mechanical vents

[Jerome W. Young]

Jerry,
Is this the vent you referred to as not proper for a single family home. I believe you stated it was for mobile home use? I found another one today at an island sink.

[Jerry Peck]

.Yes.

[Gunnar Alquist]

So... you removed it? Cool.

That is indeed the offending device. Wish I could think of a better name than "mechanical vent".

[Jerome W. Young]

owner couldnt get under to see what i was talking about, so i offered to show him the device. this one came right off.:)

[Robert Dalga]

It's called an 'air addmittance valve' and they are commonly used in kitchen islands (since you can't run a vent stack up). They are acceptable (in new construction) up here in SW lower MI and I suppose if they fail they would be easy to replace. P.S. Yes, you will find them in mobile homes alot.

[Jerry Peck]

It's called an 'air addmittance valve' and they are commonly used in kitchen islands (since you can't run a vent stack up). They are acceptable (in new construction) up here in SW lower MI and I suppose if they fail they would be easy to replace. P.S. Yes, you will find them in mobile homes alot.

Robert,

You are mixing two things up:
1) Air admittance valves
2) Mechanical vents

The white ones (by Studor and Oatey) are air admittance valves. The black ones on mechanical vents and are only approved for use in mobile homes.

See that spring in the first photo Jerome posted? That makes it a mechanical vent, which is not allowed in regular homes.

Jerome, yes, they should be able to be removed, and they should also have pipe thread tape around the threads to seal it in place when screwed in.

[Scott Faris]

Jerry is right. What you have is a mechanical vent sometimes called a "cheater vent". They are allowed in manufactured homes and rated only for 1-2 Drainage Fixture Units (so really just for a sink). They are not allowed on any stick built construction. Air Admittance Valves Ayrlett, Oatey, and Studor are allowed in various states according to their codes.

Scott