This calculator is used to calculate pipe friction losses for straight
piping handling water and water with varying percentages of ethylene
glycol. The calculator uses an algorithm developed from the basic
principles of fluid mechanics. The program is based on the Darcy-Weisbach
equation, the Colebrook equation, and the Moody equation. The program is
intended for use only on straight piping. The program does not include
pressure losses due to elevation differences, or flow through fittings.
This calculator allows the user to input the fluid type, the fluid temperature, the
flow rate, the pipe size, pipe length, and pipe material. The calculator then determines
the velocity, the Reynolds number, the Moody friction factor, the pipe friction factor
(from the Colebrook equation), the pipe head loss, and the pipe friction loss in PSI.
This new version also calculates losses for fittings, valves, and
other losses which the user specifies. The new version calculates recommended control
valve coefficients (if a control valve is specified), and it also calculates total fluid
volume in the piping system (this is real handy for determining the amounts of water
conditioners to add, and to design expansion tanks). Please feel free to try out this
fabulous PlumbingSupply.US technical resource.
Please note that this method works for turbulent flow situations where the
Reynolds Number is greater than 3000. If you find that your Reynolds number
is less than 3000, you should revise your input parameters (increase the flow
rate and/or reduce the pipe size).
Additional Design Criteria: If your piping is being used in an open loop
system, flow velocities should be in the range of 5 to 10 ft/sec. For
closed loop piping systems, you should use a 4 ft/sec limit for piping
of 2" or less. For larger pipe sizes, use a limit of 4 FT of head loss
per 100 FT of pipe.