3.1.6
Connections to Metal Pipe
Use flanged connections between FRP pipe and metal pipe with the metal pipe
anchored within 1.50 meters 5 feet of the connection. Do not transmit
expansion and load forces of metal piping to the FRP pipe. Do not bury
metal-to-FRP connections. Install washers under bolt heads and nuts on
flanges, and torque bolts in accordance with manufacturer's requirements.
3.1.7
Air Vents and Low Point Drains
Install hand operated air vent valves at all high points in the piping.
Install hand operated low point drain valves at low points in the piping.
3.1.8
Pitch
Pitch horizontal buried fuel piping, unless otherwise indicated, with a
downward grade of not less than 25 mm in 15 meters one inch in 50 feet in
the direction of low point drains.
3.2
FRP PIPE INSTALLATION
3.2.1
FRP Pipe Assembly
Visually inspect the inside of each length of pipe to ensure that it is
clear and clean prior to installation. Not more than 12 meters 40 foot
lengths of FRP pipe can be assembled over or beside the trench. Assemble
greater lengths in the trench. Assemble outside the trench on timbers with
the pipe blocked to hold alignment. Lower pipe into the trench in
accordance with the manufacturer's recommendations. Lowering operation
shall not move or disturb FRP pipe where joints are being assembled and
cured. Block and support FRP pipe assembled in the trench with bedding to
hold alignment.
3.2.2
Thrust Blocks
Cast thrust blocks after successful completion of hydrostatic testing.
Encase each elbow, tee, and change in size or direction of the FRP pipe in
a concrete thrust block with dimensions sized to handle thrusts from design
temperatures and pressures in accordance with FRP pipe manufacturer's
recommendations and local soil conditions. In any case, thrust block shall
provide a minimum of 0.30 square meter 3 square feet of thrust bearing
surface against undisturbed soil, able to withstand both tensile and
compressive loads, and with a minimum pipe-to-bearing surface single
dimension of 255 mm 10 inches, and 0.255 cubic meter 9 cubic foot minimum
volume. Provide in-line thrust or anchor blocks as indicated on straight
runs and outside of manholes and wall penetrations. Size in accordance with
FRP pipe manufacturer's recommendations to handle thrusts from design
temperatures and pressures. In any case, provide 0.42 square meter 4.5
square foot minimum bearing surface in each FRP pipe direction cast against
undisturbed soil, 0.37 cubic meter 13 cubic foot minimum volume. Concrete
shall conform to [Section 03300N CAST-IN-PLACE CONCRETE] [ASTM C 94, [25]
[30] MPa [3000] [4000] psi].
3.2.3
Bending of Fiberglass Reinforced Plastic Pipe
Limit bending of pipe to follow ditch contours to long trench curvatures
and do not permit abrupt changes in pipeline direction. Bending radii
shall not be less than shown in the manufacturer's installation
instructions. Do not make bends until all joints in the section of pipe to
SECTION 15191N
Page 9
Previous Page
