Toller wrote:
I have a valve in the water line from the well to my seasonal cottage. It
is about 3' deep and is turned with a very long wrench. Each Spring I turn
it a quarter turn, and each Fall another quarter turn. It rotates all the
way around, so it can be a quarter turn either direction.

I was told that the turn in the fall was to allow the water line to drain.
The turn in the Spring is to run again; if I don't position it properly the
water system doesn't hold pressure very long.

It is getting very stiff and I expect I will have to dig it up in the spring
and replace it. I can't really picture what kind of valve it would be that
allows the pipe to drain in one position, but is open in the other. Anyone
know what it is? Maybe some sort of backflow preventer, but not like any I
have seen.
It is an hour drive to the nearest plumbing supply; I don't really want to
dig it up and take it to the store. I would be nice to have one with me when
I dig it up.

Thanks.

Jim is correct. It is a 'stop and waste' Turned one way it opens the
line to the house. The other way it blocks the line to the well and
connects the line to the house with a small opening allowing the water
to drain from the house. If you do replace it, get a 'stop and waste'
that has a stop on it. I think all modern ones do. They only allow a
90 degree turn then you have to turn it back 90degrees in the spring.
Your slow loss of pressure is due to your free rotation in either
direction. Unless you stop it exactly right, it isn't fully closing
the small hole. Your plumbing shop can show you one and you can see
what I am talking about. Much easier to understand the functions while
looking at one.

Harry K