3.5.3.1
Epoxy Coating System
The epoxy coating system shall conform to the AWWA C213. Fittings, valves,
and joints shall be factory coated with materials identical to those used
on the pipe, or may be field-coated with a 2-part epoxy system recommended
by the manufacturer of the pipe coating system. Field protection may also
be provided for joints and fittings with a coal tar tape hot applied over a
compatible primer.
3.5.3.2
Bituminous Pipe Coating
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NOTE: If coating system similar to coal tar coating
and wrapping is required using different materials,
this paragraph shall be rewritten. Where
excessively corrosive soils are encountered, the
piping shall be given a second coating of coal-tar
enamel and a second wrapper of felt.
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Bituminous protective system shall be a coal-tar enamel and primer coating
system and shall consist of a coal-tar priming coat, a coal-tar enamel
coat, a wrapper of coal tar saturated felt, and a wrapper of kraft paper,
or a coat of water-resistant white-wash, applied in the order named and
conforming to the requirements of AWWA C203 in all respects as to
materials, methods of application, tests, and handling, except that an
interior lining shall not be applied. Joints and fittings shall be coated
and wrapped.
3.5.3.3
Polyethylene Pipe Coating
Continuous extruded polyethylene coating and adhesive undercoat application
procedure, including surface preparation, shall be a factory-applied system
conforming to NACE RP0185, Type A. Joints, valves, flanges, and other
irregular surfaces shall be tape-wrapped as outlined under the tape
wrapping system, except that the tape shall be applied half-lapped, and all
extruded polyethylene coating and adhesive undercoat surfaces to be
tape-wrapped shall be primed with a compatible primer before application of
tape. The primer shall be as recommended by the tape manufacturer and
approved by the applicator of the extruded polyethylene coating. Damaged
areas of extruded polyethylene coating shall be repaired by tape-wrapping
as described under the tape-wrapping system, except that any residual
material from the extruded polyethylene coating shall be pressed into the
break or shall be trimmed off. All areas to be taped shall be primed and
the tape shall be applied half-lapped.
3.5.3.4
Tape-Wrap Pipe Coating
Cleaned surfaces shall be primed before applying tape as recommended by the
manufacturer of the tape. The tape shall be an approved,
pressure-sensitive, organic plastic tape with a minimum nominal thickness
of 0.51 mm 0.020 inch. The tape shall conform to ASTM G 21 for fungus
resistance. Tape shall be applied to clean, dry, grease-free, and
dust-free surfaces only. Weld beads shall be wire-brushed. All burrs and
weld spatter shall be removed. Weld beads shall be covered with one wrap
of tape before spiral wrapping. At each end of straight runs, a double
wrap of one full width of tape shall be applied at right angles to the axis
of the spiral wrapping. Kraft paper protective wrapping, if any, shall be
removed from the pipe before the tape is applied. Material which is
SECTION 15555A
Page 92
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