Expert4PVC Consulting

Flow Velocity & Friction Head loss

Pipe Diameter:
Pipe Material:
Flow Rate: (GPM)
Pipe Run: (ft)

Pipe I.D:
Wall Thickness:
Roughness Coefficient:
Flow Velocity:
Friction Head loss:
System Friction Head loss:

This calculator generates information on the friction head loss of various piping, sizes, materials and flow rates used in water distribution systems. It offers several standard commercial sizes of pipes, although all combinations of pipe material, Schedule or SDR (wall thickness') may NOT be valid!

• Basis of Calculations •

The values calculated are based on NOMINAL pipe dimensions and the Williams-Hazen formula, shown above and published by the Plastic Pipe Institute TR14 March 1971.

• • Water Velocity • •

In general, flow velocity *LESS* than 5 feet per second, is considered to be "SAFE". Higher velocities may be used in cases where the operating characteristics of valves and pumps are known so sudden changes in flow velocity can be controlled.

• • • • Caveat • • • •

The information and calculations provided are based on data which we believe is reliable. Expert4PVC Consulting, however can not take responsibility for the information or data contained herein and no warranty of performance for any specific purpose or particular installation of any product is expressed or implied from this calculator. Results based on the equations shown and parameters entered.