24
Figure 19: Vertical Concentric Vent installation
outer pipes to start the screw. Use a drill stop or
other means to ensure that the drill bit does not
penetrate more than 3/8” into the outer pipe. Do
not use sheet metal screws longer than ½”.
When Additional Concentric Vent Piping isneeded
1. If additional concentric vent piping is needed:
a. Concentric Vent Cut-To-Length Extension pipes,
identied in Tables 8 and 10 CAN BE CUT
to required length when used as an extension.
These pipes have plain male end and beaded
female end. Always cut the pipe from plain
male end. See Figure 20 ‘Cut-To-Length
Extension (Cuttable)”.
b. The remaining Concentric Vent Fixed Extensions
shown in Table 8 CANNOT BE CUT. These
pipes have beaded male and beaded female ends.
See Figure 21 ‘Fixed Extension (Non-Cuttable)’.
2. To cut the Concentric Vent Straight pipe to required
length refer to Figure 22 “Cutting Straight Pipe” and
follow the procedure below:
a. Determine the required length of the outer pipe.
When doing this allow an additional 1” of length
for insertion into the female end of the adjoining
pipe. Mark the cut line on the outer pipe.
Figure 21: Fixed Extension (non-Cuttable)
Figure 20: Cut-To-Length Extension (Cuttable)
b. Remove the plastic inner pipe by pulling it out
from the female end.
c. Cut the OUTER PIPE ONLY at the point
marked in Step (a) using aviation shears, a
hacksaw, or an abrasive wheel cutter. Be careful
to cut the pipe square. Deburr the cut end with a
le or emery cloth.
d. Make an insertion mark 1” from the male end of
the outer pipe.
e. Cut the plastic inner pipe so that it will protrude
3/8” beyond the male end of the outer pipe when
reinstalled in the outer pipe. Use a ne tooth
hacksaw or a PvC saw to cut the plastic pipe and
be careful to cut the pipe square. Deburr the cut
edge of the plastic pipe with a le, razor blade or
ne sandpaper.
f. Reinstall the inner pipe.
3. To join Concentric Vent Pipe refer to Figure 23
“Joining Cuttable Pipe” and Figure 24 “Joining
Non-Cuttable Pipe” and follow the procedure below:
a. Start assembly of the vent system at the boiler.
Lubricate the brown gasket in the boiler vent
collar with a few drops of water.