Triple Sink: disposal backwash and noise

I didn't get your last message in time. Well…I got a bit messy with the glue. At least I kept it off the travertine floors.

On the right and center sinks I didn’t glue the pvc that runs into the adaptor at the bottom of the sink. I suppose I could have on the middle sink as the trap can disengage if needed. On the left sink, I added a few turn connectors which if glued would prevent the remove of the trap. I might install adaptors and non-schedule 40 pvc on the left sink vertical if needed. Also the center sink’s pvc pipe connecting the trap to the wye could have been shorter.

All in all, I’m not sure if it's ok for the traps to twist and turn the way I have them. I have no idea if this will pass code or hold up over time. I enjoyed doing it. it’s fun to try new things.

It was funny when I talked to the Home Depot rep. He gave me a weird look when I said I want to install 3 traps. He stated to say I didn’t know what I was doing. I told him I asked some plumbers on the internet and then all of sudden he says, “Ah yeah 3 would be the best way to go…”

So here’s some pictures, glue everywhere…. Wondering if I need to call a plumber in the morning.

Hope you never have to clean the drain line, because your not going to be able to do it from under the sink.

John

He can always cut in a wye with cleanout later.
I think he can skip the plumber though.

He's doing fine.

I hope the drain line never stops up, because if the sinks fill with water BOTH of them will leak where you connected the PVC to the sink drain fittings. Those threads are NOT "pipe threads" they are slip nut connections which need gaskets to prevent leakage. I am glad you had "fun" doing it because you turned a simple task into a "project". At least if you get frequent flyer miles from your credit card purchases, you realized some benefit from all the extra money you spent on it. If someone called me to unplug their drain, and I found a system like that, the first thing I would do would be to cut the pipe at the wall and discard the entire thing and start over. When I put it back together, I would follow Sinatra's advice and "Do it my way".

Yeah, the fittings at the sink tailpiece will be a problem. I didn’t install a gasket or tape the threads. Nor did I glue the pvc to the fitting. It will disassemble easy enough to put in the gasket.

Instead of gluing the pvc to the tailpiece connector I need for it to be able to disconnect. This way the trap can be fully removed if necessary. I am planning on trying to hunt down such a fitting. Something that basically allows two 1 ½ “ pvc pipes to be connected together and then removed and reconnected at will.

I wanted to use the thicker pvc as I was thinking it may help with disposal noise. Whether or not it really does, I don’t know. The disposal is much less noisy with this setup as it does not echo through the other drains nearly as much. Had I got your 2nd post in time saying not to use the union traps and the 40, I would have switched. It made the project more complex.

Getting frequent flyer miles is not happening as I don’t even own a credit card. Last time I had a Sky Mile card, I spent 3 times more money than I do now. Paying cash forces me to know how much money is coming in and how much is going out. All in all, I spent about $50 in parts and $20 in tools (not mentioning what I paid the handyman). I’ll return the unused parts.

What is valuable is now what’s under the sink is not a mystery. I understand a bit about the different types of pvc and how it generally fits together. Knowing this surely helps and may be useful again.

Thank you once again for your help on this. I would not have even tried to this without your help. I've enjoyed this project.

1. There is NO gasket which will work with those fittings to prevent leaking.
2. Dope, tape, or anything else will not do it either because the threads are NOT tapered, are NOT 'sharp/precise', and are NOT meant to have fittings screwed onto them.
3. Leaving them unglued just means they have TWO places to leak instead of one.

I don't like double wyes laid on the horizontal even if it is allowed, you can't get pitch on both sides. What I would do with your hook up is to use the dbl. wye and use one side for a clean-out, use the other branch for a new trap and hook up for the garbage diposal only, use the front of the dbl. wye with one trap to hook up the other two sinks, do it this way and you won't need baffel tees

Looks like I was too late with my idea, but you did pretty good. If you decide to change the connection to the two sinks it's not a big deal. Get yourself two kitchen sink tailpieces, two lock nuts, and two washers. On the pvc comming up get two pvc trap adapters; the nuts and washers come with them, measure first and cut off the pvc, glue the adapters on and install your tailpieces and snug the nuts up, that should allow you to take the traps off the two sinks if you ever have to, luck.

That sounds like a plan. I'll get the correct tailpiece connectors and secure these into pvc trap adaptors.

After installing the horizontal double wye, I see what you mean. I used a level to try to maintain zero right-to-left pitch. I think it will be ok till the next kitchen remodel.

In order to gain more cabinet space, I might reroute the center pvc. I’m thinking about doing a 90 out of the tailpiece and then running horizontal and then dropping into the trap which will be tied into the wye.

