On Sunday, August 3, 2014 1:14:35 PM UTC-7, Pico Rico wrote:
"Harry K" wrote in message

snip

OK. Told the neighbor I would be using off their well. Turned on the
interconnect and then discovered that there was no shut-ff between the
pressur tank and my well. Neighbor would have been pumping right into
wherever my leak was.

didn't you have a check valve between the pressure tank and the well?

No. I know people think one should be there but it is redundant and does nothing but add restrictions to the system. The checkvalve goes in the well, normally just above the pump or it may be part of the pump.

One can be, however, installed between tank and well somewhere if the one in the well fails.

I saw a report somewhere where someone had installed multiple checkvalves in the drop pipe on a very deep well. No explanation of why they thought that was a good idea.

Harry K