regulator.
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An aboveground locked, valved and capped emergency gas supply connection
shall be provided [downstream] [upstream] of the pressure regulator. The
connection shall be located outside of the building within 300 mm (12
inches) 12 inches of the exterior wall and installed in a weatherproof box
which is mounted on the exterior wall and clearly marked with an
appropriate metal sign mounted on wall above.
3.4
WORKMANSHIP AND DEFECTS
Pipe, tubing, and fittings shall be clear and free of cutting burrs and
defects in structure or threading and shall be thoroughly brushed and blown
free of chips and scale. Defective pipe, tubing, or fittings shall be
replaced and shall not be repaired.
3.5
PROTECTIVE COVERING
3.5.1
Protective Covering for Underground Steel Pipe
Except as otherwise specified, protective coverings shall be applied
mechanically in a factory or field plant especially equipped for the
purpose. Valves and fittings that cannot be coated and wrapped
mechanically shall have the protective covering applied by hand, preferably
at the plant that applies the covering to the pipe. Joints shall be coated
and wrapped by hand. Hand coating and wrapping shall be done in a manner
and with materials that will produce a covering equal in thickness to that
of the covering applied mechanically.
3.5.1.1
Thermoplastic Resin Coating System
The coating system shall conform to NACE RP0185, Type A. The exterior of
the pipe shall be cleaned to a commercial grade blast cleaning finish in
accordance with SSPC SP 6. Adhesive compound shall be applied to the pipe.
Immediately after the adhesive is applied, a seamless tube of polyethylene
shall be extruded over the adhesive to produce a bonded seamless coating.
The nominal thickness of the pipe coating system shall be 0.25 mm (10 mils)
10 mils (plus or minus 10 percent) of adhesive and 1.0 mm (40 mils) 40 mils
(plus or minus 10 percent) of polyethylene for pipes up to 400 mm (16
inches) 16 inches in diameter. For pipes 450 mm (18 inches) 18 inches and
larger in diameter, the pipe coating system thickness shall be 0.25 mm (10
mils) 10 mils (plus or minus 10 percent) adhesive and 1.5 mm (60 mils)60
mils (plus or minus 10 percent) polyethylene. Joint coating and field
repair material shall be applied as recommended by the coating manufacturer
and shall be one of the following:
a.
Heat shrinkable polyethylene sleeves.
b.
Polyvinyl chloride pressure-sensitive adhesive tape.
c.
High density polyethylene/bituminous rubber compound tape.
The coating system shall be inspected for holes, voids, cracks, and other
damage during installation.
3.5.1.2
Inspection of Pipe Coatings
Any damage to the protective covering during transit and handling shall be
SECTION 02556A
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