Navien NFC-175 Installation & Operation Manual page 76

9.3.2 Connecting the Pipe to the Damper
1. Measure 1- / " from the end of the vent pipe, then draw a mark
1
2
at that distance.
2. Insert the vent pipe into the vent collar to start the vent run.
Make sure to completely slide the vent into the collar until the
end makes contact with the bottom of the socket.
Verify that 1-
Note
inserted into the collar and that the mark is no longer
visible.
3. Tighten the clamp with a screwdriver to properly seal the joint.
CAUTION
Do not start the vent run with a 90° street elbow at the vent
collar. Using a street elbow directly at the collar will not allow
for a tight seal between the appliance and vent pipe. A length
of straight pipe must be used when starting the vent run.
76 Installing a Common Vent System
Mark 1-1/2" from
the end of the pipe
1-1/2"
/ " of the pipe has been completely
1
2
The length of vent pipe from the unit to the common
Note
vent main trunk pipe must not exceed 20' of
equivalent length.
9.3.3 Assembling the T Joint
1. Use the proper reducers to connect the 2" branch pipe from
the unit to the common vent tee joint. Apply the proper
solvent cement to the mating surfaces.
Apply
Cement
Multiple reducers can be used to allow proper
Note
connection of 2" vent pipe to the common vent
system.
2. Assemble the tee joint assembly to the vent pipe. Apply
solvent cement to the mating surfaces.
Apply
Cement
PVC Reducer