Quote Originally Posted by foodchain
Be carefull. Simply reducing flow by restriction will increase stress on a pump.
I've always heard that restricting the input to a pump is hard on the pump, but not so restricting the output. Not trying to be argumentative, foodchain, just interested in learning what difference there would be in using a valve to restrict pump output by say 50 percent or using the same pump at some elevated level of head where it is pumping at 50% capacity? Whether it's mechanical restriction or gravity causing the rate of flow to change seems immaterial to the effect on the pump.