Bob wrote:
The check valve at the tank is so that house pressure does not put pressure
on the well system when the pump is off. The check valve at the pump is to
keep water in the well piping so you don't pump air every time the pump
starts.


snip

Good point. I overlooked that the OP does have such a set-up. I
really don't understand why it is done since it is redundant other than
in one circumstance. A failure of the checkvalve at the pump, install
one at the tank to obviate pulling the pump. Of course that does
result in air in the pipes problems.

Harry K


If you say so. I see no need to worry about "pressure in the well
piping". There are a lot more items in the residence that will fail
from pressure before anything in the well will. I have never seen a
system with both check valves and have never worked on such a system
which is why I overlooked to two valves.

Harry K