Weil-McLain 155 Boiler User Manual


 
Part number 550-101-235/0903
12
GAS-FIRED WATER BOILER — Vent Supplement
Installing vent & air piping
(continued)
5
Figure 10 Piping to through-roof terminations
Figure 9 Piping to sidewall terminations
Table 2 Min/max lengths of either air piping
or vent piping
When a large number of elbows is
needed with 3-inch piping, use long
radius elbows to reduce pressure drop.
This allows a longer run of piping. See
Table 2 notes for details.
Do not insulate vent piping. Exception: Where vent pipes pass through unheated spaces, such as
crawl spaces or unheated garages, apply ½ inch fiberglass insulation to the portion of the vent pipe
in the unheated space only.