Thermal Solutions APEX APX425C Installation, Operating And Service Instructions page 23

4
Venting
(continued)
b. Design the vent system to allow 3/8 in.
(9.5 mm) of thermal expansion per 10 ft.
(3.0 m) of CPVC/PVC pipe. Runs of 20 ft.
(6.1 m) or longer that are restrained at both
ends must use an offset or expansion loop.
Refer to Figure 4-18 and Table 4-17.
c. All CPVC/PVC vent and combustion air pipe
joints must be cleaned with primer and
glued with cement. Follow all manufacturer
instructions and warnings when preparing
pipe ends for joining and using the primer
and the cement.
5. Horizontal Sidewall Termination
a. Standard Two-Pipe Termination
See Figure 4-6.
106308-05 - 3/23
Figure 4-15: Field Installation CPVC/PP/SS Vent Connector
Figure 4-16: Near-Boiler Vent/Combustion Air Piping
APEX Installation, Operating, & Service Instructions
i. Vent Piping
Running PVC vent pipe inside
Enclosures and through Walls:
• PVC vent pipe must be installed in
such way as to permit adequate
air circulation around the outside
of the pipe to prevent internal wall
temperature rising above ANSI
Z21.13 standard specified limit.
• Do not enclose PVC venting. Use
higher temperature rated CPVC pipe
in enclosed spaces or to penetrate
combustible or non-combustible
walls.
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