Questions on assembling b-vent pipe

darsunt

I've noticed that the b-vent pipes are designed to snap together tightly. Do you still need to fasten them together with sheet metal screws?

Also are b-vent products from different manufacturers compatible? The local HD has American Metal Products, but they do not have some of the lengths I need and I may have to go looking at other stores. If, say the local lumberyard has b-vent piping from a different vendor, could I still use it with American Metal Products pipe?

coolmen

you must use the same brand. your not suppose to screw into b vent pipeing however the duravent pipes sometimes are very diffacult to turn to lock so i would use screws at the connection. the other type of b vent witch locks in place when pushed together and with a locking ring i dont screw in place. when secureing the bvent with metel hangers or straps I will screw to secure. I feel that if he chimney was not secured and falls or breaks at the seam some one could seriously get hurt.

geo fan

It is against code to screw into b-vent this goes double for all-fuel (oil) the reason is if the wall is penatrated it will transfer heat out and is a potential fire hazard .If secured with the proper hangers in the proper intervals you dont have a thing to worry about

darsunt

The present vent system expands from 3" pipe to 4" pipe. Is this necessary?
By the way, it is from a water heater.