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.
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.
Test by blowing again.
The coupler and reducer should be glued together during final installation.