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Pressure Loss Calculator for PVC Pipe
This is a Java-powered friction loss calculator. You must have Java installed on your computer to use it. If you don't have Java installed, click here to download it free from Sun Microsystems.
Pressure loss in pipes may also be called "friction loss". Both terms are used in the irrigation industry. Both terms refer to the drop in water pressure that occurs when water moves through a pipe. For much more on pressure loss and how it impacts water flow see the Sprinkler Design Tutorial.
Instructions:
- Select type of PVC pipe.
- Select pipe size in inches.
- Enter GPM flow through this section of pipe.
- Enter the pipe length.
- Click on calculate.
If you don't see a blue box below, your browser may have blocked the Java script from running. Look at the top of the page for a message warning that your browser has blocked the script from running. Follow the instructions for allowing the script to run. If that still doesn't correct the problem you likely do not have Java support installed on your computer.
- Friction loss calculations are for standard PVC pipe.
- Cl 160 PVC pipe is not commonly available in 1/2" size, therefore the calculator assumes that Cl 315 pipe will be substituted.
- Cl 200 PVC pipe is not commonly available in 1/2" size, therefore the calculator assumes that Cl 315 pipe will be substituted.
- Cl 160 PVC pipe is not commonly available in 3/4" size, therefore the calculator assumes that Cl 200 pipe will be substituted.
- This calculator uses a contracted form of the Hazen-Williams formula which is the industry standard for calculating friction loss.
- A conservative C coefficient of 140 is used for PVC pipe (many authorities use 150 which is risky as it leaves no margin for error).
- Velocities over 7 feet per second should not be allowed in PVC pipe.
- Velocities over 5 feet per second should be avoided, especially with pressures higher than 80 PSI, or in pipe larger than 2".
This program is Freeware and may not be sold.
Java programming by Dan Rasmussen, methodology by Jess Stryker, ©1999.
There is also a stand-alone Win95 friction loss calculator created by Steve Granger. Use the value of 1 for both the Specific Gravity and Viscosity of water when using this calculator. Under the heading Material, "Plastic" is PVC plastic. The current version doesn't work for poly plastic. The windows calculator will calculate friction losses for galvanized steel and pipe materials other than plastic. Download the calculator from http://www.IrrigationTutorials.com/LineSize.exe. Many thanks to Steve for creating this calculator and providing it free for everyone to use.
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Text and Images by Jess Stryker unless noted. Copyright © Jess Stryker, 1997-2009. All rights reserved.
