Pipelaying Tender-VOL IV - WorleyParsons.com

REWARI KANPUR PIPELINE
PROJECT
3 LAYER POLYETHYLENE COATING OF
LINEPIPES
DOCUMENT NUMBER
0068-00-SPC-2004
Revision 0
5.5 VIS UAL INS P ECTION
Pipes shall be visually inspected throughout the coating process from incoming bare
pipe to finished coated pipes as described herein below:
5.5.1. INSPECTION OF INCOMING PIPES
All incoming pipes, before any coating application process starts, shall be examined
visually for any surface defects such as split seams, dents, gouges, slivers or other
imperfections that would make the pipe unsuitable for use. Pipes with such defects shall
be repaired in accordance with approved procedure before they are released for further
processing.
5.5.2. INSPECTION OF BLAST CLEANED PIPES
Surface of pipes after blast cleaning shall be examined for any defects injurious to coating
application.
Surface profile shall be examined by using suitable instrument such as surface profile depth
gauge for compliance to anchor pattern requirements. In addition the pipe surface shall be
checked for the degree of cleanliness (Sa 2½), degree of dust and shape of profile.
In addition, inside surface of the pipe shall also be visually examined for presence of any
foreign material or shots and grit (free or embedded/sticking to pipe inside surface). Any
foreign material or shots/grit present in the pipe shall be completely removed by suitable
means (mechanical brush, high pressure air jets, by tilting of pipe etc.).
The blast-cleaned surface shall not be contaminated with dirt, dust, metal particles, oil, water
or any other foreign material, nor shall the surface or its anchor pattern be scarred or
burnished.
5.5.3. INSPECTION OF COATED PIPES
Each coated pipe shall be visually checked for imperfections and irregularities of the coating.
The resultant coating shall have a uniform appearance with natural colour & gloss and shall
be free from air bubbles, blisters, wrinkles, scratches, engravings, cuts, swellings,
disbonded zones, tears, voids, irregularities, discontinuities and separation between
layers of FBE/adhesive/PE. Special attention shall be paid to the areas adjacent to the
weld seam (if applicable). Coating surface shall not be physically damaged or contaminated
with any foreign material such as dirt, metal particles, coating debris during application,
curing, and handling process.
5.6 SOLUBLE SALT MEASUREMENTS
Chlorides and ferrous salts present on pipe surface that can affect the coating
performance shall be monitored prior to application of coating.
After blast cleaning, all pipes shall be tested for salt contamination. One test shall be
carried out at each end of each pipe using salt meter (SCM 400 or approved equivalent).
The acceptance criteria shall be 2 µg/cm 2 . Any pipe having salt contamination
exceeding 2 µg/cm 2 shall be treated by phosphoric acid wash followed by deionized
water wash in accordance with the recommendations of the manufacturer.
The Contractor shall submit a detailed procedure for phosphoric acid wash for Company
approval.
0068-FMT-01 Page 25 of 31
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