How do i properly use a ball valve

[chknlly]

Okay I need to backwash to waste, but I am not sure if the I have a "main drain" line. In the past I've just plugged one skimmer and used the other and vaccumed that way. Now I've searched and found that some recommend closing the "main drain" valve, where the heck is that?

I bought my house several years ago and the pool came with no manuals or anything. So I've been searching, hiring pool companies, using pool school, and yes, winging it sometimes with the functions of these parts (chlorination, cyclonic ball valve, sand filter, and pump). I'm including two pics so you can see what I mean. I have a ball valve, but I'm not quite sure how to use it. Thanks a million!

 

[Bama Rambler]

That's a 3-way valve and it's hard to tell but it appears to be connected to the suction of the pump on the back side.

The way it's turned now the pump is pulling all the water from the pipe coming in the top of the valve. If both skimmers are working then most likely the main drain is closed off like it is now.

If you turn the valve the opposite way it should stop the skimmers from working and open the main drain. Try it and see if that's what happens.

 

[chknlly]

I'm attaching a better photo. The way it is it's on 1/2. If you turn it to the red "full" line that is under port 1, which comes off the top, the blue is port two which comes up from the bottom it sometimes slows the water coming into the skimmer. There is also an "off" option that I am not sure what it is for (you can barely see it to the left of the handle). Not sure what the ports are though. I haven't had a chance to turn the valve sideways because I'm in the middle of vacuuming out to waste, but I will try it.

 

[Bama Rambler]

Turn it full one way and see where the water comes from, then turn it the other way and see where it comes from then. Post back what you find out.