AHRI APEX, Installation, Operating And Service Instructions

Page: 28 / 124

28
IV. Venting
C. Polypropylene Venting (continued)
b. Follow all manufacturer instructions and
warnings when preparing pipe ends for joining
and when assembling the vent/combustion air
system.
c. Use locking band clamps at all vent pipe joints.
NOTICE
The venting system must be free to expand
and contract and supported in accordance
with installation instructions included by the
original polypropylene venting component
manufacturers, M&G/DuraVent or Centrotherm,
whichever applicable. Polypropylene pipe
sections must be disengaged 1/4 to 5/8 in.
(6 mm to 16 mm) per joint to allow for thermal
expansion.
4. Running Flexible Polypropylene Vent
(Liner) Through Unused Chimney Chase
WARNING
Asphyxiation Hazard. Flexible polypropylene
vent must be installed only in an UNUSED
chimney. A chimney, either single or multiple
flue type, is considered UNUSED when none
of the flues is being used for any appliance
venting. Where one of the multiple flues is
being used for an appliance venting, the flexible
vent installation is not permitted through any of
adjacent flues.
NOTICE
Pressure drop for flexible polypropylene liner
is 20% greater than from rigid pipe. Multiply
measured flexible polypropylene liner length by
1.2 to obtain equivalent length.
Maximum equivalent length of flexible
polypropylene liner is 48 ft. (14.6 m).
Figure 14: Vent System Field Modification to Install
PVC to PP Adapter (M&G/DuraVent Shown)
a. Models APX425 and APX525 are listed for
vertical venting by installing flexible vent in an
UNUSED masonry chimney/chase and supplying
combustion air through a separate wall or roof
combustion air terminal.
b. Refer to Figure 15 for details of chimney chase
installation.
c. Flexible polypropylene pipe must be treated
carefully and stored at temperatures higher than
41°F (5°C).
d. Do not bend or attempt to install flexible pipe if
it has been stored at lower ambient temperature
without allowing the pipe to warm up to a higher
temperature first.
WARNING
Asphyxiation Hazard. Bending or attempting
to install flexible pipe if it has been stored at
ambient temperature below 41°F (5°C) will
cause material to become brittle and lead to
cracks, resulting in flue gas leaks.
Do not install flexible polypropylene pipe
at an angle greater than 45 degrees from
vertical plane when used for combustion
product venting. Failure to do so will result
in improper condensate drainage towards
the boiler and possible subsequent vent
pipe blockage.
e. When flexible polypropylene pipe (liner) is used
for combustion product venting, it must not be
installed at an angle greater than 45 degrees from
vertical plane. This will insure proper condensate
flow back towards the boiler.
f. When flexible polypropylene pipe (liner) is used
for combustion air supply to a boiler, the pipe
(liner) can be installed in vertical or horizontal
position.
g. Follow flexible polypropylene pipe (liner)
manufacturer specific installation instructions
regarding application/listing, permits, minimum
clearances to combustibles, installation details
(proper joint assembly, pipe support and routing,
gasket and fitting installation, optional tooling
availability/usage, routing through masonry
chimney for combustion product venting or,
combination of combustion product venting and
combustion air supply).
h. When there is a conflict between flexible
polypropylene pipe (liner) manufacturer
installation instructions and Apex boiler
Installation, Operating and Service Instructions,
the more restrictive instructions shall govern.