NATIONAL DIVERSIFIED SALES INC 1720C20 2" SWING CK VALVE UNION CLR

Size and threading were exact match for my existing pool swing-check valve. Only needed to unscrew the rings for the existing value, drop this one in, and then re-tighten the existing rings. Replacement could not have been simpler.The new valve included the PVC slip connectors and threaded rings to allow the valve to be cut in, but I did not use them as valve fit the old connections perfectly.

For applications where the flapper is facing down, like mine, it did not work, as gravity was taking over the flapper position even with some pressure on the out flow. For pools, use a spring loaded check valve, 0.5lb works for me.

Pretty cool to have a see through valve. Although the novelty wears off.Easy enough to cement during assembly.

This check valve is suppose to be blocking the return flow, but this particular one does not do the job properly. Our Spa empties probably 1/3 once the pump is off. Wish i purchased a better quality valve.

Pool system

Spa began to drop down to pool level, recall that happening once before and called our pool fellow to come over; he replaced the check valve. Figuring it was the same thing I looked to see where the check valve may be, figured it out searched on amazon and purchased this one. The one I removed was different; springs, one of which had broken vs this one which is a flapper that closes when the water starts to flow back. Literally a 10 minute job. Back off the coupling on both ends, slide out the old slide in the new and tighten the couplings. Turn on, check for leaks, turn off and watch spa drop to water pool level and stay there.Update, ahter a few weeks I saw that the spa level was sown a bit lower than normal, today down much more. A defective unit perhaps?

My old valve control started to leak air at the union. The pump could not prime because too much air intake. This one is a perfect replacement, I can use the old unions to connect the swing valve. The valve does not close completely sometime as shown in the picture. The water will drain back to the pool until 1/2 left in the valve. I am lazy sending back to get the spring valve because this is working for me. Also my pool is salt water, the spring may get rust and broken fast.

I didn't install this as new but just replace the existing one and reuse the union. The only complaint is the thread, which is different from other unions.