Thatís not exactly what will happen though. I though that for a while, too. If the water level is above the check valve the hydrostatic pressure will keep the water from exiting the last two joints of pipe. The other common the pump supplier made was that they also recommend the check valve be placed at the SWL. I think this is less advisable. A small change in static water level would cause the effect you spoke of.
Now that I think about it, I believe that Crown Pump (now Sulzer) has also recommended placing the check valve one to two joints above the pump.
Normally this placement is a real pain the butt, especially since we are using certalok drop pipe a lot. However, I believe there are now checks that will replace a certalok coupler. It still isnít as simple as thread the mpt x fpt check right into the discharge.
Moderator: Can we move the other pertinent discussion to this thread?