使用 Hazen-Williams 公式计算泳池水泵系统的总动压头 (TDH)，输入管径、长度、流量和配件即可正确选型。
Total Dynamic Head (TDH) is the total resistance your pool pump must overcome — a sum of static head (vertical lift) and friction losses in pipes and fittings. Use TDH with a pump's performance curve to pick the right horsepower and flow rate.
Enter your pipe diameter (1.5 to 3 inches), straight pipe length, flow rate in GPM, static head in feet, plus the number of 90° elbows and check valves. The calculator uses Hazen-Williams for PVC (C=130) and adds equivalent pipe length for each fitting.
Keep suction line velocity below 8 ft/s and discharge below 10 ft/s to reduce noise, pipe wear, and cavitation. If velocity is too high, upsize the pipe. For most residential pools, 2-inch plumbing is the sweet spot.
TDH是泵在系统中输送水所必须克服的总阻力，包括垂直高度（静扬程）以及管道和过滤器中的摩擦损失。
您需要TDH来读取泵的「性能曲线」。如果泵相对于TDH过小，加热器或盐电解槽将无法获得足够的流量。
您可以通过使用更大直径的管道、大流量阀门并保持过滤器清洁来降低TDH。较低的TDH意味着用更少的电力推动更多的水。