DISCHARGE MATERIAL vs PERFORMANCE (FRICTION LOSSES)
Another fact of nature, is that a liquid moving through a hose creates heat due to the friction of the two surfaces (water against hose). Steel pipe will produce more friction than will smooth PVC or vinyl pipe. Friction INCREASES with INCREASED length of pipe, or hose, or smaller diameter hose, and will DECREASE the discharge capacity (GPM).

The roughness of the hose/pipe is considered in Pump Select® calculations.