Please look at my washing machine/utility sink drain setup...need advice.

**Dave88LX** · 11-29-2011, 06:31 PM

Originally Posted by hj

quote; You also should not use a 90 degree elbow on its side in a drain line.

Interesting because almost EVERY DWV has a least ONE elbow on its side, and most have SEVERAL. Being "close" to a vent is NOT the definition of whether it is proper or not. Just because your refrigerator is next to the kitchen table will NOT keep it from going sour. In fact, the washer flowing past the sink drain is NOT the ideal configuration, and is FAR from ideal, but as I mentioned previously, it WILL work, but it is NOT how I would do it. The prohibition against a sanitary tee in a horizontal line has to do with the limited "sweep" the branch open has, compared to "Y"s and combos.

Here is what I ended up with. Go easy on me, first time using PVC for something other than a potato gun.

Still need to put a couple more hangers on it.

Open to any criticism/opinions.

**mtcummins** · 11-29-2011, 06:45 PM

HJ, are you referring to long sweep 90s on a horizontal drain line? I'm not sure if my county allows those (we have lots of dumb extra rules), but those I think are fine. I was talking about the tighter elbow, i think usually you guys refer to them as vent elbows. Sorry if I wasn't clear on that, I usually just call that a 90 and the other a long sweep 90.

I was told by local plumbers that we can't even use the long sweeps on their side in my county. As dumb as it is, we had to do a 45 and a street 45 to make a 90 turn, which is exactly the same thing, but has an extra potential leak point. yeah... dumb.

Looks like you have quite the mess of a project there now... Def want to get some kind of venting on that, even if you have to just do a couple AAVs (as a last resort). You might have a vent in there somewhere you can use, but its hard to tell (for me at least) from the pictures. The Line B... is there a kitchen sink, shower, tub, anything near there? Could this be a trap vent for a floor drain? Plumbers, can this be used if it is a floor drain vent, or would that overload it?

**mtcummins** · 11-29-2011, 06:52 PM

Sorry, was typing while you posted, so didn't see ur last one. I believe this is all correct, other than the whole wet vent thing... what you're using as a vent is in fact not a vent, so its still not done correctly. It will probably work ok, if whatever sink above that drains through that line is vented, but definitely still not up to code. If you were to have laundry draining while using the upstairs sink, you would probably have very little venting supplied to the laundry, and could end up with a siphoned trap.

**dlarrivee** · 11-29-2011, 07:48 PM

Nice job on what you did there, now we need to work on the vent though.

**Hammerlane** · 11-30-2011, 04:15 AM

What if Dave wanted or needed to have both washer standpipe and laundry sink drain on the same branch drain. And assume he had vent only above the stack. Would the following work?

**cacher_chick** · 11-30-2011, 04:24 PM

Originally Posted by Hammerlane

What if Dave wanted or needed to have both washer standpipe and laundry sink drain on the same branch drain. And assume he had vent only above the stack. Would the following work?

That would put the tee for the sink too high. Also, a vent tee is not a drainage fitting and should not be used on it's back.

**mtcummins** · 11-30-2011, 09:48 PM

unless i'm missing something, there is no tee being used as a drainage fitting, only as vent tie-ins. the pictures show some of them backwards and such, but I think they're being used correctly for their intended purposes in your drawing. in which case, yes this would work, if you could keep the sink drain low enough.

am i missing something?

**Yersmay** · 11-30-2011, 11:47 PM

MT,

I think I understand the logic of why the latest version will work, as you say it will, but I'm curious about your statement that some of the fittings are 'backwards'. For the life of me, I can't spot one that is backwards. For the purposes of ongoing education, can you indicate which? Thanks in advance!

**Dave88LX** · 11-30-2011, 11:49 PM

OK this is probably a goofy question but I will ask...washing machine supply hoses, how far open do you turn the spigot? All the way? I don't know if it's bad to leave it all the way open.

Thanks.

**Dave88LX** · 11-30-2011, 11:52 PM

Top vent SanTee backwards?

**Hammerlane** · 12-01-2011, 03:31 AM

Originally Posted by Yersmay

MT,

I think I understand the logic of why the latest version will work, as you say it will, but I'm curious about your statement that some of the fittings are 'backwards'. For the life of me, I can't spot one that is backwards. For the purposes of ongoing education, can you indicate which? Thanks in advance!

Not so much backwards but inverted. Like Dave said its the San-T that ties in the horizontal vent(which is the reason the San-T is inverted)...circled in yellow in the photo.

**Yersmay** · 12-01-2011, 07:15 AM

Hammerlane,

I've been under the impression that san t's are inverted if they are venting something. I don't know the reason for this, but that's what I always thought. Is this incorrect? Also, if the vertical pipe at the right of the picture is in fact a wet vent, does that dictate the direction of the san t inlet? Thanks again!

**Hammerlane** · 12-01-2011, 08:40 AM

Originally Posted by Yersmay

Hammerlane,

I've been under the impression that san t's are inverted if they are venting something. I don't know the reason for this, but that's what I always thought. Is this incorrect? Also, if the vertical pipe at the right of the picture is in fact a wet vent, does that dictate the direction of the san t inlet? Thanks again!

It's assumed that the piping above the inverted San-T is venting only. The inversion of the San-T is because think of the way the air would be drawn down. That inversion just helps the flow because of the radius on the San-T. The smoothest way for air to go down that line is if the tee is upside down.

If that is not venting only above that inverted San-T, I believe it is improper wet-venting because you cannot wet vent fixtures on different floors of the house.

I'm far from a plumbing expert but maybe one of the licensed plumbers can chime in and verify my statements.

**mtcummins** · 12-01-2011, 03:00 PM

Heh, wow. I didn't mean to cause some confusion here... i was simply referring to the pictures of fittings inserted into the image being backwards... the top left vent tee is sweeping the wrong way, as is the bottom left one. I also assumed that the poster knew this, and just didn't feel like inverting the images to make them in the correct orientation.