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 coating 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. Piping installed in valve boxes or
manholes shall also receive the specified protective coating.
3.4.5.1
Regular Surfaces, Fittings, and Couplings
Tape shall be initially stretched sufficiently to conform to the surface to
which it is applied, using one layer lapped at least 25 mm. 1 inch. Tape
shall overlap the extruded polyethylene coated piping 75 mm 3 inches at all
joints. A second layer, lapped at least 25 mm, 1 inch, with a tension as
it comes off the roll shall be applied and pressed to conform to the shape
of the component.
3.4.5.2
Damaged Areas of Extruded Polyethylene Coating
Residual material from coating shall be pressed into the break or trimmed
off. Tape shall be applied spirally and one-half lapped as it is applied.
Tape shall extend 75 mm 3 inches beyond the damaged area. A double wrap of
one full width of tape shall be applied at right angles to the pipe axis to
seal each end of the spiral wrapping.
3.4.5.3
Existing Piping Affected by the Contractor's Operation
Pipe shall be wrapped to 75 mm 3 inches beyond the point of connection.
3.5
CATHODIC PROTECTION
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NOTE: The need for cathodic protection should be
evaluated on an individual project basis.
**************************************************************************
Install cathodic protection systems for buried metallic piping systems.
Final adjustments for impressed current systems shall be accomplished by a
certified National Association of Corrosion Engineer (NACE).
3.6
BURIED UTILITY WARNING
Warning tape shall read "CAUTION BURIED FUEL PIPING BELOW" or similar
wording. Bury tape with the printed side up at a depth of 300 mm 12 inches
below the top surface of earth or the top surface of the subgrade under
pavements.
3.7
CONCRETE MANHOLES
Install under this section as specified in Section 03300N CAST-IN-PLACE
CONCRETE. Concrete shall have a minimum strength of 30 MPa 4000 psi, air
entrained admixture 133 gram per cubic meter 3.6 ounces per cubic yard,
with water-reducing admixture 814 gram per cubic meter 22 ounces per cubic
yard, reinforced with deformed steel bars. Construct manhole bottom and
sides by one monolithic pour with concrete sections a minimum 200 mm 8
inches thick an extending a minimum 150 mm 6 inches above grade. Manhole
bottom shall have 356 mm 14 inch round or square sump by 305 mm one foot
deep. Cast-iron steps with nonslip surfaces, spaced 300 to 406 mm 12 to 16
SECTION 15194N
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