View Full Version : Check valve making a loud bang at end of cycle
Deanald
Dec 28, 2008, 03:03 PM
I just replaced my sump pump because the old one would not shut off and it was 8 years old. I had to replace the pvc piping coming out of the pump that comes up and out of the pit. I did not drill a 'relief hole' in the new pipe(the old pipe had one), could this be causing excess pressure that is making the check valve bang? If so where should I drill the whole, and does it matter at what angle it is drilled?
If not any suggestions? I've never had a basement before and I don't know if its time to bring a plumber out(I would prefer to try to fix it myself)
Milo Dolezal
Dec 28, 2008, 03:17 PM
This is more-less design problem. What's happening is that falling-down water column hits the check valve with such a force that it makes loud bang.
There are two things you should do:
1. Support any loose horizontal and vertical discharge pipe, especially if you have plastic sewer ejector drain
2. Install second check valve on discharge riser above sewer ejector, about 12" downward from the point where pipe turns from vertical to horizontal.
Deanald
Dec 28, 2008, 03:33 PM
Milo,
My check valve is not right off the pump. It is about 4 feet about the pit, and then goes up an additional 4 feet or so. Do you still think I should add a 2nd check valve?
Also, do you not think it has anything to do with a relief hole?
Thanks,
Milo Dolezal
Dec 28, 2008, 03:36 PM
Check valve should be installed directly on the pump. How tall is your riser ?
Deanald
Dec 28, 2008, 03:48 PM
I just installed the same way the old pump was in(the noise did not happen with the old pump, I upgraded from a 1/3 HP to a 1/2 hp if that matters). Not sure what a riser is... but here goes the info I think you need. The pit is about 30 inches deep, from the pit to the check valve is another 4 feet, from the check valve to the height before it becomes horizontal another 4 feet. So altogether it is pumping about 10ft up.
mygirlsdad77
Dec 28, 2008, 05:46 PM
What type check valve do you have? Brass, plastic, sping loaded(not likely on sump), wye check, straight check. I prefer plastic swing on sumps. Tend to make a lot less noise when pump shuts off.
Should really be no need for relief hole if all other piping is done correctly.
Deanald
Dec 28, 2008, 05:51 PM
Not sure, the packaging doesn't really indicate.
ProPlumber at Lowe's: 1-1/4" - 1-1/2" Sump Check (http://www.lowes.com/lowes/lkn?action=productDetail&productId=141964-15649-PPSPC-150&detail=desc&lpage=none)
Pleaes let me know if the link does not work. It's item number 141964 from Lowe's
mygirlsdad77
Dec 28, 2008, 06:08 PM
That's the exact check I use, and have had no issues with overly loud closing. Follow Milos advice about supporting(anchoring) of discharge piping.
Deanald
Dec 28, 2008, 06:15 PM
Everything seems anchored in good fashion. Any other ideas?
Milo Dolezal
Dec 28, 2008, 08:47 PM
Do you have plastic drains of Cast Iron?
I still think you should install 2nd check valve to break water column fall.
Yes, true is that some new pumps do not require 3/8" hole in the discharge nipple. They are suppose to be "self-priming". But since there is a problem with the new system, I would probably drill that hole near the pump discharge - and bellow the check valve - anyway. You have nothing to loose by doing that...
Deanald
Dec 29, 2008, 10:49 AM
Called the maker of the pump. The guy is positive need a 2nd check valve half way between my current one and the max height. Milo-perfect call.
Thanks, ill let you know how that works.
Deanald
Dec 29, 2008, 03:21 PM
2nd check valved solved it. Excited about getting a quiet night of sleep.
mygirlsdad77
Dec 29, 2008, 04:16 PM
Glad you got her fixed(with milos help). Take care.
truck 41
Dec 29, 2008, 06:31 PM
Hello, if you upgraded from a 1/3 to a 1/2 then you will notice a deference in the performance of the pump, sense your pumping more gallons per minute the head pressure will be more noticeable when the pump turns off.
sdkeywords
Jul 7, 2010, 03:05 AM
Check valves are two-port valves, meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various types of check valves used in a wide variety of applications. Ball Valves (http://www.valveindex.com/)
Milo Dolezal
Jul 7, 2010, 07:32 AM
Sdkeyworkd: welcome aboard. You are commenting on 2 years old thread...