Originally Posted by gradioc
DO NOT PUT PVC NEAR THE PUMP. Pvc melts. Pumps get hot. Threads slip out. My rule is 12" of metal between the pump housing and first pvc. That's probably excessive, but I've seen too many pvc males melt out of pumps.
If your PVC is melting then you have a problem with your pump deadheading and boiling the water within the pump case... This is not the fault of the PVC but in the design of your system.
PVC works fine threaded at the pump when you dont get a deadhead situation. Even when you use metal, If you get a deadhead situation, you have more than just the piping to worry about as typically the mechanical seal is now scored and needs to be replaced.