10.
11.
12.
Do not subject pipe to strains that will overstress or buckle piping or
impose excessive stress on joints.
Branch saddle fusions shall be joined in accordance with manufacturer’s
recommendations and procedures. Branch saddle fusion equipment shall
be of a size to facilitate saddle fusion within the trench.
Before butt fusing pipe, inspect each length for presence of dirt, sand,
mud, shavings, and other debris or animals. Remove debris from pipe.
Cover open ends of fused pipe at end of each working day. Cap to
prevent entry by animals or debris.
Use compatible fusion techniques when PEs of different melt indexes are
fused together. Refer to manufacturer's specifications for compatible
fusion.
Fusion welding shall not be performed when pipe ends are exposed to
precipitation. CONTRACTOR shall provide temporary welding shelter if
necessary.
All HDPE cuttings from pipe facing and drilling shall be removed from the
pipe network by CONTRACTOR prior to turning the Project over to
OWNER. CONTRACTOR shall clean the entire pipe network associated
with the Project if HDPE cuttings are encountered in the pipe network by
OWNER following completion of the project.
All interior butt-fusion weld beads shall be removed from the pipe
i.e. all HDPE pipe must de-beaded) in accordance with the
manufacturer’s recommendations.
C. Flange Jointing
1.
2.
Use on flanged pipe connection sections.
Convoluted stainless steel backup rings shall be used for joining HDPE
pipes below grade, and epoxy-coated carbon steel backup flanges shall be
used above grade.
Butt fuse fabricated flange adapters to pipe.
Observe the following precautions in connection of flange joints.
a. Use full-face Viton gaskets only.
b. All fasteners shall be Type 304 stainless steel below grade, and zinc-
plated steel above grade. Do not use hot-dipped galvanized
fasteners.
b. Align flanges or flange/valve connections to provide tight seal.
Require nitrile-butadiene gaskets if needed to achieve seal. Gaskets
are required for flange/valve connections. Flange adapters may
require modification or special adapters when used against butterfly
valves to provide clearance for disc to open fully.
c. U.S. Standard round washers as may be required on some flanges in
accordance with manufacturer’s recommendations. Bolts shall be
lubricated in accordance with manufacturer’s recommendations.
File No. 3066.09
High-Density Polyethylene Pipe 15210 - 8 of 15 Revised February 2019
