Ball valve on return line - is this necessary?

[robrinker]

I'm in the process of replumbing the return line after my filter to add lines to the solar panels I'm attempting to add to my setup.

Currently, there is a single union ball valve on my return line immediately after my filter. The non-union side of the ball valve is solvent, and there's not enough pvc between it and the mipt fitting that screws into filter to salvage it. I'm not a plumbing expert, but I can't think of a good reason for it to be there. I can't imagine it would be good to 'throttle' the amount of water the pump was sending back to the pool. The union part of it is helpful for winterizing and removing the filter from the system entirely when I clean it. Should I replace this ball valve with a plain old union, or should I replace it with another valve?

 

[JasonLion]

It is very nice to have a valve near there if the filter is below the pool water level. It is also somewhat handy, but hardly critical, to have a valve there when doing a full tear down cleaning out of the filter.

 

[robrinker]

I think something just clicked for me...perhaps you can confirm.

When my water level is higher than halfway up the skimmer, if I try to clean out my pump basket after vacuuming, the water would always overflow out of the basket. I tried to prevent this by closing the valves to both my skimmers and my main drain, which helped, but I still had some overflow. If my equipment was outside, it wouldn't be a big deal, but it kind of makes a mess indoors.

I never considered closing the valve on the return since it was a good 2 feet higher than the pump. Maybe water was backflowing down the return line? If so, I should probably keep a valve there...

 

[dmanb2b]

you got it

we have our return ball valve right before the return fitting....you can see my old set-up, pre swg here

http://s702.photobucket.com/albums/ww30/dmanb2b/