Washing machine + utility sink DWV setup

[eddd]

Setup I'm working with is below. If you look closely you'll see the utility sink on some angle iron "stilts" to allow for proper 1/4" per foot slope to the stack.


Unfortunately we'll need to use an AAV as I'm really not sure how I would vent it without.

I've heard some opinions that I should drain directly into the utility sink (to void overloading the AAV?) but as the discharge/p-trap is only 1.5" this seems not ideal.

My thought is to basically connect the 2 p-traps with a combo wye and then vent slightly downstream of that. So both fixtures would be sharing a studor mini-vent, which is apparently rated for multiple fixtures.

Here is a picture of what I'm thinking:


As there's also a 90-degree bend from the waste stack to the sink/washer, I was also unsure if I should use a 90 or (2) 45's, or some long sweeping 90 bend in that corner

Appreciate any feedback on this.

 

[Reach4]

I've heard some opinions that I should drain directly into the utility sink (to void overloading the AAV?) but as the discharge/p-trap is only 1.5" this seems not ideal.

The advantage of draining the washer into the laundry sink is that the sink adds a buffer if the 1.5 inch drain cannot keep up. You need a bigger drain if you run the washer into a standpipe.

 

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[eddd]

The advantage of draining the washer into the laundry sink is that the sink adds a buffer if the 1.5 inch drain cannot keep up. You need a bigger drain if you run the washer into a standpipe.

Forgot to mention that all pipe will be 2".
Currently the only 1.5" pipe is the utility sink p-trap. I think this would then connect to a 2" to 1.5" reducer immediately, connecting to the 2" drain.

 

[Reach4]

I am thinking this would work. You need to separate out the vents 6 inches or more above the flood level:

I think the 90 from horizontal to vertical can be a short or long sweep. I think the tee under the AAV can be a santee upside down from the way it would be oriented when connecting to a trap arm.

Even better would be to add a cleanout above where the pipe turns down. A clog would probably tend to be below the floor right below where the pipe turns horizontal after the vertical drop.

 

[eddd]

Hey that looks familiar to some other setups i've seen.

This definitely looks like a working solution i've seen just about everywhere, with a vent/standpipe for each fixture.
Do you know why this is the preferred method if according to code, for a 1.5" trap, max distance to vent is 6 foot?

I see this method of venting close to every trap a lot, seems like everyone does it above code for a good reason?
I'm not sure if I understand the code correctly, but would the original image i made still be considered passing? (even if not recommended?)

 

[Reach4]

Do you know why this is the preferred method if according to code, for a 1.5" trap, max distance to vent is 6 foot?

Are you asking why your picture doesn't do it? I think it would be because the vent to the trap arm would be a wet vent. I don't know what you had planned for that right-hand santee at the top. Was that a vent or another AAV?

I think the trap arm may not be considered a trap arm any more once the standpipe drainage gets added in. So I think you need a vent before that. I am not sure. I am not a plumber.

I'm not sure if I understand the code correctly, but would the original image i made still be considered passing? (even if not recommended?)

I don't think so.

 

[eddd]

I don't know what you had planned for that right-hand santee at the top. Was that a vent or another AAV?

Yeah didn't label that well, that far right tee is the waste stack (can see it in the real life picture sort of).

I think the trap arm may not be considered a trap arm any more once the standpipe drainage gets added in. So I think you need a vent before that. I am not sure. I am not a plumber.

Yeah I'm lost here, so tempting to try it both ways and figure out what the differences would be. But for now I'll probably just throw in that extra vent haha.

 

[Reach4]

Yeah I'm lost here, so tempting to try it both ways and figure out what the differences would be. But for now I'll probably just throw in that extra vent haha.

I expect your original would work fine, but maybe not. When the WM drains, it could have maybe have sucked the sink trap dry. I think it is not technically in accordance with US codes.