Bathtub trap/ vent/ double sanitary tee config - allowable?

[BobsDIY]

Hi all

I've attached a picture of what I would like to do.
Is this allowable?

Thanks
Bob

 

[Reach4]

No. You need to move the vent away from the trap a bit. I am thinking a minimum of 2 pipe diameters. I don't know what fitting you use for that.

 

[Sponsor]

 

[BobsDIY]

No. You need to move the vent away from the trap a bit. I am thinking a minimum of 2 pipe diameters. I don't know what fitting you use for that.

Thanks Reach4.

I know the length of a trap-arm has to be that minimum distance but every time I see that distance, it is from the weir to a vertical stack/vent. I believe the distance is to prevent water going down the stack from sucking the water out of the trap. In this configuration, the vent is right above the trap and I can't envision any vacuum forming anywhere.

This will be inspected by the county so it will fail if it is no good but I was wondering if anyone has seen this configuration in use anywhere? I have a tight situation which is why I am exploring this option.

 

[hj]

You are creating a "crown vent" and they have been outlawed since at least the 40's. It is NOT suction that is the problem with it. The problem is "stuff" going through the trap and "jumping" up into the vent to build up and eventually clog it.

 

[BobsDIY]

Okay, that makes a lot of sense. Thanks

Bob