CIT - Certified Irrigation Technician Certified Irrigation Technician Hydraulics and Water Management 1

Question 1

A rectangular irrigation zone requires 1.5 inches of water per week. If the zone covers 8,000 square feet, what is the approximate weekly water volume needed (in gallons)?

Accepted Answer

4,990 gallons

Answer

7,480 gallons

Answer

9,960 gallons

Answer

14,960 gallons

Question 2

Which of the following conditions will cause water hammer to be most severe in an irrigation system?

Accepted Answer

Rapid valve closure with high flow velocity

Answer

Slow valve closure with low flow velocity

Answer

Gradual pressure increase with small pipe diameter

Answer

Low static pressure with high pipe elevation

Question 3

A flow meter on an irrigation mainline reads 28 GPM when supplying a zone. The mainline pipe has an internal diameter of 1.5 inches. What is the approximate flow velocity in that pipe?

Accepted Answer

7.9 ft/s

Answer

3.1 ft/s

Answer

5.4 ft/s

Answer

10.2 ft/s

Question 4

An irrigation designer needs to select between two pipe sizes for a lateral line: 3/4-inch and 1-inch. The 1-inch pipe has approximately how many times more flow capacity than the 3/4-inch pipe, assuming the same friction loss?

Accepted Answer

1.8 times more

Answer

1.3 times more

Answer

2.4 times more

Answer

3.2 times more

Question 5

A drip irrigation system operates at 20 PSI at the emitter inlet. The manufacturer's rated flow at 15 PSI is 0.5 GPH per emitter. Using the square root relationship for pressure-compensating emitters (non-compensating), what is the approximate flow rate at 20 PSI?

Accepted Answer

0.58 GPH

Answer

0.50 GPH

Answer

0.65 GPH

Answer

0.71 GPH

Question 6

A technician is sizing a pump for an irrigation system that must overcome 35 PSI of static pressure, 12 PSI of friction loss in the mainline, and supply heads with a minimum operating pressure of 30 PSI. What is the minimum total dynamic head (TDH) the pump must produce, expressed in PSI?

Accepted Answer

77 PSI

Answer

42 PSI

Answer

53 PSI

Answer

65 PSI