Pipelaying Tender-VOL IV - WorleyParsons.com

REWARI KANPUR PIPELINE
PROJECT
3 LAYER POLYETHYLENE COATING OF
LINEPIPES
DOCUMENT NUMBER
0068-00-SPC-2004
Revision 0
Specified Pipe OD, Inches (mm)
Minimum Coating Thickness In mm
Total
[1] [2] [2, 3]
FBE Adhesive PE Normal
Reinforced
Type (n)
Type (v)
Up to 4½ (114.3) 0.15 0.2 1.45 1.8 2.5
Over 4½ (114.3) Up to 10¾
(273.1)
0.15 0.2 1.65 2.0 2.7
Over 10¾ (273.1) to below 20
(508.0)
From 20 (508.0) to below 32
(813.0)
0.15 0.2 1.85 2.2 2.9
0.15 0.2 2.15 2.5 3.2
From 32 (813.0) and above 0.15 0.2 2.65 3.0 3.7
Notes:
1. Epoxy shall be applied by electrostatic spray method the maximum thickness shall not
exceed the epoxy thickness specified by epoxy powder manufacturer.
2. Grafted co-polymer adhesive and polyethylene layers shall be applied by extrusion.
3. In case HDPE is used as top coat, 10% reduction in PE top coat thickness is permissible
4. Unless indicated otherwise in Purchase Order, total thickness corresponding to Normal
Type (n) coating shall be applicable.
EPOXY APPLICATION
Epoxy powder shall be sprayed on to heated pipe using electrostatic spray technique.
Only dry air, free of oil and moisture shall be used in the coating chamber and epoxy
spraying system. Dew point of air supplied to epoxy spray/recycling system shall be at least
- 40°C.
Air pressure in the epoxy spray guns shall be controlled, continuously monitored and
recorded at least four times per working shift (maximum 12 hours). The air pressure shall be
controlled within the limits established during coating application procedure qualification.
The monitoring system shall be able capable of raising an alarm / activate audio
system (hooter) in the event of change in air pressure beyond the set limits. All pipes
coated during the duration of air pressure deviation beyond set limits shall be stripped and
recoated. The recycled epoxy powder mixing with fresh epoxy powder shall be permitted
subject to following conditions:
Quality of recycled epoxy powder has been established to be acceptable during
coating application procedure qualification.
Proportion of the recycled epoxy powder in the working mix does not exceed that
established during coating application procedure qualification or 20% at a time,
whichever is less.
Quality of the recycled powder is checked minimum once per working shift (maximum
12 hours) by visual examination, thermal analysis & moisture content testing and
properties of recycled epoxy are established to be within manufacturer specified
range.
0068-FMT-01 Page 17 of 31
Copyright L&T-GULF Private Limited. All rights reserved.
[3, 4]