|Posted by Don Hans on January 27, 2003 at 11:26:00:|
I have a sewage ejection system in my basement (below floor basin, sewage ejector pump, check valve). As indicated in many other threads here, the check valve bangs annoyingly when the pump shuts off. I have tried EVERYTHING to dampen this noise, but I cannot get it to stop banging.
I have temporarily removed the check valve, and the pump works fine (and silently).
My question is why do I need a check valve? It's obviously not to hold prime on the pump (which is submerged). And if any sewage does not make it all the way out the pipe on a pump cycle, and returns to the basin, who cares?
In the manual for my pump, it recommends a check valve if using as a sump, but optional for a sewage system. It also indicates that in freezing conditions, not to use a check valve at all.
Why do I need a check valve in this system?