- Certified Irrigation Technician System Maintenance and Repair Flashcards

A sprinkler head is not retracting fully after the zone turns off. The most likely cause is:

Answer: Dirt, debris, or a worn spring in the sprinkler body preventing the riser from retracting

A sprinkler head that doesn't retract properly usually has dirt or debris between the riser and the body, or the internal spring that forces the riser down has weakened or broken. Cleaning the head and replacing the spring (or the entire head) resolves the issue.

During a spring startup of an irrigation system that was winterized by blowout, the technician should:

Answer: Slowly open the main water supply, allowing pipes to fill gradually, then test each zone individually for leaks and proper operation

Spring startup requires gradually filling the system with water to prevent water hammer and allow the technician to identify any damage from freezing, settling, or other winter events. Each zone should be tested individually for leaks, head alignment, and proper operation.

A zone valve is stuck open (water continues flowing even when the controller turns off the zone). What should the technician check first?

Answer: The solenoid, diaphragm, and bleed port for debris or damage

A valve stuck open is typically caused by debris in the diaphragm or bleed port, a torn diaphragm, or a solenoid that isn't seating properly. These components control the valve's closing mechanism and are the first items to inspect.

What is the correct method for winterizing an irrigation system by compressed air blowout?

Answer: Connect a compressor (limited to 50 PSI for PE/PVC) to the mainline after the backflow preventer and blow out each zone sequentially, starting from the farthest zone

Winterization by blowout uses compressed air to push water from all pipes, valves, and heads. Air pressure must be limited (50 PSI for PE/PVC, 80 PSI for copper) to prevent pipe and fitting damage. Each zone is blown out individually until no water is visible from the heads.

A rotor sprinkler head is turning but the radius has decreased significantly from its original design. The most likely cause is:

Answer: Low water pressure, a worn or clogged nozzle, or debris in the filter screen

Reduced throw radius in a rotor is typically caused by low operating pressure (often from a system leak elsewhere), a nozzle that has worn to a larger orifice (reducing pressure), a clogged nozzle, or a dirty filter screen restricting flow to the head.

When replacing a broken sprinkler head, the technician notices the replacement head sits 2 inches above grade after installation. The correct action is to:

Answer: Cut and lower the swing joint or riser to bring the top of the head flush with grade

Sprinkler heads must be installed flush with the surrounding grade. A head sitting above grade is vulnerable to mower damage, is a trip hazard, and looks unprofessional. The technician should adjust the swing joint depth or cut the riser to bring the head to the correct level.