Water Flow Characteristics

時間：2016-07-09 10:38:36點擊：次

The friction loss in hydraulic flow can be evaluated through the use of various low coeficients. One such coefficient is the Hazen-Williams C factor. This factor for PVC and CPVC plastic piping systems has been set at C = 150. The following formulae express the friction loss in feet of water and the water velocities in feet per second.
Friction loss is based on the Hazen Williams formula

f － friction head loss in feet of water per100 feet of pipe
C－constant for inside pipe roughness (C = 150for
extruded smooth wall thermoplastic pipe)
Q－low in U.S. gallons per minute
di－inside diameter of pipe in inches
The value of C = 150 for thermoplastic pipe is based onengineering measurements made with new and usedthermoplastic pipe in several laboratories. Thus, thevalue of C = 150 has a conservative bias. Using C =150, the equation reduces to

Water velocities in feet per second V may be calculated as follows:

TYPICAL VALUES OF THE HAZEN-WILLAMS COEFFICIENT

APPROXIMATE FRICTION LOSS IN PVC AND CPVC FITTINGSIN EQUIVALENT FEET OF STRAIGHT PIPE