I’m watching Holmes on Homes. He’s fixing a house that had a crazy new hvac system. He had to completely rip out the old system and run a new system. In the process he had to lower the ceilings by 14”. By by 10 foot ceilings. I would pretty mad if I were the home owner. Wonder if he could have installed a series of room hvac units…anything other than installing bulkheads. The house looks horrible…after spending $100k some ceilings are now 7 feet.

I saw that episode too.
The ceiling looked pretty low for a big room like that.

There is no problem with a plastic double "Y", because there is more than adequate "slop" in the sockets to give as much pitch as you want to for the branch arms.

Here, and in other postings, I see plumbers comfortable with more than one trap on a trap arm. Yet, my 2000 UPC code book clearly states at 1001.1 that "No more than one (1) trap shall be permitted on a trap arm". Has this changed? Are inspectors passing it anyway? Is it allowed under other codes?

Plumbers who comment here regularly and are pretty adament on other parts of the code seem to let this one slide. I am just curious why.

As the originator of this thread, I’m sure it’s evident that I’m not a plumber. I did research the exact question before installing.

What it seemed like people were saying is the code allows for as many traps as sinks as long as each sink only goes through at most one trap. If the drain output of a sink travelled through 2 traps before leaving the building, this is a problem.

Since in my case each sink only has one trap, I think this passes code.

Double trapping is a different (and, to my mind, more serious) code violation. The 2000 UPC is very clear on the prohibition of multiple traps on one trap arm and 1982 THE UNIFORM PLUMBING CODE ILLUSTRATED TRAINING MANUEL shows a drawing of it and indicates that it is not allowed. The fact that so many here seem to think it is OK exactly is why I commented. I really am curious if the UPC has changed or if other codes allow it.

trap

It is an inspector issue, and most do not have a problem with it, especially if you could eliminate them by using a single trap and repipe it differently.

This weekend, I'm installing the correct sink tailpiece fittings. Terry mentioned that a cleanout could be cut in ever needed. So I’d like to add a cleanout now and am wondering which to use.

What I’m envisioning is changing the center sink tailpiece to come out horizontally and travels a foot or so and then turn 90 degrees down and connects to the trap. So I guess the cleanout would go on the vertical pvc above the trap?

Is this correct the place for the cleanout? Is the single wye or sanctuary tee the correct cleanout?

asktom said:

Here, and in other postings, I see plumbers comfortable with more than one trap on a trap arm. Yet, my 2000 UPC code book clearly states at 1001.1 that "No more than one (1) trap shall be permitted on a trap arm". Has this changed? Are inspectors passing it anyway? Is it allowed under other codes?

Plumbers who comment here regularly and are pretty adament on other parts of the code seem to let this one slide. I am just curious why.

Click to expand...

The trouble with codes is everybody is using a different one, or a different variant.
I'm sure there are codes thal allow multiple traps on a single arm.

There are also codes that allow that double wye laying flat, but the UPC dosen't (vent only).

I’ll let you know what our inspector says...if he even looks. The sink is working great. Disposal noise is much less and traps are saying full. I like this setup. Much less chance of the sink clogging up.

I'm confused about the placement and type of cleanout. Does it make sense to put a clean out on the vertical above the center trap? Wye, tee or doesn’t matter?

Hello,

First things first. I am saddened to hear about Terry. He was so helpful and friendly. I've only posted a few times and when he replied, it was special because he is "the man" that started all of this.

Second, the triple sink with the triple adapter has been in use since 2010. The sink tailpipes were fixed and it's operated perfectly. Never once was there a clog. There was one design flaw and I never put two and two together until a few days ago when I decided to yank it out and replace it with a space-saving system.

Ever since this was installed, there has been an ever-so-slight odor. It was hardly noticeable. I used schedule 40 P Traps and I think that was the cause. I think these traps are a tad bigger, maybe hold more water, are too sallow or something to that effect and they do not produce a good enough seal.

Also, one of the sinks is mostly used as a drying rack for things that do not go in the dishwasher, so water in the p trap might dry up or get old or something. This was not the only cause of the smell, though, because even after it was used, the odor persisted.

A few days ago, I put in a "Talea Double Kitchen Sinks Drain Pipe Kit" : (https://www.amazon.com/gp/product/B07JM8MPW3)
This has a single p trap. That's when I realized there was a slight odor and it was gone.

I think I was warned about using schedule 40. That was good advice!

The new space-saving system does a great job of saving space. The wife is happy about that.

After seeing this system and installing it, I like it. The middle connector tube does have a baffle in it. I think it will work ok, although I am a bit worried that it might clog. So I'm going to take it out and use this:


I like how the disposal can connect to a straight tube and the other two sinks can connect to a downward-sloping tube.