PAGOW 2 Pack 14 Inch (6mm) PVDF Wear-Resistant One-Way Check Valve for Fuel Gas Liquid Air, Micro Diaphragm Check Valve for Air Intake Feed, White

Blowing through it it seemed to have a high resistance but when I tested with water flow it worked fine.

Worked perfect

I ordered valves that was a bit to big but it looks like everything is still running fine

I have a Cpap machine and I use a so clean machine to clean mask,hose and water tank, I bought a filter kit with 4 filters and 4 check valves and every one of the check valves have failed and got water in my so clean machine, I used these check valves to fix my problem and they worked perfectly no more failed check valves and water getting in my so clean machine. If any body doubts a so clean you are very wrong this thing has saved me from getting sinus infections. I use to get 3 a year like clock work and in 5 years I have not had one and I credit that so clean machine…

tried both ways and yes it does flow 1 way but of the one's sent half leaked out the side. and all of them hindered water pressure and some didn't let anything through (yes i checked the direction of flow to see if they mis marked them, but no they just hinder the flow)

Works as well as the original.

My old Homelite XL chainsaw from the 60's needed a fuel and oil system rebuild. Unfortunately, both the oil tank and fuel tank had duckbill valves in them that had disintegrated. All I could find was that they are obsolete. Got these to try. They are much larger, but I put the oil tank one in the tank and ran extra line from the fuel tank for the other. I added a foam filter to the fuel tank one, and tucked it below the carb. All new lines and a rebuilt carb. Runs great once again.

I bought these for my brake bleeder setup. The check valves are well made and easy to install but are no good for oil. Do not buy these for any petroleum based fluid. The brake fluid has damaged the diaphram, rendering it useless. This product is no good for me but for anyone working with water or air, I think you will like them.

Worked perfect to replace check valve that broke on our hot tub pump. Fit perfect and was a easy replacement. Recommend putting the hose ends in hot water before fitting it on.

for medical grade valves they don't flow nearly the amount of air I was expecting. Not a happy purchase