Sump Pump Discharge Line Bangs


  #1  
Old 08-05-13, 12:18 PM
F
Member
Thread Starter
Join Date: Jan 2009
Location: Kansas
Posts: 49
Received 0 Votes on 0 Posts
Sump Pump Discharge Line Bangs

When my house was built, the 1 1/2" discharge line for the sump pump in the basement was run up and then through the first floor trusses to the outside of the house. There is a backflow valve in the line near the pump, which is a pedestal pump.

The problem is that whenever the pump cycles and shuts off, the line in the trusses bangs, which is annoying to sleepers in the bedrooms below and above the line. When we get a lot of rain, the pump will cycle on and off about once per minute. We get a lot of water in the sump through the drain tubes around the footings.

I have installed a "T" where the line turns from vertical to horizontal to run through the trusses, putting a 12" long by 1 1/2" air chamber at the top of the vertical run, thinking that this might alleviate the bang. The effect was slight. I also put some foam padding under the line where it turns to go into the trusses so that it is not resting on a truss at that point. Again, no noticeable effect.

Would putting the backflow valve just into the horizontal part of the discharge line be better? I am guessing that what is happening is that when the pump shuts off, the column of water in the vertical part of the discharge line drops down an inch or two, and when it suddenly stops, the entire line bangs slightly against the truss members.

This has to be a common problem with an easy cure, but I am unaware of the answer. Thanks in advance for your advice.

Chuck
 
  #2  
Old 08-05-13, 11:07 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 62,542
Received 1,598 Votes on 1,473 Posts
It's usually the backflow valve closing that is causing that banging. The more water that sits on top of the valve when it closes makes it louder.

I would go to a plumbing supply and get a different check valve. They make ones that close slower and don't thump.
 
  #3  
Old 08-06-13, 05:45 AM
J
Banned. Rule And/Or Policy Violation
Join Date: Apr 2013
Location: USA
Posts: 4,294
Received 0 Votes on 0 Posts
Some things very wrong outside if a sump has to run that much to keep up.
Improper grading.
Mulch piled up against the foundation.
Flower beds forming ponds.
No, or plugged up gutters.
Outside drain tiles routed to the inside pit, big mistake if that's true.
Adding some expanding foam where the pipes run though the joist will hold the pipe in place and stop the banging.
 
  #4  
Old 08-06-13, 12:51 PM
F
Member
Thread Starter
Join Date: Jan 2009
Location: Kansas
Posts: 49
Received 0 Votes on 0 Posts
Thanks for the replies. I will try a different check valve that closes slower.

I am almost certain that there are drain tiles on the outside of the basement walls along the footings. The grading slopes away, but when it rains for a few days and the ground gets saturated, the sump will run relentlessly when the next rain storm dumps several inches.

It is standard practice to run drain tiles both outside and inside the footings around here. I am building a new house at present, and the concrete contractor did exactly that.

Regards,
Chuck
 
  #5  
Old 08-08-13, 05:21 AM
F
Member
Join Date: Feb 2005
Location: Northern New Jersey
Posts: 444
Received 0 Votes on 0 Posts
How does mulch piles up against the foundation impact this ?.

Just curious.
 
  #6  
Old 08-08-13, 06:08 AM
N
Member
Join Date: Jan 2012
Location: Canada
Posts: 2,743
Received 18 Votes on 16 Posts
I'm a little surprised I haven't seen this mentioned in the previous posts....
Sump pumps move a lot of water, very quickly. The sudden surge in pressure (or lack of) when the pump stops and starts will jar the pipe work, causing it to rattle and bang if a hard pipe through joists. If you've ever seen that a sump pump discharge through that cheap flex hose while it wasn't secured to anything, you'd see it dance around like a cartoon fire hose (maybe not lift off the ground though).

To the OP, is the discharge line a soft hose or hard (ABS or PVC) pipe?
You're two posts in the thread give no indication either way.

If it is hard piped (ABS or PVC), a vinyl or rubber coupler (one or two of them) installed at the bottom (and possibly one at the top) of the vertical pipe leaving the pump will act as a bit of a shock absorber and drastically reduce the impact of the stopping and starting of the pump. I suspect the rubber couplers you find in the plumbing section of the hardware store would do the trick. Try to use coupler(s) without the steal external sleaving. The idea is the coupler needs to expand and contract.
(We use this type of arrangement for intercooler piping on some turbo cars.)

For the remainder of the pipe work, secure it where ever possible. A rubber washer between the bracket holding the pipe and any lumber will help absorb some vibration (not all or a lot, but some).

If it's the black flexible hosing commonly found on sump pumps, couplers won't help (they are stiffer then the pipe). You will need to secure it. This flexible piping will require more support than regular pipe.
 
  #7  
Old 08-10-13, 05:33 AM
F
Member
Thread Starter
Join Date: Jan 2009
Location: Kansas
Posts: 49
Received 0 Votes on 0 Posts
The discharge line piping is 1 1/2" PVC, so there is no flex. I did find a check valve that everyone raved about. It is called the Brady, by Campbell Manufacturing, and is available on Amazon.

Some flex line would probably work, but would cost about the same as the Brady, and I like the security of some rigid line.

My pedestal pump does pump out a tremendous volume of water when the rains fall and saturate the soil. I tried submersible pumps, but like the pedestal for the sheer volume of water it can pump.

Thanks for the comments.

Chuck
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: