3 drains near the top of my disappear edge basin

[jesse-99]

My pool has a disappearing edge. The edge's water basin (I call it the lower pit) can hold around 1,800 gallons of water. There are 3 drains, about 2" below the coping pavers, that are meant to drain water out of the lower pit -if- the water level were to get too high and overrun on top of the patio. The two blue arrows show 1 of the 3 drains -and- shows the adjustment knob for the drain located in the coping paver.


I *thought* the adjustment knob controls whether the drain actually allows water to pass through it or not (some kind of air/vacuum thingy I don't comprehend?) depending on if the knob is closed tightly, or opened (which seems to allow air through it based on the holes in the unit)


However, water will drain through the 3 drain holes, whether the adjustment knob is opened, or closed tightly. The 3 o-rings have all been replaced on each of the 3 different knob pieces, but that didn't help or change anything. Water will still evacuate out the drain if the plastic screw-in piece with the 3 o-rings is opened or shut tight. So, I'm looking for help in understanding HOW these 3 knob/adjustment things are supposed to actually work, and what is supposed to happened if the 3 knob adjustments are opened, and what is supposed to happen if they're closed?

(to prevent water for going out the the drains right now, I have to plug the 3 drain holes)


Can anyone help me understand the proper way they are supposed to operate?

Thanks,
J

 

[ajw22]

I am not sure that those valves have anything to do with your pit overflow lines.

Does your spa have an air blower?

Those look like the valves that control air flow to spa jets when there is not a blower. You use the valve to turn air bubbles on or off to a spa jet.

 

[jesse-99]

Nope, no air blower. and the upper spa is about 50' away in distance and 20' away in height from those 3 valves All 3 of those valves are directly in line with those overflow drains of the lower pit however as you can see in the picture, so I assume the valves and drains are related. ? appreciate the reply!

 

[jesse-99]

Bump, anyone else have an idea on this one?