Stormin Mormon wrote:
Discharge side near the pump. I've never know anyone to put a
check valve on the suction side. Always on the discharge.


If you did put the check valve on the suction side of the pump it would
have the same effect as the foot valve on a portable pumps drafting
hose. When a portable pump must pump against a high discharge pressure
it must also have a discharge side check valve and a pressure release
valve upstream of that check valve to allow the pump to start without
trying to start against the back pressure of the standing water already
in the discharge line. Submersible pumps such as sump pumps do not need
an intake check valve and if one is installed it will cause excessive
ware on the pump's motor by causing it to start under load.
--
Tom Horne

Well we aren't no thin blue heroes and yet we aren't no blackguards to.
We're just working men and woman most remarkable like you.