and other accessories, one layer half-lapped and stretched sufficiently to
conform to the surface shall be applied, followed by a second layer
half-lapped and applied with tension as it comes off the roll.
3.5.3.4
Epoxy Coating System
The epoxy coating system shall conform to AWWA C213, Type II. Fittings,
valves, and joints shall be factory coated with materials identical to
those used on the pipe, or may be field coated with a two-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.
3.5.3.5
Coating Inspection and Testing
After field coating of the pipe joints, the entire pipe shall be inspected
with an electric holiday detector having an operating crest voltage of from
12,000 to 15,000 volts when using a full-ring, spring-type coil electrode.
The holiday detector shall be equipped with a bell, buzzer, or other
audible signal which operates when a holiday is detected. All detected
holidays in the protective covering shall be repaired. Occasional checks
of holiday detector potential will be made by the Contracting Officer to
determine suitability of the detector. The inspection for holidays shall
be performed just before covering the pipe with backfill and every
precaution shall be taken during backfill to prevent damage to the
protective covering. Equipment and labor necessary for inspection shall be
furnished by the Contractor.
3.5.4
Installing Buried Piping
Pipe and accessories shall be handled carefully to assure a sound,
undamaged condition. Care shall be taken not to damage coating when
lowering pipe into a trench and when backfilling. Nonmetallic pipe shall
be installed in accordance with pipe manufacturer's instructions.
Underground pipelines shall be laid with a minimum pitch of 25 mm per 15 m
1 inch per 50 feet. Horizontal sections shall have a minimum coverage of
450 mm 18 inches. Piping shall be free of traps and shall drain toward
tank. The full length of each section of underground pipe shall rest
solidly on the pipe bed. Piping connections to equipment shall be as
indicated, or as required, by the equipment manufacturer. Tank connections
shall be made with two elbow swing joints [or flexible connectors] to allow
for differential settlement. The interior of the pipe shall be thoroughly
cleaned of all foreign matter before being lowered into the trench and
shall be kept clean during installation. The pipe shall not be laid in
water or when the trench or weather conditions are unsuitable. When work
is not in progress, open ends of pipe and fittings shall be securely closed
so that water, earth, or other substances cannot enter the pipe or
fittings. Any pipe, fittings, or appurtenances found defective after
installation shall be replaced. Threaded joints shall be made with tapered
threads and shall be made perfectly tight with joint compound applied to
the male threads only. This requirement shall not apply for the gauging
hatch or similar connections directly over the tank where the line
terminates in a fitting within a cast-iron manhole designed to allow for
differential setting. Where steel piping is to be anchored, the pipe shall
be welded to the structural steel member of the anchor and the abraded area
shall be patched with protective coating or covering as specified. Piping
passing through concrete or masonry construction shall be fitted with
sleeves. Each sleeve shall be of sufficient length to pass through the
entire thickness of the associated structural member and shall be large
SECTION 15559A
Page 105
Previous Page
