Suction HWC:

Enter Suction pipe “Hazen-Williams Constant” (HWC). This is a number usually between 115 to 155 which relates to surface roughness of the pipe internal bore. Select Pipe Data at top of page and enter HWC into the text boxes.Experiment with the HWC value to simulate old pipe (guess-work only, try 10 -50 less than value for new pipe).