hydraulics

Hydraulic Calculation

Did you know that computer generated hydraulic calculations perform a dynamic resizing gauged against the end of line pressure requirements of the sprinkler device. The computer is looking at the source pressure, distance from the source, and head requirement all at once. It then tests a pipe size model, looks at losses, and then passes or fails the configuration. On failure it up-sizes to the next logical size.

In a simple calculation it would appear that a 1/2" pipe will be able to deliver the required 3 gpm to the head in question. Indeed a 1/2" pipe can easily deliver as much as 9 gpm, however looking at the losses dynamically, it is found that the pressure losses place the head at only 20 psi instead of the required 25 psi. Up-sizing the pipe to 3/4" will raise the pressure to 25 psi when the water is moving through the pipe thus giving the required 3 gpm @ 25 psi.

Doing the hydraulics calculations long hand can give the same results, but on a large irrigation system this can be laborious and time consuming. This leads to guessing and shorts cuts. Often pipes are up-sized as a general rule thus driving the overall cost higher. If the hydraulic calculations are ignored, and the improper sizes used the irrigation system will not function properly. You will have high output at the front of a section and low output at the end. The error can be so bad in some situations that the heads will not operate.

Computer generated hydraulics are fast and easy. The accuracy is superb. The system installation has no guess work. Field modification and recalculation is quick. Installers have accurate material lists to build by, and the As Built prints can be in your hands in short turn around.