How to Figure PSI at Sprinkler Systems
Automated sprinkler system kits make it possible to save money by installing your own system, however they need sufficient water pressure, measured in “psi,” or pounds per square inch, to operate various fixtures together each line of tubing. If you’ve never worked with water pressure or automatic irrigation systems, then you might want to rely on a professional coordinator; but if you are more sure of your abilities, you can find out the total pressure loss throughout your system to make sure that the previous rotor rotates.
Initial Survey
Call your local water department to get the static water pressure for your area. Based on your utility, sprinkler systems require 30 to 50 psi to power the system. When it is reduced — or higher — you must have pressure adjustment valves in your home water system.
Assess each exterior socket, or bib’s, water pressure. Turn off all the water prior to taking this measurement, such as toilets and other minor-use appliances. Attach a water pressure meter, available at many hardware stores, and turn the tap all the way at each bib to get an ordinary pressure.
Step Water flow rate at each bib by catching water in a large bucket for one moment. Measured in gallons per second, you can multiply the volume by 60 to get the flow in gallons per hour.
Record water pressure and flow, with a map drawn to scale of the region in which you plan to install your own system.
Add-On Pressure Decline Bodies
Draw out a preliminary sketch of the system utilizing manufacturer’s suggestions or recommendations from the agricultural extension.
Compute the pressure drop in the lines from adding together the pressure loss for each section and type of tube or pipe between each fixture, such as pressure regulation apparatus. As an instance, given a flow rate of 2 gallons per second, pressure would fall 0.75 psi along a 20-foot length of 1/2-inch type L copper tubing and 1.27 psi along a 20-foot part of 1/2-inch PEX plastic pipe, for a total of 2.02 psi loss for the whole 40-foot section.
Figure the fall for every single lateral and add it to the fall for the part of the primary line that feeds it. The most important line will experience pressure falls at the junction of each branching line, or lateral. The fall along the lateral must be added into the fall before the primary line continues to the next lateral.
Incorporate pressure changes for elevation. Each 1-foot change in elevation will make a 0.433 psi change in pressure. For instance; if the most important line falls 15 feet across the lawn, water pressure in the line raises 6.5 psi along its length, however a 15-foot rise would make a drop of 6.5 psi.
Add together pressure losses for each valve, sprinkler head, rotor drip emitter, spray and filter in each part of the system. Look on the packaging for this particular number or use a program that offers pressure loss.
