Replies

1. 
   DanH | Mar 14, 2009 07:07pm | #1

   Is it the check valve per se, or the pipe banging against the heating duct? Bracing the pipe so it doesn't touch the duct may make a significant difference.

   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
1. 
   johnp | Mar 14, 2009 07:47pm | #2

   Hi Dan . It is definitely the check valve.

2. 
   Jeff_Clarke | Mar 15, 2009 06:24am | #3

   If it's a metal (commercial-type) it will be very noisy.   PVC with rubber/plastic flapper is much quieter.   Sometimes you can help with pipe clamps/mounting method that is more resilient.  

   Jeff

3. 
   danz57 | Apr 04, 2011 09:56am | #4

   Sump Pump Hammering

   Hello All,

   I use a pvc swing check valve on our sump pump.   There is some water hammer going on with the valve.

   Pipes are all mounted walls and not vibrating or moving.

   Would a ball check valve or spring check valve reduce the water hammer ?

   Any input would be appreciated.

   Thanks.

   Dan

1. 
   DanH | Apr 04, 2011 07:06pm | #5

   You mean just a "clunk" when

   You mean just a "clunk" when the pump stops, or some sort of continuous sound?

1. 
   danz57 | Apr 05, 2011 10:18am | #6

   sump pump hammering

   Just a clunk from the flapper check valve when the pump stops.

   Wondering if a ball or spring check valve will not make the clunk noise.

   Thanks.

4. 
   BossHog | Apr 05, 2011 06:23pm | #7

   Where exactly is the check valve?

1. 
   danz57 | Apr 05, 2011 10:41pm | #8

   Sump Pump Hammering

   Check valve is screwed directly to the sump pump.

   There is no piping between the pump and check valve.

   There is about 14' of PVC from the check valve to the outside.

   Thanks.

1. 
   DanH | Apr 05, 2011 11:35pm | #9

   My impression (from just a few examples) is that the flapper style valves are a bit noisier on closing.  But they have the advantage of allowing more flow, and thus likely make the pump slightly quieter in operation.

   Gotta wonder why it's important, though. If screwed into the pump the valve should be inside the pit and most noise would be contained within.

1. 
   danz57 | Apr 06, 2011 10:16am | #10

   Check valve is in sump pit which is covered so hammering/clunk noise when pump stops is minimized.

   Just wanted to determine if is possible to further reduce clunk when pump stops.

   Thanks for info.

1. 
   MarkH | Apr 06, 2011 05:49pm | #11

   I can't say for certain, but an air bladder might help absorb some of the shock.

2. 
   BossHog | Apr 07, 2011 07:27pm | #12

   I wonder if you moved the check valve so it's farther away from the pump if that would help.   That way you wouldn't have a vertical column of water backing up against it.

1. 
   DanH | Apr 07, 2011 07:39pm | #13

   I'd say it's not broke -- why fix it?  Moving the valve upward would move it out of the pit and likely result in MORE noise.