Trap Location

[jpm6621]

I got a trap that is in the way in the basement as far as head room. Its from the tub with the tailpipe going through the floor directly into the trap in the basement. I can't raise it any higher. Can i put this trap down farther on the horizontal drain leading to the stack with a street elbow on one end of the trap connecting to the horizontal pipe.

 

[Beni]

What your looking at is a running trap. Depending on where you live you might be able to do that legally. The issue is that running traps tend to siphon under high loads which is a big NO NO.

Personally, I believe that for a tub, a running trap would be fine. This as the water at the end of a tub drain cycle, runs slower, making the siphoning of the trap highly unlikely. You would need to talk with your inspector or code official to be sure

 

[jpm6621]

Will an Air Admittance Valve help/prevent siphoning from ghis trap you talk about. I have one in place right now. This ends up draining into the main stack below where the toilet enters so i was advised to use the AAV to avoid the trap from being siphoned from the toilet.

 

[Beni]

An AAV would prevent the trap from siphoning. as would up sizing the drain line down stream of the trap one size.

Nowadays with 1.6 gallon flush toilets, the possibility of the toilet flushing causing a siphon is so much lower then with the old 3 or older 6 gallon flush toilets.

 

[jpm6621]

Thats what i will do Thanks for the input.