Plumping passive solar question

[gtm]

Hello folks,

I have a defunct passive solar system (thanks to the hurricanes of '04), but I hope to restore it soon, perhaps over the winter. I have to do some re-plumbing now, though, and am confused about something.

The return pipe comes out of the filter into a check valve and then to a T connection with a Jandy valve that allows you to send, or not send, the water through the solar panels.

Just downstream (maybe a foot) from the Jandy valve on the line going to the solar panels there's a pretty standard ball valve that does or doesn't allow water to flow along that line.

Why are both of these needed? It seems to me that either would force the water along one path of the other, but plumbing is not my strong point.

Thanks, Gary

 

[mas985]

Sometimes ball valves are used to isolate the solar panels in case of repair. That way water won't leak out if the pipes are cut or the panels are removed. Normally a check valve is used in that line which is sufficient to block backward flow but is not always used.

 

[launboy]

If all of the plumbing wasn't done at the same time, it might be a leftover part from a previous setup. When they changed or redid part of it they just left the valve there.

HTH,
Adam

 

[gtm]

Actually, all of this was installed at the same time by the guy who put up the solar panels. I never could see the sense of having two valves a foot apart on the same line, and wanted to check to see if I was missing something. But it sounds like it was just redundant.

I removed all of this stuff this afternoon and replaced it with a much simpler setup, which solved the problem I was having. I was mainly concerned about whether I needed this two valve weirdness when I finally get around to installing solar panels again. Sounds like the answer to that is no, but if you have any other thoughts I'd appreciate hearing them.

Thanks again, Gary

 

[JasonLion]

Solar diverter valves are often designed to be "leaky" so that the solar system can drain back into the pool when it is turned off. The ball valve would be used to provide a true seal to keep the solar piping from ever seeing any water.

 

[gtm]

That makes sense. When I cut everything out, it was obvious that the Jandy valve (the solar diverter?) was leaking slowly ... Thanks, Gary