Under window kitchen sink vent

[morrison.jas]

does this look ok?

the kitchen sink is under a window on a load bearing wall so I can really only go down to the crawlspace with the pipes. fortunately, the main drain line is located close to the ground level in the crawlspace so i have about 3' to play with between the floor and the drain. my concept is to run the sink drain down far enough to bring a drain up from the horizontal run and then send it horizontally over to a shared 2" vent in the laundry room wall. the laundry room and kitchen are both clean slates right now but ultimately i need the 3 drains in the locations shown. there is an old vent pipe in the room about 5' from where i have my roof vent shown. i'd prefer to tie my new vent to that old vent in the attic and just have 1 roof vent.

my main concern is with the kitchen sink vent, I suppose if the drain clogged after the vent, i could end up sending water up the drain pipe until it would end up going down the washer drain line instead.

 

[Terry]

If you're doing an Island vent, it high loops before going down. The venting takes place at the level of the trap arm, not below the floor.

Or you can use an AAV like in the picture below.

And how it's normally done with a vent continuing through the roof.

 

[Sponsor]

 

[morrison.jas]

like this instead?

 

[Terry]

That looks better. You might check with the inspector though as to whether he allows that or wants the vent through the roof on the outside wall.
Normally the Island vent is used when you don't have a way to go straight up. In Washington State I'm seeing a lot of new construction going to the AAV now. Things keep changing in plumbing. I plumbed hundreds (maybe thousands?) of homes before the AAV was being used. For a while I was plumbing five homes a week with a three man crew.

 

[morrison.jas]

do you think AAV is as good as the island vent config? I thought there were still a lot of people who hate AAV's for some reason or another.

BTW, do the rest of my pipes look ok? I think they are pretty simple but i would still like to ask!

no inspector for this job. just a DIY remodel out in the sticks.

 

[Terry]

The drawing looks good.
AAV's do need replacing after a while and for this reason need to be accessible. An atmospheric vent is best because it's a two way vent, air goes in and out, and doesn't need replacing.

 

[morrison.jas]

where would i need to put cleanouts in this system?

 

[Terry]

where would i need to put cleanouts in this system?

Kitchen sink,
Washer,
Foot vent for loop

 

[Plumber69]

does this look ok?

the kitchen sink is under a window on a load bearing wall so I can really only go down to the crawlspace with the pipes. fortunately, the main drain line is located close to the ground level in the crawlspace so i have about 3' to play with between the floor and the drain. my concept is to run the sink drain down far enough to bring a drain up from the horizontal run and then send it horizontally over to a shared 2" vent in the laundry room wall. the laundry room and kitchen are both clean slates right now but ultimately i need the 3 drains in the locations shown. there is an old vent pipe in the room about 5' from where i have my roof vent shown. i'd prefer to tie my new vent to that old vent in the attic and just have 1 roof vent.

my main concern is with the kitchen sink vent, I suppose if the drain clogged after the vent, i could end up sending water up the drain pipe until it would end up going down the washer drain line instead.



View attachment 49338

what program is this

 

[morrison.jas]

what program is this

I modeled it in ProEngineer. Not really the best tool for this type of work but its what i know and have access to through my work.

 

[jaydub2010]

That looks better. You might check with the inspector though as to whether he allows that or wants the vent through the roof on the outside wall.
Normally the Island vent is used when you don't have a way to go straight up. In Washington State I'm seeing a lot of new construction going to the AAV now. Things keep changing in plumbing. I plumbed hundreds (maybe thousands?) of homes before the AAV was being used. For a while I was plumbing five homes a week with a three man crew.

The drawing looks good.
AAV's do need replacing after a while and for this reason need to be accessible. An atmospheric vent is best because it's a two way vent, air goes in and out, and doesn't need replacing.

so there are different types of AAV's? If the AAV is two way, how would you create the vent piping under a sink to keep gases from coming back up and out the AAV? Maybe I don't understand the AAV very well.

 

[Terry]

"SPECIFICATIONS The purpose of an Air Admittance Valve is to provide a method of allowing air to enter the plumbing drainage system without the use of a vent extended to open air and to prevent sewer gases from escaping into a building. An Air Admittance Valve is a one way valve designed to allow air to enter the plumbing drainage system when negative pressures develop in the piping system. The device shall close by gravity and seal the vent terminal at zero differential pressure (no flow conditions) and under positive internal pressures."