I made this at home after seeing that they are 15-20 dollars online and even more expensive at stores. I made it for around 6$ and had some of the stuff around the house. It worked perfectly for my compressor.

Step 1: Parts Needed

2- brass hose barbs (whatever size you need for air hose you're using) 1- brass coupler (same thread size as hose barbs) 1- pencil eraser 1- spring 1- rounded thumb tack 1- o-ring Super glue

Step 2: Determine Air Direction

Thread one hose barb into coupler. I made an arrow on mine to show air flow.

Step 3: Make Air Restrictor

Put pencil eraser into the spring and insert rounded thumb tack.

Step 4: Glue O-ring

Super glue o-ring onto other hose barb. Make sure it is slightly smaller than the rim of the barb.

Step 5: Assemble Parts

Put spring into coupler and screw in other hose barb. Make sure the thumb tack's rounded edge is facing the o-ring. This will create a seal when air tries to return to the source. You will have to experiment with the spring and torque of the hose barbs depending on the amount of air you are using. Stretch or compress the spring if needed. I tested mine up to 150 psi with no backflow. This is for inline application, but replace one barb with a nipple if you want to direct-thread it to a tank or other application.
<p>Very clever, the O-ring seal.</p>
Thanks! Sorry for the delayed response. I'm just now seeing this for some reason.
<p>Interesting concept. Sometimes you just have to jerry rig if they don't make the right sizes that you need. You may want to look into upgrading to a ball bearing instead of the pencil eraser and tack though.</p>
Thanks for the feedback. I looked around for a ball bearing, but thumb tacks were more readily available. It works great.
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thanks for the info, i tinker with odd projects (water and air) and I'm sure I'll use your idea for a few of my experiments.
Thanks for the info!
Very clever design, and well worked.
Glad I could help.
cheap brass barb fittings: <br> <br>https://sites.google.com/site/arctareproducts/home/industrial-parts <br> <br>
nice idea, im looking for the same idea but for my fuel line in my car, any ideas must take low pressure to open but still seal to hold fuel in the line when car is off.
I think this design would work with fuel if you knew how much pressure is needed and tested it with air first. There is a lot of trial and error with the spring in this design to get the right pressure. Also, I would check the corrosive properties of gas and the parts being used. Should be okay with brass I think.
Nice!&nbsp; I wish I had seen this (or thought of it) when I was putting together my air compressor manifold at home.&nbsp; I needed several, and I would have loved to save a few bucks.&nbsp; My setup: <a href="http://www.bolis.com/amillar/tools/air-compressor-tanks" rel="nofollow">http://www.bolis.com/amillar/tools/air-compressor-tanks</a>
Nice rig. I'm a big advocate of building things myself instead of buying them. Thanks for looking!
Nice solution, like you said you can get them online, even in smaller sizes, but for a bang for the buck you found an elegant solution. Good job and thanks for making this ible!
Great idea. I'll use it on my water pump
Let me know how it works with water. It seems like it will work...
That is awesome.
Thank you
This is fantastic! I hate how expensive check valves are also, but was never able to make a quality, perfectly airtight alternative. Thank you!
You're welcome. Let me know if you are able to test it beyond 150psi. That's all my compressor is capable of.

About This Instructable


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Bio: I was born and raised in Central Florida. I hold a bachelor's degree in business management and do network maintenance for a broadband/telecommunications ... More »
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