)PROJECT REV.NO.- 01
PROCEDURE FOR COATING ANDWRAPPING OF UNDERGROUND CARBON
STEEL PIPELINES.
PROCEDURE NO.-LT/MSQ/P/UG/CW/012
5.3. Thickness of the coal tar enamel coating shall be measured with the digital thickness gauge.
Minimal acceptable thickness shall be 4.5mm.
5.4. All coated and wrapped pipes shall be tested with the positive signalling device to indicate
any fault, holes, breaks or conductive particles in the protective coating. The test voltage shall
be 13 KV.
5.5. Peel test shall be conducted at temperature from 10C to 25C per AWWA-203 methods.
Acceptable criteria shall be as per AWWA-203.
6.0 REPAIR:
Wherever any holiday is observed or any defective work is found, remove the wrapping and
coating to the required extend from those areas by using a sharp knife. Then heated enamel
shall be applied manually over the area following the procedure described above and inner
and outer wrap applied. Holidays test shall repeated for the portion.
7.0MACHINE LIMITATION:
Machine used for coating and wrapping as described above can be used from pipes from
10 to 48 only. For pipes upto 8 and above 48 , coating and wrapping shall be done
manually with out rotation of pipes.
8.0 HANDLING OF COATED PIPES
The coated pipes shall be handled at all times with equipments such as wide belt slings and
padded skids designed to prevent damage to the coating. Bare cables, chains, hooks etc.
shall not be permitted to come in contact with coatings. A suitable crane may be used. Coatedpipes shall be supported at two bare ends clear from ground either on kids or sand bags.
APPROVED BY L & T REVIEWED / APPROVED BY JACOBS
7/30/2019 12 Procedure for Coating Wrapping Rev 01
6/6
LARSEN & TOUBRO LIMITEDPAGE NO.- 6 OF 6
DATE:-05.01.2008
MSQ UP GRADATION (EPCC 1)PROJECT REV.NO.- 01
PROCEDURE FOR COATING ANDWRAPPING OF UNDERGROUND CARBON
STEEL PIPELINES.
PROCEDURE NO.-LT/MSQ/P/UG/CW/012
9.0SAFETY PRECAUTIONS
9.1. Adequate and proper PPE shall be provided to persons involved in short of grit blasting work.
9.2. Adequate and proper PPE shall be provided to persons involved in hot application of coal tar
enamel along with the wraps.
9.3. Proper fire fighting system shall be provided during application of primer and enamel coatsand all safety requirements shall be ensured for under ground trenching, lowering & back
filling.
9.4 All precaution shall be observed as per the instruction of PMC/ OWNER.
APPROVED BY L & T REVIEWED / APPROVED BY JACOBS