Size of PVC piping in relation to size of pump connections

[chase33]

Does the size of the PVC matter. I understand that ultimately the PVC must connect to the pump, but is there any other requirements as to the size of the PVC to and from the tank in relation to the size of the inlet and outlet size on the pump (which are 3/4 for the sump pump, and 1 for the closed loop pump)?

[tecwzrd]

Moved to hardware forum from SW forum:

Too large and it causes some friction (reduces gph), too small and it causes back pressure on the pump. I'd get the same size as the pump or no larger then 1/2" more.

[chase33]

thanks

[ellisz]

Some pumps will state the size of piping to achieve the rated GPH.

[PMaj]

Actually you get less friction using a larger dia. pipe. Being in irrigation repair it is know as friction loss, the smaller the dia. more the friction loss.

[MT79]

FWIW I know Mag-drive brand pumps recommend using plumbing that is twice the diameter of the output on the pump to get the best performance.