Volume-II of IV - GAIL

• Damages caused to coating by handling such as scratches, cuts, dents,
gouges, not picked up during holiday test, having a total reduced
thickness on damaged portion not less than 2.0mm and an area not
exceeding 20 cm 2 shall be rebuild by heat shrink patch only and without
exposing to bare metal.
• Defects or size exceeding above mentioned area or holidays of width less
than 300 mm shall be repaired with heat shrinks repair patch by exposing
the bare metal surface.
• Defects exceeding the above and in number not exceeding 2 per pipe and
linear length not exceeding 500mm shall be repaired using heat
shrinkable sleeves of HTLP80 or equivalent.
• Pipes with bigger damage shall be stripped and recoated.
• In case of coating defect close to coating cut back, CONTRACTOR shall
remove the coating throughout the entire circumference of the pipe down
to the steel surface and increase the coating cut back length. Now if the
coating cut back exceeds 140mm of linear length of pipe then the coating
shall be repaired by the use of heat shrinkable sleeves thereby making up
the coating cut back length of 120mm.
Not withstanding the above, under no circumstances, if the defects exceeds
70mm from the original coating cut back length, the entire coating shall be
removed and the pipe shall be recycled through the entire coating procedure.
Irrespective of type of repair, the maximum nos of repair of coating shall be as
follows :
• Holiday repair of size ≤ 100 cm 2 attributable to process of coating
application shall be maximum of one per pipe.
• In addition to the above, defects to be repaired by heat shrink patch/
sleeve shall be maximum 2(two) per pipe.
Defects exceeding the above limits shall cause pipe coating rejection, stripping
and recoating. The above is exclusive of the repairs warranted due to testing as
per this specification.
All repairs carried out to coating for whatever reason shall be to the account of
CONTRACTOR.
Cosmetic damages occurring only in the Polyethylene layer only need not be
repaired by exposing upto steel surface, as deemed fit by the COMPANY
representative. In any case the CONTRACTOR shall establish his material,
methods and procedure of repair that results in acceptable quality of product by
testing and shall receive approval from COMPANY prior to use.
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