What is this valve for?

[rinaldok]

Hey everyone, I'm going to be replacing everything on my equipment pad and I'm trying to plan it all out.

I have this valve on the return line, but I really don't know why it's there (and the handle was removed so obviously it wasn't intended to be used with any frequency).

Is it perhaps some kind of backflow prevention, to block the return in the event plumbing needed to be serviced?

I was considering replacing this with a FlowVis meter when I replace everything.

Thoughts?

Thanks!

 

[mknauss]

Is your pool equipment above, below, or at grade with your pool water level?

 

[rinaldok]

Is your pool equipment above, below, or at grade with your pool water level?

The ground is basically level from where the equipment pad sits to where the pool is. So the water level is at least 6" below the base of the pad.

 

[mknauss]

OK.. There is a small line next to the return line you are talking about. Where does that go? Is it needed?

 

[rinaldok]

OK.. There is a small line next to the return line you are talking about. Where does that go? Is it needed?

That's for the aerator.

 

[mknauss]

Do you have to close the valve on the main return some to make it work?

 

[rinaldok]

Do you have to close the valve on the main return some to make it work?

No I've never touched that valve (lived here for 2 years now), it's never even had a handle on it. Aerator works fine on its own (though I rarely if ever use it - I have a hard enough time keeping pH down).

 

[mknauss]

Hate to keep asking questions. But I wonder if the valve is partially pinched now and it is to make the aerator work. When you close the aerator line, does it impact your filter pressure any?

If not, then you don't need it.

 

[rinaldok]

Hate to keep asking questions. But I wonder if the valve is partially pinched now and it is to make the aerator work. When you close the aerator line, does it impact your filter pressure any?

If not, then you don't need it.

I just realized that the aerator is open in the picture - I took this picture while the pool was shut down for the remodel and the prep crew opened that valvle. It's normally closed, as I said I basically never use the aerator.

However to answer your questions I just went out and tested two things.

1. Opening/closing the aerator does not have a significant effect on filter pressure. The needle wobbles a little when I open or close the valve, but it settles back to basically the same pressure (extremely miniscule difference if any, well within a margin of variance for such an old pressure gauge I'm sure).

2. I took the handle off of the 3-way diverter on my suction lines and put it on this valve to see where it was oriented - it's fully open (which I confirmed by slightly closing and then reopening it).

 

[mknauss]

Great. I do not see any need for that valve then.

 

[rinaldok]

Great. I do not see any need for that valve then.

That's what I thought, but then I started to think that if someone put it there, they must have had a reason...

 

[mknauss]

It could be so they could direct more flow to the aerator.
Or
They could close that valve and the suction side valves and lock the water in the system. Why? To keep the water in it when they clean the pump basket? Easier to prime? Don't know.

 

[rinaldok]

It could be so they could direct more flow to the aerator.
Or
They could close that valve and the suction side valves and lock the water in the system. Why? To keep the water in it when they clean the pump basket? Easier to prime? Don't know.

Well it seems like the ideal spot to toss in a FlowVis. [emoji41]

 

[proavia]

Is that the only return line to the pool - in addition to the aerator line - or is there another one just out of the picture on the left side? Any water features? It appears there are remnants of a label on the 90 just above the valve.

 

[rinaldok]

Is that the only return line to the pool - in addition to the aerator line - or is there another one just out of the picture on the left side? Any water features? It appears there are remnants of a label on the 90 just above the valve.

That is the only return (it feeds 3 return jets). No water features. The stuff off to the left is the suction lines.

 

[proavia]

Yeah, that valve makes no sense then - unless you're trying to blow aerator water into the neighbors yard.

 

[Arizonarob]

Just a thought. It’s good to have that valve to isolate the system from the pool water for repairs. Since your re-plumbing the pad, I would turn that 2 way into a 3 way with a hose port off to the right. That way if you had to drain water from your pool from rain, repairs, etc, you would have an easy way to do so.
2-cents.