Check valve or One Way valve for micro irrigation system. Works with 5mm diameter flexi irrigation pipes.

One way valve allows flow in direction of rounded side of valve only. Consists of 3 parts, 2 parts form the casing that connects to the 5mm diameter irrigation pipes. The 3rd part forms the valve that seats into the squared section of the casing. It should be placed with the sharp point into the hole. The rounded casing is then glued into the other casing. For effective sealing push a thin rubber sheet over the valves sharp point and cut out to the size of the valve. Some silicone will also work, to create a good seal between the valve and seat.

For high pressure applications a ballpoint pens spring can be cut in half and inserted over the 5mm diameter slots on the rounded casing part and back of the internal valve part. This will require more water pressure to open the valve, but will seal the valve significantly better when shut.

I found that this part is more effective when printed on a resin 3D printer.