Impossible check valve

thingiverse

I made this for my sump pump. It has a US 3/4" garden hose threads at the IN and a 3/8" (11mm) barb hose end. Inside there is a "ball" that allows flow in only 1 direction. I printed this on my Uniz IBEE Resin Printer for full detail. I used Siraya Tech build resin due to it's toughness. I have not tried to print it with FDM but I assume it can't be done on a well tuned printer. 0.05 mm layer heights would be the best bet. Supports: to ground only and printed with threaded side down.