Do I even need a check valve on this sewage pump set up?

Reply

  #1  
Old 04-15-19, 11:27 AM
Member
Thread Starter
Join Date: Oct 2014
Posts: 565
Do I even need a check valve on this sewage pump set up?

So, my not very old pump is tripping the GFCI breaker. Which means a bad seal or something I assume, I'm going to take it to get looked at.

Anyway since I have to pull it out it's time to deal with the fact that I installed an inappropriate type of check valve which doesn't even work (probably because it's not appropriate)

The type of check valve they want to sell me is very expensive (~$150)

But looking at the plumbing I'm wondering if having one is even necessary.

The pump plumbing goes up and joins the main drain line here



The other end of that T is just capped off after a short (~2.5 ft) section. Not sure why, maybe to reduce turbulence?



So the top of the pump stack is at least 10 vertical feet above the main waste line clean out. I the drain ever backed up far enough to get to the point where it was coming down the pump outlet we'd notice well before hand and would dealing with bigger issues.

So is an check valve really needed here?
 
Sponsored Links
  #2  
Old 04-15-19, 11:32 AM
Member
Thread Starter
Join Date: Oct 2014
Posts: 565
Just to add, the water in the pipe currently flows back into the pit since the check valve thats on there is jammed open or something. It raises the level a couple inches but wouldn't seem to meaningfully increase the amount of cycles since it's set up with a pretty long float at the moment.
 
  #3  
Old 04-15-19, 12:03 PM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 19,334
I don't see any check valves in your photos.

I would use a check valve. It limits how much liquid drains back into the sump every time the pump runs. In some cases that drain back can be a pretty big percentage of what the pump moves out... only to have flow back in.
 
  #4  
Old 04-15-19, 12:30 PM
Member
Thread Starter
Join Date: Oct 2014
Posts: 565
Pilot Dane- The check valve (that doesn't work) is just below the frame of that picture.

Is the drain back the main reason to use a check valve?

Some rough math:

1.5 M depth of pit + 3 M to the top of pipe * 39.37(inches per meter) = 413 inch of height. That length is about half 2" and half 3". So we have aprox pi*206+( 1.5^2)*pi*206 = 2103 cu in of liquid.

2103 cu in ~ 34.5L which is only about 7% of the design capacity (500L) of the pit.

I'm trying to decide if it's worth spending the money on. If it were your house would you spend the $150?
 

Last edited by Esand1; 04-15-19 at 12:45 PM.
  #5  
Old 04-15-19, 04:37 PM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 19,334
Yes, a check valve's primary job is to prevent the uphill pipes from draining back into the sump. I don't know what valve you are considering but the ones I've used are closer to $30. One thing to note is that most check valves make a "clunk" sound when they close. Some people find the sound offensive.

---
Thank you for calculating your pipe's volume that will drain back. I was running a rough number in my head based on your photos.
 
  #6  
Old 04-15-19, 07:03 PM
Member
Thread Starter
Join Date: Oct 2014
Posts: 565
Pilot, this is what the plumbing store is trying to sell me. It's from the same manufacturer as the pump.

https://www.electromecanicamm.com.ar...0515103926.pdf
 
  #7  
Old 04-15-19, 07:19 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 49,519
That looks like a well built check valve..... hence the high price. We don't know what retail locations you have nearby to purchase from as your not in the States.

Normally an 1-1/2" would be used but your pipe is larger.

2" check valve

Nothing says you must use a check valve. If you don't experience short cycling then you should be fine the way it is.
 
  #8  
Old 04-15-19, 07:31 PM
Member
Thread Starter
Join Date: Oct 2014
Posts: 565
The pump has a 2" port. The submergible pump was actually a replacement for the original surface mounted pump which had a 3" port that was installed when the house was built but when we moved in and found the pump dead everyone told us that the submergible pumps were better....after this issue with a pump just a few years after buying it I'm not so sure....
 
  #9  
Old 04-15-19, 07:54 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 49,519
I hadn't seen an original problem in the first post.

Sounds like one of the seals let water in. Yeah.... not good for a relatively new pump.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes