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 Allowable number of bends in a DWV vent pipe?
Author: Dan0 (TN)

I realize bends add resistance and the fewer better,
but is there a maximum number of bends allowed?

I seem to remember (4) 90s...
Not sure where I got that from.
(and of course, 45° bends are preferred)


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 Re: Allowable number of bends in a DWV vent pipe?
Author: exapprentice30 (MA)

You can use 90s on a vent when your 6 inches above the flood rim level of the fixture your venting. In some states you have to use drainage fittings to connect the vent to the drain and vent fitting must be rolled up at a minimum of 45 degrees where the vent connects to the horizontal drain and you cant offset below the flood rim level using 90s too. You can use a vent elbow for a vent which is the tightest bend you can get.

Edited 3 times.

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 Re: Allowable number of bends in a DWV vent pipe?
Author: packy (MA)

i've seen a restriction on the number of 90's you can use on a gas fan forced vent but never heard of a DWV venting restriction.

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 Re: Allowable number of bends in a DWV vent pipe? clap
Author: Dan0 (TN)

Thanks for the replies!
I appreciate the help!

Edited 1 times.

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