Laundry Sink Sump Discharge Question

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Sydflash

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I can't wrap my mind around how to tie the discharge of a laundry sink sump into existing plumbing.

I have come to the conclusion that the sump chamber needs to vent through the roof.

What I am having a hard time with is figuring if the discharge necessitates its own vent or do i need to make any changes to the existing drain's vent.

Here is a diagram I hope makes sense:

drain.jpg


The diagram may not make it clear that the sink in the basement must use a pump.

Does this look right? Can it be done this way? Is there a better way?

Will the pump force water up the kitchen sink drain? Can I put a check valve above where I cut in to prevent this, or will this wreck the venting?

Thanks for looking!
 

Cwhyu2

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Your picture is a correct way for your piping,you do not need the vent on the sump basin as it is grey water only, not waste from a toilet and you do not need to the vent vent the discharge as long as every thing else is vented properly.
 

Reach4

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I think you need your vent on the ejector pit and it should be 2 inches, or at least those are the rules around here.

The pump could fill the kitchen sink if the septic is clogged and the radials are clogged. If that happens, the stuff in your sink will probably be a small part of your problems. Don't let your septic tank get full. Get it pumped enough or more than enough.

I don't know about the check valve in the sink drain line. It sounds as if it could be a clog point.

I am not a plumber.
 

Cacher_Chick

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The diagram is correct under most U.S. plumbing codes.
The size of the discharge and basin vent required are dependant on the size of the basin and pump.
 

Sydflash

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left.jpg

This is the current set up. I eliminated some of the surroundings in hopes of making things make sense.

I want to have my washing machine empty into the sump chamber, making the drum trap obsolete.

I also don't really want to disturb the set up.

Can I just put a fernco cap on the trap and leave it?

Also, not labeled in the picture is the kitchen sink line I will be tying into is the copper pipe coming from the top left corner of the pic.

I've been told that where this pipe joins the main drain is an unusual layout - but it's worked for 50+ years now.

Does anyone see a problem with the sump water being pumped into this union? Could the discharge be throttled with a ball valve so as not to force water up the drain, or is this not really a problem?

A bigger question might be: Would it be better a better overall plan to eliminate the drum tap and tie the sump discharge to the main drain there?

Thanks again for any and all advise... what I thought would be an easy plumbing project has turned out to be one of my most challenging.
 

Cacher_Chick

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The problem with the kitchen sink is that it does not send the waste in the direction of flow. The non-shielded rubber fernco-style connectors are not permitted for that kind of use either. I would remove the existing washer drain and then cut the copper above to plumb in a wye for the drain pump. If I were going through that trouble I would cut in a wye for the sink drain and make that right too. You have a pretty simple job to do there, you just need to gather the right selection of pipe and fittings to make it happen.
 

Jadnashua

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Without a vent, the sump might have problems letting the waste come in. Something has to let the air out of the tank while adding waste.

You see the pipe offsets with those rubber couplings? That is the exact reason why they are not allowed above ground! You need those with the metal band around them for support. This means that you need to be more precise to get things aligned, but it also means you don't have that step and pipe end to catch crud along the way, or for a snake to poke a hole if one was ever used.
 

Sydflash

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... I would remove the existing washer drain and then cut the copper above to plumb in a wye for the drain pump. If I were going through that trouble I would cut in a wye for the sink drain and make that right too. You have a pretty simple job to do there, you just need to gather the right selection of pipe and fittings to make it happen.

Not quite following you. Where would you put the wye?
 

hj

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Sump pit covers SELDOM have 'sealed' covers. They just sit on the top of the basin to keep things from falling into it, so they do not need vents. But, whoever put that piping together was NOT a plumber. The ONLY time the pump would send water up to the sink drain, if the drum trap were removed, would be if the main line was clogged and that would be a bigger problem.
 
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Cacher_Chick

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I would cut in a wye on the horizontal section for the sink drain. The pumped line should be downstream, and could be installed in place of the existing washer drain.
 

Sydflash

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If it is in place of the washer drain - a new sealed pvc drain to the brass "t" - would I remove the drum trap?

Would I need a wye?

Does piping a sealed drain to that spot - removing the existing wye - change things?
 

Cacher_Chick

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The entire brass connection that was installed should be removed and the piping adjusted so that it all lines up on the vertical. The new wye can be installed there using the proper banded couplers.
 

Reach4

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That "drum trap", despite the appearance, does not look like a problem drum trap to me. Its output appears to be 2 inches above the input. A perforation will leak out on the floor. So I see it as a form of P trap. I am not commenting on the other aspects.
 
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