Quickun 5/16" One Way Inline Check Valve, Non Return Hose Barb, Ozone Resistance Plastic Valve for Fuel Oil Water Gas Pump Air, 2 Pcs

If you are confused on which direction is in and out don’t try blocking through with mouth! I used a 3/8 piece of rubber hose adapted to a water line to test because I couldn’t blow through with my mouth 👄, wide side in small side out 😊

Perfect for preventing backflow into the bucket of bleach from the backstream injector I use with my power washer. These are cheap but effective check valves for use with 3/8" tubing.

I have a kit to add a half gallon or gallon jug of dish soap under the sink. It kept draining back into the jug and it took 1000 pumps to get the soap back to the top. With one of these is stays at the top. Can also be use on he water line that runs to an ice maker.

My soap dispenser is working again! The piece that came with my soap dispenser kit eventually wore out.

I’m not sure what happened. I’ve bought check valves for my ozonator before and never ran into this issue. These were more expensive than others but I thought that would equate to more durability. I bought a two pack and gave one to my neighbor. He never got it to work (ie the water goes clear in 24 hours). I put the other one in my tub with the same result. Taking it out I tried to blow into the inlet…it seemed clogged but finally broke free. I reinstalled it, didn’t work. It split open when I tried to remove it again and the plastic seemed brittle. As you can see the inside was covered with this white hard powdery material like it had been installed for months. I don’t know if Amazon sold me returned merchandise or what but I CANNOT recommend this product.

These valves take a bit of pressure to open. they were not as sensitive to opening pressure as i needed. but they are quality pieces.

These are the real deal and they really work in your automotive windshield washer lines.

Of course, when you read about it being ozone resistant, one thinks this could be good for using on a spa to prevent back-flow from the ozone supply to the water injector. Sadly, one thing that's VERY difficult to obtain for this product, is the amount of pressure required in order for the gas to flow in the proper direction. With respect to a spa ozone maker, that amount of pressure it can produce is insufficient to cause this check valve to open. I bought the five pack thinking they would be perfect but for me, they're useless.

Good valve

Worked perfectly for my purpose. Only problem is that it's not marked which direction it should flow and a check valve only works one way. I just blew through each opening to figure out which direction would prevent air from going through before installing it.

Bateaux

Great little valve

Check out my picture. The hours is 3/8" ID (see labelling on hoes). Compare to labelling of the package these came in and the one connected to the hoes. 🤨