One Way Check Valve 1/8"(3MM) Hose Barb Non Return Ozone Resistance Plastic Valve for Water Fuel Oil Air Gas (Pack of 3)

I needed a check value for a low pressure application (delivery of an ethanol boost for octane increase). The valve slid easily into the 1/8" tubing I was using and it didn't leak. I used a 25ml syringe with a luer lock to test the check valve. Using water, I was easily able to push it through in one direction, while the other direction completely resisted any flow with no leaks. There is no indicator on the check value for the flow direction, but as you look at it, there is one side that is flared out which I assumed is the side on which the value opens indicating the direction of flow from the flat side to the flared side, and that proved to be correct. So far, these valve have worked flawlessly. I am aware that ethanol can quickly break down seals and tubing that aren't specifically rated for it, but these are being used for some non-critical experimentation. If I find that these check values fail at some point, I will update my review.

Needed low cracking pressure for aquarium dosing pump lines. I was able to fit 2mm ID silicone tube onto the 3 ml barb. Solved my problem of back flow. There is variation between these though. Some have almost no cracking pressure, while others take a bit more. With 4 dosing heads, and this 8 pack, I was able to add two on each line, one before the pump and another after.

I go this to allow air to vent a refrigerator water storage container, so it would easily dispense water without getting contaminated. It worked well for this purpose. These are small and have a barb for easy install. Only criticism was it didn't appear one of the valves quickly changed to the open position. But definitely this provides enough flow for my purpose and the price was excellent.

These were a great deal and worked like a charm!

Needed for a breather on my Harley

This small back-flow valve is specified to work at fairly high pressure. But there is no spec. for low pressure. In my case, the back pressure is 5 foot head of water or less than 3 PSI. In this case the valve leaked a lot. About 2 gallons per day. I even tried using two valves in series...still leaked. Check your situation before buying. Your case might work, but mine did not. Item returned.

Some may work some may not, some better than others

we got it in good condition, thank you

装置の真空引きをする時に、値段が安いので使ってみました。 圧力低いので、問題発生は有りませんでした。

Worked good for our windshield washer pump.

流体の逆流防止にと購入しましたが あまり良い結果にはなりませんでした