Help identifying what this line does

[GAplumbnovice]

Hey all, new to the plumbing world and for the life of me i don't know what this line is for or what it goes to. The bottom shutoff valve is the one I use to kill water to the whole house, I don't know what the valve above it is for. I can't budge it, so I'm not sure if it's stuck open or closed. Help!

http://tinypic.com/view.php?pic=35a291g&s=9#.XK-r8qR7mHs

 

[Diehard]

When you say the valve above it, I assume you are talking about the shut off to the right and above it.
I have to assume that the service is coming down from that pressure reducing valve that's directly above that lower valve. So then my first thought would have to be that the valve on the right may go out to an exterior hose bibb.
Have you looked for an exterior hose bibb and if so, does it work?

 

[GAplumbnovice]

Yes sir I was talking about the shutoff valve above to the right. There are 3 exterior hose points on the house, 2 branch off of sinks so its not them. The third is about 4 or 5 feet to the right of this valve (but the line runs to the left). The line to this exterior hose point comes out of the slab, so i guess its possible for it to run left but end up to the right. Does the color of the shutoff wheel mean anything? The lower is brown and the one in question is black. I can't turn the damn thing or I'd test the hose theory.

 

[Diehard]

I was thinking that if you had an exterior hose valve somewhere that was NOT working, that would likely indicate that the valve in question is in the closed position. In which case I would try a bit more force in the CCW direction.
Or just leave it be, unless that exterior hose valve must be used. You wouldn't want to break something unnecessarily.

I assume those are non-rising stem gate valves so you can't tell if it's open or closed.

Brown vs green handles doesn't mean anything to me.

 

[GAplumbnovice]

Here's a dumb question. I'm assuming that the water from the street is coming down from the top, going through the pressure reducer valve, then into the two shutoff valves. If this is the case, I should be able to cut the water to the house by turning the bottom valve, and since the shutoff in question is above the other one, if it does go to the hose then the hose should work.

 

[Diehard]

Here's a dumb question. I'm assuming that the water from the street is coming down from the top, going through the pressure reducer valve, then into the two shutoff valves. If this is the case, I should be able to cut the water to the house by turning the bottom valve, and since the shutoff in question is above the other one, if it does go to the hose then the hose should work.

That's exactly what I was assuming. I thought I was saying that in post #2.
EDIT: Yeah the hose should work if the valve isn't stuck closed.
EDIT2: Of course if it does work, that doesn't guarantee it's being fed from that valve in question. But likely is.

 

[GAplumbnovice]

Cool. The hose works now, so if I kill the main and it still works i then i know what that valve is for! Unless the main shuts the hose too and I'm back to square 1, lol. Thanks for your help.

 

[Diehard]

Cool. The hose works now, so if I kill the main and it still works i then i know what that valve is for! Unless the main shuts the hose too and I'm back to square 1, lol. Thanks for your help.

LOL True!
And then there are cases where some hose valves or irrigation systems are fed from upstream of the PRV.