CIT - Certified Irrigation Technician Irrigation Principles and Components Questions and Answers — Questions and Answers
Question 1: An irrigation technician measures the water pressure at a hose bibb before the system is turned on and gets a reading of 65 PSI. After the zone with the highest flow is activated, the pressure is measured again at the same point and reads 50 PSI. What is the 50 PSI reading called?
- Friction loss
- Static pressure
- Dynamic pressure (Correct answer)
- Surge pressure
Correct answer: Dynamic pressure
Dynamic pressure, also known as working or operating pressure, is the pressure of water when it is in motion. Static pressure is the water pressure when the water is at rest. The difference between the static and dynamic pressure in this scenario is due to friction loss, but the measurement itself is dynamic pressure.
Question 2: A client's irrigation system is causing a fine mist to come from the spray heads, leading to poor water distribution and significant waste from wind drift. Which of the following is the MOST likely cause of this issue?
- Low water pressure
- High water pressure (Correct answer)
- Clogged sprinkler nozzles
- A partially closed master valve
Correct answer: High water pressure
High water pressure is a common cause of misting or fogging from spray heads. This occurs when the pressure exceeds the manufacturer's recommended operating range, causing the water to atomize. Low pressure would result in a weak spray and reduced radius, while clogged nozzles would typically create an irregular or blocked pattern.
Question 3: What is the primary function of a backflow prevention device in an irrigation system?
- To increase water pressure for better sprinkler coverage.
- To filter out debris and sediment from the water supply.
- To prevent contamination of the potable water supply. (Correct answer)
- To regulate the flow rate to individual irrigation zones.
Correct answer: To prevent contamination of the potable water supply.
The primary and legally required function of a backflow preventer is to protect the potable (drinking) water supply from contamination. It ensures that water from the irrigation system, which could contain fertilizers, pesticides, or other contaminants, cannot flow backward into the clean water source due to changes in pressure like back-siphonage or back-pressure.
Question 4: A technician needs to calculate the precipitation rate for a sprinkler zone to program the controller correctly. Which formula is commonly used for this calculation?
- PR = (Area x 96.3) / GPM
- PR = (GPM x Area) / 96.3
- PR = GPM / (Area x 96.3)
- PR = (GPM x 96.3) / Area (Correct answer)
Correct answer: PR = (GPM x 96.3) / Area
The standard formula to calculate the precipitation rate (PR) in inches per hour is: PR = (Total Gallons Per Minute of all heads in the zone x 96.3) / Total Area of the zone in square feet. The constant 96.3 is a conversion factor that simplifies the calculation from gallons per minute over a square footage area into inches per hour.
Question 5: While performing system maintenance, a technician notices that one entire zone of rotor heads is not operating, while all other zones function correctly. The controller indicates the zone is active. Which of the following is the LEAST likely cause of this specific problem?
- A faulty zone valve solenoid
- A cut in the field wiring to that specific zone
- A broken mainline pipe before the zone valve (Correct answer)
- A malfunctioning diaphragm in the zone valve
Correct answer: A broken mainline pipe before the zone valve
A broken mainline pipe would affect all zones downstream from the break, or cause a constant leak, rather than isolating the problem to a single zone that won't turn on. A faulty solenoid, a cut in the specific zone wire, or a malfunctioning valve diaphragm are all common electrical or mechanical failures that would prevent a single, specific zone from operating.
Question 6: Which of the following components is essential for connecting a sprinkler head to a lateral line while providing flexibility and protection against damage from mowers or foot traffic?
- Reducer bushing
- Swing joint assembly (Correct answer)
- Gate valve
- Pressure regulator
Correct answer: Swing joint assembly
A swing joint assembly, which consists of articulated fittings, is used to connect a sprinkler head to the lateral pipe. Its primary purposes are to allow for precise height and position adjustment of the sprinkler head and to provide flexibility, which helps protect both the sprinkler and the pipe from damage if the head is hit.
CIT - Certified Irrigation Technician Irrigation Principles and Components Questions and Answers
An irrigation technician measures the water pressure at a hose bibb before the system is turned on and gets a reading of 65 PSI.
After the zone with the highest flow is activated, the pressure is measured again at the same point and reads 50 PSI.
What is the 50 PSI reading called?