Payne PG96VTA Installation, Start-Up, Operating And Service And Maintenance Instructions page 54

mm) per linear ft.(1-in (25 mm) per 4 ft.(1.2 M)) with no
sags between hangers is required. See Caution Box below.
CAUTION
!
FURNACE RELIABILITY HAZARD
Failure to follow this caution may result in nuisance short
cycling, frozen vent termination, and/or no heat.
Slope the vent and combustion air piping downward towards
furnace a minimum of 1/4- -in. (6 mm) per linear ft. of pipe.
19. Use appropriate methods to seal openings where combus-
tion air pipe and vent pipe pass through roof or sidewall.
Optional Installation of the Vent Pipe
NOTE: DO NOT USE
POLYPROPYLENE VENTING SYSTEMS.
This option provides a disconnect point for the vent pipe. The vent
pipe must be cemented to the plastic vent pipe adapter to maintain
a sealed vestibule. See Fig. 50.
1. Insert a length of vent pipe through the casing into the
outlet of the vent elbow.
2. Slide the plastic vent pipe adapter over the length of the
vent pipe down to the furnace casing. Mark the pipe where
it is flush with the outlet of the adapter.
3. Remove the pipe from the furnace and the adapter and cut
off any excess pipe.
4. Clean and prime the end of the pipe that is flush with the
vent adapter with a primer that is appropriate for the type of
pipe being used.
5. Re- -insert the pipe through the casing into the vent elbow.
6. Tighten the clamp around the outlet of the vent elbow.
Torque the clamp to 15 lb- -in.
7. Apply cement to the end of the pipe and to the inside of the
plastic vent adapter.
VENT PIPE FLUSH WITH ADAPTER
THIS TECHNIQUE FOR
VENT PIPE ADAPTER WITH GASKET
INSTALLED ON FURNACE VENT
PIPE IS CUT FLUSH WITH TOP OF
ADAPTER. PRIME AND CEMENT VENT
PIPE TO ADAPTER. ALLOW TO DRY
BEFORE INSTALLING VENT COUPLING.
Fig. 50 - - Optional Vent Pipe Flush with Adaptor
8. Slide the adapter over the vent pipe and align the screw
holes in the adapter with the dimples in the furnace casing.
9. Pilot drill 1/8- -in. screw holes for the adapter in the casing
and secure the adapter to the furnace with sheet metal
screws.
10. Loosen the clamps on the rubber vent coupling.
11. Slide the end of the coupling with notches in it over the
standoffs in the vent pipe adapter.
12. Tighten the clamp of the coupling over the vent pipe
adapter. Torque the lower clamp around the vent pipe
adapter to 15 lb- -in.
13. Pilot drill a 1/8- -in. hole in the combustion air pipe adapter.
14. Complete the vent and combustion air pipe as shown in
"Install the Vent and Combustion Air Pipe."
NOTICE
FOR POLYPROPYLENE VENTING SYSTEMS
When using polypropylene venting systems, all venting
materials used, including the vent terminations, must be from
the same manufacturer.
WARNING
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
DO NOT use cement to join polypropylene venting systems.
Follow the polypropylene venting system manufacturer's
instructions for installing polypropylene venting systems.
VENT PIPE FLUSH SHOWING COUPLING
54
ALIGN NOTCHES IN VENT PIPE
COUPLING OVER STAND-OFF
ON ADAPTER. TORQUE LOWER
CLAMP 15 LB-IN. WHEN REMAINING
VENT PIPE IS INSTALLED, TORQUE
UPPER CLAMP TO 15 LB-IN.
A13076