3/8" Fuel One Way Check Valve Inline Non Return, Aluminium Alloy Fuel Line Check Valve for Fuel Line Diesel Gasoline Water, Black (10mm OD,2PCS)

These inline one way fuel check valves are simple little components that do exactly what they are supposed to do. If you are dealing with fuel drain back, loss of prime, or pressure issues in a low pressure system, these are an easy and effective solution. The aluminum construction feels solid and well finished. They are lightweight but not flimsy, and the anodized coating looks like it will hold up well against corrosion. The internal spring and seal work smoothly, allowing flow in the correct direction and stopping it cleanly when it needs to. Installation is quick and straightforward. Just pay attention to the arrow direction and slip them into place. The 12mm size fit properly on standard 1/2 inch lines, and once clamped, they stayed secure without leaks. They work well for fuel systems using gasoline or diesel, and they are also useful for other low pressure applications like water or air. Performance has been consistent, with no sticking or hesitation, and they have held pressure reliably since installation. Value for money is good, especially since you get two valves in the pack. It is always nice to have a spare on hand, or to use them in multiple locations if needed. The only reason this is not a full five stars is that these are meant for low pressure systems only, so they are not suitable for every application. As long as you use them within the specified pressure range, they do their job well. Overall, these check valves are simple, durable, and effective. They solve a common problem without adding complexity. Would I recommend them? Yes. If you need a reliable inline check valve for fuel or other low pressure systems, these are a solid option that work as advertised.

1 of them worked for a minute and the other didn’t work at all. I took the apart and the springs to hold the seal were not in place. There’s nothing to keep the springs in place. I took the spring plate out and used a punch to add a dimple in the middle to keep the springs in place. That should have been done when manufactured. I definitely won’t buy them again.

I installed this 3/8" inline one-way check valve on an older truck that had a problem with fuel draining back to the tank when the engine was off. After adding it into the fuel line, the system held prime and the truck started quicker after sitting. The valve body appears to be aluminum and feels decently built for the price. Barbs were sized correctly for standard fuel hose and it installed easily with hose clamps. Flow direction is clearly marked, which helps avoid installing it backwards. So far it has worked well for preventing fuel bleed-back and seems like a practical, inexpensive fix for older diesel or gasoline setups that lose prime.

These appear to be well made and will do the job that I got em for! I plan on using 1 of em in my main fuel line to keep all the fuel from draining back out so the electric pump won't lose its prime! This is on my project car, and I don't wanna have to be buying more pumps than I need to!!

These arrived for another shop project and they look great out of the box. The bodies appear solid and nicely finished, and the flow-direction arrow is clearly marked. This is a 2-pack of inline one-way check valves, designed to help prevent backflow and pressure loss in low-pressure systems. The specs are just what we needed: 0.2-6 bar (2.9-87 psi) working pressure and a wide operating temperature range. They’re listed as compatible with gas/diesel/water/oil & air but not for methanol or corrosive fluids. We’re installing them this week, so far everything looks correct and well-made. I’ll update if anything comes up during install or in use but overall recommend so far.

These check valves might be ok if you don’t really want them to stop all the fluid from draining back, because they don’t seal properly. Instead of using a ball to check the fluids, they are using a rubber disk. I blew air through the fitting and immediately saw that the disk was offset and cocked sideways. I tried to blow harder and it finally say back down but the disk was still not sealed because it’s too small to fully cover the hole when a slight misalignment happens. So for a functional standpoint, these won’t work. When it comes to the outer construction of the fittings the aluminum is standard for parts that are this cheap. The ridges on the barbs are not sharp or raised very high. The threads that hold the halves together are acceptable. The body seal doesn’t leak under low pressure but it’s not very durable because it did get cut up some after disassembling a few times. The color of the anodizing is nice and black with a laser etched arrow to show direction. If I had to pick something good, it would be that the check valve opens easily due to the light spring holding the flapper. This would be good in low pressure situations which is the only thing I would use these for. I don’t think these are a very good value because they don’t adequately do the job they were designed to do. I would pass on these and any design that is like these unless you just need the flow slowed down in reverse flow and not fully checked.

My freeze dryer uses the drain line not only to remove water but also to let air back into the chamber to relieve pressure. On more than one occasion, the drain hose was accidentally left in a bucket of water, which then got sucked back into the chamber and nearly ruined a batch. While this valve won’t be used in that specific setup, I tested it by pulling a full vacuum in the chamber and then opening the drain valve. The check valve did not leak at all, and the vacuum was fully maintained. It performed exactly as expected. Based on that test, I feel confident using this check valve in another application.

I wanted to stop drain back from my fuel pump to the tank, so I installed one of these and it didn't work at all. I got the other one and could easily blow air back the wrong way. Took it apart and discovered a really bad design in there. It's some kind of a disc style valve which is not designed right and definitely not made to work right. Material is bad. Installation doesn't work. Connectivity has nothing to do with a fuel valve. They fit the hose, but that's about the only thing they got right. I don't recommend getting these because they don't do the job. A check valve has to stop backflow, get your act together guys!