Thread: Check Valve? on drain / vent pipe

I found this behind a wall access panel directly behind the washing machine, just a few inches above the basement floor. I am sure this is where the washing machine stand pipe is connected, and the vent extends straight up vertically. Is that a check valve? If so, is that a problem? I have never seen a check valve installed on the drain / vent plumbing...



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Is there a sewage ejector pump located in the basement? Typically a one way valve is located on the discharge side.

Originally Posted by Raymond Wand

Is there a sewage ejector pump located in the basement? Typically a one way valve is located on the discharge side.

No pumps what so ever. This is a two story townhouse condominium with a basement connected to the city's gravity fed sanitary sewer system.

What floor is that setup on?

Originally Posted by ROBERT YOUNG

What floor is that setup on?

As I mentioned, what you see in the photo is just a few inches above the basement (concrete) floor.

Andrew,

It is an unusual configuration. Can't tell is valve is installed correctly by photo. And a elbow tied in before the valve?

Further questions -
Past problem with flooding?
Is there a back flow valve installed on the waste line?
Any other valves on basement fixtures?
Radon mitigation?

Definitely needs clarification as to purpose and legality. Purchaser should be advised as to the concern and should inquire of vendor, and/or seek further clarification by a licenced plumber before close of title.

Originally Posted by Raymond Wand

Further questions -
Past problem with flooding?
Is there a back flow valve installed on the waste line?
Any other valves on basement fixtures?
Radon mitigation?

No past flooding problems that I am aware of. It is common in this city for a backflow / backwater valve to be installed on the main waste line running out of the house to the sanitary sewer (but that is a large valve on the main horizontal waste line located below the concrete floor. No other plumbing fixtures in the basement except the floor drain. I've done thousands of inspections in this area over the last 10 years and I don't think I've ever seen a check valve, if that is what it is, installed on the drain / vent plumbing. The installation appears to have been well done, almost as if it was original, or done by a plumber.

There is a passive radon vent installed into the sump pit, but again, very common for the area and shouldn't have anything to do with the drain / vent plumbing.

I basically identified what it appeared to be, that it was not a typical installation, may not be installed in an "approved" manner, to ask for any information available from the seller, and consult a licensed plumber.

I was curious if there was another fitting that I wasn't aware of that I may have been mistaken for a check valve... Or if anyone else has seen anything like this, and why?

It is probably just a connector, and not a check valve.
That doesn't explain why it is there, but plumbers are known for their mysterious ways.
A cleanout or a slip joint would make a bit of sense.

In the basement it might be anti back water protection from being tapped down stream another waste discharge due to accessibility in the condo. In other words, non-compliant install.

Originally Posted by Andrew Kolar

This is a two story townhouse condominium ...

Robert's last post brought up a good question: is it a townhouse or a condominium?

A townhouse is under the residential code, a condo is under the building code and other codes (the MEP codes).

There are significant differences is various code aspects between a condo and a townhouse.

Originally Posted by Jerry Peck

Robert's last post brought up a good question: is it a townhouse or a condominium?

A townhouse is under the residential code, a condo is under the building code and other codes (the MEP codes).

There are significant differences is various code aspects between a condo and a townhouse.

Good point.

Originally Posted by Andrew Kolar

I found this behind a wall access panel directly behind the washing machine, just a few inches above the basement floor. I am sure this is where the washing machine stand pipe is connected, and the vent extends straight up vertically. Is that a check valve? If so, is that a problem? I have never seen a check valve installed on the drain / vent plumbing...

I am unclear why you think that might be a check valve. To the best of my knowledge, a downflow check valve needs to be spring loaded. Other than the flange, was there any widening of the pipe where a check valve would be housed?

Originally Posted by Gunnar Alquist

I am unclear why you think that might be a check valve. To the best of my knowledge, a downflow check valve needs to be spring loaded. Other than the flange, was there any widening of the pipe where a check valve would be housed?

It does resemble what a flanged version of these ( Spring check valve / threaded / flange / PVC - JC series - Shie Yu Machine Parts Industrial Co., Ltd. ) would look like from that angle - you would see the flange and the bulbous shape below the flange, similar to what is in the photo ... zoom in to 500% and you can see the shadows and bulbous shape somewhat.

That was my guess as to why he thought it might be a check valve.

I don't know why there would be one of those in that waste pipe.

Originally Posted by Jerry Peck

That was my guess as to why he thought it might be a check valve.

Resembles this type of check valve. Deluxe sump check valve.

• This sump pump check valve features:
  
  • Eliminates back flow from standpipe to sump pump basin
  • Design allows for maximum pumping capacity while reducing pump cycling and vibration
  • Less frequent cycling helps prolong pump motor life
  • 2 rubber sleeves
  • 4 stainless steel hose clamps
  • Allows pump to be serviced without cutting pipe
  • Designed for low pressure systems - 4.3 psi (10' of head)
  • Deluxe model shown left
  
  

Keep water from returning to the sump pit or crawl space after the pump shuts off with a Sump Pump Check Valve.
https://www.plumbingsupply.com/sump_...ck_valves.html

Tell me what you think.
check valve a.JPG

Andrew, what plumbing stations are to the right of the assembly? Either on the same level or the next level up. same level, garage utility sink? Upstairs or same level, a water closet, shower stall.

Technically the home is a condominium.

I am not sure that what is in the picture is a check valve. The portion of the fitting I can see, just resembled check valves that I have seen, and I am not familiar with any other plumbing fitting or connectors that look like this. However, that is part of why I posted this, in hopes that someone knew exactly what it was, and why it may have been installed there.

This pipe is inside of the wall behind the laundry appliances, and while I can not see it, I am sure the horizontal arm that comes of the T is the stand pipe drain. No other fixtures in the basement (other than the floor drain already mentioned). There is a 1/2 bathroom on the floor above the basement, and two bathrooms on the 2nd floor above that.

get a bar code/qr code app
or clear shot of bar code for later research
no more issue identifying materials

It may be there (and code required) to prevent sewer backups into the home (simple as that).

- - - Updated - - -

It may be there (and code required) to prevent sewer backups into the home (simple as that).

- - - Updated - - -

It may be there (and code required) to prevent sewer backups into the home (simple as that).

It would backup through the floor drain before that valve did any good...