HOMEWERKS 2 in. Solvent x 2 in. Solvent Schedule 40 PVC Spring Check Valve VCKP40E8B - The Home Depot
Check Valve PVC Swing - Irrigation Direct
1.5" PVC True Union Check Valve, 1-1/4" Slip Swing Full Port Utility Check Valves, Sch80 Socket Pool Ball Check Valve for Backflow Prevention, Irrigation Systems : Amazon.de: Garden
4" Industrial PVC Swing Check Valve (S x S) SK-SC-040