CSLB C-27 Landscaping ContractorIrrigation SystemsMedium
A landscape contractor is performing a winterization procedure on an irrigation system in a region prone to freezing temperatures. The system uses a master valve and multiple zone valves. After evacuating the water from the main lines and lateral lines using compressed air, what crucial step must be performed to prevent damage to the master valve?
- ALeave all zone valves in the 'open' position.
- BCompletely close the main water supply to the system.
- CApply antifreeze solution directly into the master valve.
- DEnsure the master valve is manually opened and blown out with air.
Show answer & explanationAnswer & explanation
Correct answer: D. Ensure the master valve is manually opened and blown out with air.
Even after blowing out the main and lateral lines, water can remain trapped within the master valve body, especially in areas like the solenoid or diaphragm chamber. Manually opening the master valve (either through the controller or by turning the solenoid a quarter turn) and then blowing air through it ensures that any remaining water is expelled, preventing freeze damage.
Why the other options are wrong
- A. Leaving zone valves open is correct for blowing out lateral lines, but doesn't specifically address the master valve itself.
- B. Closing the main water supply is a preliminary step, but doesn't ensure the master valve itself is clear of water.
- C. Antifreeze is not typically used for irrigation valves and could contaminate the system or potable supply.
Winterizing Master Valve
During irrigation system winterization, the master valve must be manually opened and blown out with compressed air to remove trapped water and prevent freeze damage.
- Water can get trapped in valve bodies, causing freeze damage.
- Master valves control water to all zones.
- Opening the valve allows air to clear remaining water.
Memory trick: Master valve, don't you freeze, open it up, blow with ease.