Texas Irrigator License Exam 2024/25: Hydraulics
Questions and Answers
Distribution Uniformity (DU) CORRECT ANS-Uniformity of distribution of water over a
given area as a %.
Found by doing a catch can test.
Closer to 100% is better with 75%-80% excellent, 65%-75% good and <65% poor.
Dynamic Water CORRECT ANS-Water in motion
Dynamic Pressure (Working Pressure) CORRECT ANS-Pressure of water in motion.
Pressure left wehn all pressure losses are subtracted from static pressure.
Elevation Gain & Loss CORRECT ANS-Pressure gain or loss of 0.433 psi for each 1' of
elevation.
Flow CORRECT ANS-Movement of water in pipes. Measured as gpm (gallons per minute).
Causes friction loss
Flow Restrictions CORRECT ANS-Physical restrictions in parts of an irrigation system that
affect the flow of water causing a pressure loss.
Foot-Head CORRECT ANS-Measure of pressure equivalent to 0.433 psi and equal to weight
of 1' of water on a 1 sq in surface.
, Texas Irrigator License Exam 2024/25: Hydraulics
Questions and Answers
FPS CORRECT ANS-Feet per second
Maintained through size. Think of it like traffic. As velocity increased flow increases.
Copper is 9 fps. Brass 7.5 fps. PVC 5 fps.
Friction Loss CORRECT ANS-Pressure loss due to friction as water flows through parts.
Rougher means more friction loss.
Hydraulics CORRECT ANS-1. Study of mechanical properties of fluid in motion or rest.
2. Calculation of pressure losses & irrigation system requirements.
Matched Precipitation Rate (MPR) CORRECT ANS-When all heads in a zone produce similar
precipitation rates regardless of their arc.
i.e. With MPR, a 4 gpm full nozzle will put out 2 gpm on a half nozzle and 1 gpm on a quarter
nozzle. Each quarter section receives the same precipitation rate of 1 gpm.
Pressure CORRECT ANS-Amount of energy available to move water. Expressed as Pounds
per Square Inch (PSI).
Pressure Loss CORRECT ANS-Loss of pressure from friction or increase of elevation.
Hydraulic Design Steps CORRECT ANS-1. Layout heads
2. Head inventory
Questions and Answers
Distribution Uniformity (DU) CORRECT ANS-Uniformity of distribution of water over a
given area as a %.
Found by doing a catch can test.
Closer to 100% is better with 75%-80% excellent, 65%-75% good and <65% poor.
Dynamic Water CORRECT ANS-Water in motion
Dynamic Pressure (Working Pressure) CORRECT ANS-Pressure of water in motion.
Pressure left wehn all pressure losses are subtracted from static pressure.
Elevation Gain & Loss CORRECT ANS-Pressure gain or loss of 0.433 psi for each 1' of
elevation.
Flow CORRECT ANS-Movement of water in pipes. Measured as gpm (gallons per minute).
Causes friction loss
Flow Restrictions CORRECT ANS-Physical restrictions in parts of an irrigation system that
affect the flow of water causing a pressure loss.
Foot-Head CORRECT ANS-Measure of pressure equivalent to 0.433 psi and equal to weight
of 1' of water on a 1 sq in surface.
, Texas Irrigator License Exam 2024/25: Hydraulics
Questions and Answers
FPS CORRECT ANS-Feet per second
Maintained through size. Think of it like traffic. As velocity increased flow increases.
Copper is 9 fps. Brass 7.5 fps. PVC 5 fps.
Friction Loss CORRECT ANS-Pressure loss due to friction as water flows through parts.
Rougher means more friction loss.
Hydraulics CORRECT ANS-1. Study of mechanical properties of fluid in motion or rest.
2. Calculation of pressure losses & irrigation system requirements.
Matched Precipitation Rate (MPR) CORRECT ANS-When all heads in a zone produce similar
precipitation rates regardless of their arc.
i.e. With MPR, a 4 gpm full nozzle will put out 2 gpm on a half nozzle and 1 gpm on a quarter
nozzle. Each quarter section receives the same precipitation rate of 1 gpm.
Pressure CORRECT ANS-Amount of energy available to move water. Expressed as Pounds
per Square Inch (PSI).
Pressure Loss CORRECT ANS-Loss of pressure from friction or increase of elevation.
Hydraulic Design Steps CORRECT ANS-1. Layout heads
2. Head inventory
