Thread: check valves on basement sink drains

I have never seen a check valve on a sink drain. There a 3 of them in the basement of this newly rehabbed townhouse in Philadelphia.
The implications are obvious, but what I want to know is, are these valves even meant for this kind of use?
check valve.jpg

Originally Posted by John Arnold

I have never seen a check valve on a sink drain. There a 3 of them in the basement of this newly rehabbed townhouse in Philadelphia.
The implications are obvious, but what I want to know is, are these valves even meant for this kind of use?
check valve.jpg

That would make me wonder why "newly rehabbed". I don't know the answer to your question, but a bad experience has probably led to this solution!

Originally Posted by John Arnold

I have never seen a check valve on a sink drain. There a 3 of them in the basement of this newly rehabbed townhouse in Philadelphia.
The implications are obvious, but what I want to know is, are these valves even meant for this kind of use?
check valve.jpg

Its a good question. I do not know for certain, but suspect that a typical check valve used in a sump pump discharge pipe would not be approved for this use. Besides the fact that this would be a significant obstruction in the drain piping, I think the standards for sewage backflow would be more stringent. I briefly looked on the internet for sewage backflow valves and found 1-1/2 and 2 inch models. They have an internal flapper that does not significantly obstruct flow. The link below shows the valves (see page 41). If you Google the brand and replacement flapper you can see what the flapper looks like. Maybe it is also somewhere in the catalog.

http://www.canplasplumbing.com/Porta...s/US08_CAT.pdf

Originally Posted by Mark Reinmiller

Its a good question. I do not know for certain, but suspect that a typical check valve used in a sump pump discharge pipe would not be approved for this use. Besides the fact that this would be a significant obstruction in the drain piping, I think the standards for sewage backflow would be more stringent. I briefly looked on the internet for sewage backflow valves and found 1-1/2 and 2 inch models. They have an internal flapper that does not significantly obstruct flow. The link below shows the valves (see page 41). If you Google the brand and replacement flapper you can see what the flapper looks like. Maybe it is also somewhere in the catalog.

http://www.canplasplumbing.com/Porta...s/US08_CAT.pdf

I don't see a P trap in the photo? Is this someone's idea of eliminating the trap? You need a trap.

Originally Posted by Phil Cybolsky

I don't see a P trap in the photo? Is this someone's idea of eliminating the trap? You need a trap.

I did not post the photo, but it looks like there is a trap at the right side of the photo.

Improperly Installed & open Electrical junction box.

Originally Posted by Phil Cybolsky

I don't see a P trap in the photo? Is this someone's idea of eliminating the trap? You need a trap.

There is a trap.

Originally Posted by Billy Stephens

Improperly Installed & open Electrical junction box.

Yep, I would say that it is a rehab due to flooding from some source. I have seen this many times in homes that have been flooded. They install factory made cabinets that do not match the depth of the old cabinet box and the outlet box sticks out like that. If they come back and use a "pancake" or slim-fit box that usually takes care of the problem.

Why would you expect a check valve to function as intended when installed in the horizontal position?

Originally Posted by Eric Barker

Why would you expect a check valve to function as intended when installed in the horizontal position?

A lot of check valves are allowed or even required to be installed horizontally. The quote below is from a distributor's website:

No metal parts in any of the assembled elements eliminating possibility of corrosion
Suitable for both domestic and commercial sump pump applications
May be installed vertically or horizontally
Chemical-resistant PVC construction
Easy to turn on/off handle
PVC temperature rating: 125 psi @ 72°F
Click here to see an image of the internal workings of the Checkmate valve
Proudly made in the USA USA flag button

Sump check valve. Probably used as a backup in case the sink in the basement isnt used much which can cause the trap to dry out.

Originally Posted by John Arnold

I have never seen a check valve on a sink drain. There a 3 of them in the basement of this newly rehabbed townhouse in Philadelphia.
The implications are obvious, but what I want to know is, are these valves even meant for this kind of use?
check valve.jpg

My daughter owns a 4 plex rental. We recently renovated some of the units, and had a kitchen sink removed, with the drain tee exposed. When the upper apartment drained their sink, water flowed (splashed) from the tee, into the kitchen were we were working. Obviously not a swept tee. This water rush also caused gurgling in the sink, before we started the renovation. The check valve would stop the back flow from the upper level. Alternative, and preferred fix, is to replace the tee with a swept design. However, the check valve is an effective fix.

I agree with the intent to stop waste water from backing up from the streets. It's something you don't see everyday, but if you had raw sewage coming out of your sink, putting in check valves doesn't sound so bad. I think everyone who has basement fixtures should do this.

In the OP photo the check valve is installed improperly. The flapper hinge must be set to the top, as pictured the check valve is canted at an angle, and we are not sure if the hinge is near the top, sides or bottom.

In the picture here you can see Zoeller labeled the side that needs to be up when in the horizontal position.

checkthisside up.jpg

Originally Posted by Griffen

I agree with the intent to stop waste water from backing up from the streets. It's something you don't see everyday, but if you had raw sewage coming out of your sink, putting in check valves doesn't sound so bad. I think everyone who has basement fixtures should do this.

Bad, so brainy smurf is into plumbing now. I would note it, due to liability.