Troubleshooting an irrigation system (either conventional or low-volume), is neither an art nor a science. Manual or automated drip/low-volume irrigation systems, like conventional sprinkler systems, consist of a series of separate but interconnected components. Troubleshooting is simply a series of tests which are performed to determine which component(s) are at fault by using a process of elimination.
Even a well-designed and properly installed irrigation system can eventually develop problems, and these problems are diverse and are not always caused by humans or mechanical failures. Growing roots for example, can move pipes and tubing, forcing them out of their fittings, which can cause leaks and breaks that can significantly increase the system’s flow rate, resulting in low dynamic pressure and poor system uniformity.
Conventional troubleshooting techniques can be employed to efficiently diagnose most common electrical and/or hydraulic problems with both high and low-volume systems—i.e., solenoid valves that fail to open or close, or clogged emission devices with reduced flow.
Drip and low-volume irrigation systems, however, operate at lower pressure, and contain two additional components not found on conventional sprinkler systems: a pressure regulator and an in-line filter, both of which may also require diagnosis.
There are several types of pressure regulators designed and manufactured for use with drip/low volume irrigation systems, and none of them will last forever. To verify that the regulator is still functioning, first make sure it is installed in the correct direction and location (after the filter and control valve) and that it has the correct flow range for the system it is installed on. Secondly, install a pressure gauge at the end of the line, open the system control valve, and check the system’s dynamic or operating pressure. On a relatively level system, under normal flow conditions, the pressure should be no higher than the pre-set limit on the regulator, and at least 10-15psi.
Efficient troubleshooting is a systematic process of elimination that requires keeping an open mind, not assuming anything. If the correct products are selected and the low-volume system is installed and maintained properly, problems will be minimal.
EDITOR’S NOTE: Stuart Spaulding, CLIA, Technical Service Manager for DIG Corporation.