There are not many cheap check valves at the hardware shop. Since I'm only testing some pump application, I need to have lots of low medium pressure check valves. Here's a cheap way to make one.
Items needed :
1. 3/4" PVC coupler
2. 3/4" to 1/2" PVC reducer
3. Approx. 1" long pin (see diagram)
4. Few glass marbles
5. PVC pipe glue
Follow the steps or please download the original image for bigger viewing and reading.
The commercially brass type check valves are better for prolong usage. This DIY cheap check valve is only for my testing purposes. Any DAMAGES/INJURIES/DEATH due to this design, I'm not responsible.
Thank you for viewing.
Insert glass marble into the 3/4" side of the reducer. Smoothen he inside of the pipe if the marble doen't fit. Test the airtightness by blowing or immersing in water. Test a few marbles and choose the best.
Measure the location of the pin location, approximately twice the diameter of marble. Or it can be any dimension so long as it is within the reducer length. Should have room for the marble to move.
Poke a hole on the 3/4" side of the reducer. This to accomodate the pin which will be the rest for the marble during back flow.
Insert the pin, and finished it off with a well flushed finish with the outer surface of PVC pipe.
Make sure the pin is tight fit.
Finally, insert the coupler. Make sure the laps are airtight, and the coupler totally covering the pin area.
Test by blowing again.
The coupler and reducer should be glued together during final installation.
MarkJ5 made it!