Bang, check valves and ball valves in sewage pump application

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Max E.

New Member
Nov 8, 2019
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Hello to all, my first post and hope I the right place.

We had a sewage ejector pump installed when we had the house built (12 years ago) for a future bathroom in the sub-cellar. Head is about 10-12 feet, piping is 3". Current pump is a Zoeller and current check valve is a 3" Zoeller cast iron installed vertically right above cover. Currently only a plastic slap sink has been connected to it. And no issue other than a "large" bang after it finishes pumping and if feels like it will break the pvc (or something) one day if it had regular use.

Now that I have time to start working on the sub-cellar, need to tackle the bathroom and summer kitchen while a mess can be made (open up concrete floor etc), re-do some of the PVC work and possible move the basin location (a bit). We will have a kitchen sink, and 3/4 bath connected to this sewage pump.

So my first question is can PVC check values be used for sewage pump applications, like this one "Sanking SK-SC-030"? Any benefit with using a cast iron versus PVC? e.g. the Zoeller never needs replacing?

My second question is it better to have a ball valve with unions built-in or seperate? (since they never installed a ball valve; thankfully no actual bathroom was installed so no sewage in the lines), and which do you recommend.

I found the following that seemed interesting but would have to add union separately: Van Enterprises 3" PRO SERIES- 2PC PVC Ball Valve with STAINLESS STEEL Handle and CHROMIUM ABS Ball

ERA Sch 80 3 Inch True Union Ball Valve (Are these all PVC handles reliable).

Recommendations are appreciated.


Well-Known Member
Aug 19, 2017
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North Reading, Mass.
I would discuss your concerns on banging with Zoeller, including whether they use rubber type seats, etc.
Also their thoughts of possible advantages to horizontal mounting for the check valves. Particularly for sewage applications.

True Union Ball Valve has many advantages. Full port, replaceable seat, replaceable handles, with threaded or socket ends, etc.

What model Zoeller pump? I'd like to look at performance. Head vs flow. what's your difference in elevation(approximate) between the sump pit and the point of termination of the pressure pipe. Does it change to free fall in a larger pipe or pumped directly to a septic tank?

Vent size?