Remove S Trap and Add AAV

[Mugatu300]

Hello, have a question regarding kitchen sink plumbing. If I leave as is, its a classic S trap. I'd also like to add an air admittance valve. Any suggestions?

I was thinking of maybe cutting the PVC off low and then have it 90 towards to back right corner of the cabinet before bending it back upwards. Therefore, I could get the PVC a little bit further away from the center of the sink so I can extend the trap arm length. Does that sound OK? And if so, where should I add the AAV? Do I add it along the trap arm or above and in line with the PVC? I've seen people do it both ways.

Thanks!

 

[Reach4]

You may not need to jog the drain line, unless that pipe is so close to the back wall of the cabinet.

Where will the tailpiece be? Would it be where the black tape is?

Two 45s would be nicer that two 90s, if you can do it.

 

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[Mugatu300]

You may not need to jog the drain line, unless that pipe is so close to the back wall of the cabinet.

Where will the tailpiece be? Would it be where the black tape is?

Two 45s would be nicer that two 90s, if you can do it.

Do you think the trap arm in this pic is 3"? That looks like a similar distance between the PVC and sink center so maybe I can get away with not moving the PVC. Also, what is code for AAV height in relation to everything?

 

[Reach4]

Do you think the trap arm in this pic is 3"? That looks like a similar distance between the PVC and sink center so maybe I can get away with not moving the PVC. Also, what is code for AAV height in relation to everything?

I think the vertical thru the floor is 2 inch (OD 2.375 inches, and the trap arm 1.5 inch (1.500 OD).

AAV should be at least 4 inches above the trap arm. AAV must remain accessible to be changed.

Trap arm is from the output of the U of the trap to a point on the sanitary tee where the water tumbles down. That must be 3 inches or more for a 1.5 inch trap; if less than 3, you have a "crown vent" (search term for you). The U of the trap can swivel to become under the tailpiece. Having the trap arm inline with the tailpiece may not work for you, because you need that 3 inch +

I just picked a photo I thought was close to your situation and solution. There are others that show a jog. A jog can be above the santee or below. If above the santee, you must stay within 45 degees of plumb, and the AAV must be within 15 degrees of plumb.

I would avoid your idea of two 90s below the santee. Not out of the question, but I think there are better alternatives.

Buying a slip joint trap to experiment with will help visualize your plans.

 

[Mugatu300]

I think the vertical thru the floor is 2 inch (OD 2.375 inches, and the trap arm 1.5 inch (1.500 OD).

AAV should be at least 4 inches above the trap arm. AAV must remain accessible to be changed.

Trap arm is from the output of the U of the trap to a point on the sanitary tee where the water tumbles down. That must be 3 inches or more for a 1.5 inch trap; if less than 3, you have a "crown vent" (search term for you). The U of the trap can swivel to become under the tailpiece. Having the trap arm inline with the tailpiece may not work for you, because you need that 3 inch +

I just picked a photo I thought was close to your situation and solution. There are others that show a jog. A jog can be above the santee or below. If above the santee, you must stay within 45 degees of plumb, and the AAV must be within 15 degrees of plumb.

I would avoid your idea of two 90s below the santee. Not out of the question, but I think there are better alternatives.

Buying a slip joint trap to experiment with will help visualize your plans.

Thank you. Also, is it ok if the AAV is oversized? Was going to pick one up rated for 24 DFU which is probably overkill for just a kitchen sink but just want to make sure that wont cause issues.