they are called an 'air admittance valve' the whole purpose is to allow air
in and not vent water or gasses out. BUT one is not needed on a sump pump
setup.


s


"RepairNovice" wrote in message
...
On Thu, 10 Jul 2008 08:35:51 -0400, "CL \"dnoyeB\" Gilbert"
wrote:

| | /\
| | | Water flow
| |
| | | |
| | / / (In line air vent)
| | / /
| / /
| /
| /
| | /\
| | | Water flows this way
| |


That's very odd. Which way does the water flow? This is the water
leaving
the sump and exiting the house right? Wouldn't the water just flow right
out of the air vent? Whats the point of an air vent here?

I have added info to the diagram above.
I wondered about water going through the air vent too.
But the guy at the store explained that it has a special shut-off
valve to prevent water flowing through.


My setup also does not have an air vent. But I did add a clean-out pipe
to
it that should hold some air which should reduce the hammering a bit. Not
sure how well it works for that purpose.

clean-out plug
__ exit house
\ \ | |
\ \ | |
\ \ | |
--- ---------------| |
| --------------------|
| |
| |
| |
pump