TEXAS IRRIGATION STUDY GUIDE 2025/2026 QUESTIONS
AND ANSWERS RATED A+
✔✔Distribution Uniformity - ✔✔The uniformity of the distribution of water over a given
irrigated area. It is calculated using a catchment test. Divide the average reading of the
driest 25% of catch cans by the average reading of all the catchments, and then multiply
by 100. Closer to 100% is better.
✔✔Double Check Valve Assembly - ✔✔Backflow prevention assembly, using two shut-
off valves and to check valves assembled and pre-tested at the factory, designed to
physically block or prevent backflow.
✔✔Drip Irrigation - ✔✔The slow application of water to the specific root zone of the
plant material using very low pressure. Expressed in gallons per hour.
✔✔Dry Line Shock - ✔✔The shock which occurs when a valve is opened and the water
travels unrestricted in empty piping. This happens when the water is turned on too fast
and the air can damage the pipes.
✔✔Dynamic Water - ✔✔Water that is in motion through the system as known as
working pressure.
✔✔Electrolysis - ✔✔The chemical reaction when two dissimilar metals are connected.
This reaction results in the deterioration of the piping.
✔✔Emitters - ✔✔A small mechanical device used in drip irrigation to limit water flow to a
drip or slow trickle.
✔✔Evapotranspiration - ✔✔The combination of water that has evaporated from the soil
and transpired from the plant material. This is the measurement of total amount of water
needed for plants to grow.
✔✔FPS - ✔✔Feet per second
✔✔Friction Loss - ✔✔Pressure loss due to friction as water flows through all
components of a system. The rougher the inside of the pipe or component, the more
friction loss is encountered.
✔✔Gauge (in reference to wire sizing) - ✔✔Standards used for wire sizing. The larger
the gauge number, the smaller the wire diameter.
✔✔GPH - ✔✔Gallons Per Hour
✔✔GPM - ✔✔Gallons Per Minute
, ✔✔Degree of Hazard - ✔✔a measure of the degree of risk or harm to the public's
health. Possible hazards are on site sewage & fertilizer injectors.
✔✔Head to Head Spacing - ✔✔Spacing of heads that is equal to the published radius
of the head. Equal to 50% of the diameter of the head.
✔✔Hydrozone - ✔✔An irrigation area of plant material with similar watering
requirements
✔✔Isolation Valve - ✔✔generally a gate or ball valve serves as a main shut-off device
for the complete irrigation system as needed for servicing or repair
✔✔Lateral Piping - ✔✔Piping between the remote control valve, not subject to constant
main line pressure, and the sprinkler heads
✔✔Main Line - ✔✔Located between the back flow and the remote control valves.
*always has pressure*
✔✔Master Valve - ✔✔automatic valve installed at the supply point which controls water
flow into the system main line piping
✔✔Matched Precipitation (MPR) - ✔✔all sprinkler heads within a watering zone will
produce similar precipitation rates, regardless of the pattern they cover
✔✔Non-Potable Water - ✔✔Water not suitable for human consumption
✔✔Nozzle Tree - ✔✔interchangeable nozzle assortment, with different GPM, provided
with many rotary heads
✔✔POC- Point of Connection - ✔✔Where a connection is made on the service line
✔✔Polyethylene Pipe - ✔✔flexible plastic pipe which uses insert fittings
✔✔Pressure Compensating - ✔✔maintaining a constant discharge pressure regardless
of inlet pressure.
✔✔Pressure Regulator - ✔✔A mechanical device that lowers the water pressure on the
downstream side of the unit
✔✔PVC Pipe - ✔✔Poly Vinyl Chloride Pipe
✔✔Types of Sensors - ✔✔Rain, Freeze, Wind, and Soil Moisture (Rain is mandatory on
new systems)
AND ANSWERS RATED A+
✔✔Distribution Uniformity - ✔✔The uniformity of the distribution of water over a given
irrigated area. It is calculated using a catchment test. Divide the average reading of the
driest 25% of catch cans by the average reading of all the catchments, and then multiply
by 100. Closer to 100% is better.
✔✔Double Check Valve Assembly - ✔✔Backflow prevention assembly, using two shut-
off valves and to check valves assembled and pre-tested at the factory, designed to
physically block or prevent backflow.
✔✔Drip Irrigation - ✔✔The slow application of water to the specific root zone of the
plant material using very low pressure. Expressed in gallons per hour.
✔✔Dry Line Shock - ✔✔The shock which occurs when a valve is opened and the water
travels unrestricted in empty piping. This happens when the water is turned on too fast
and the air can damage the pipes.
✔✔Dynamic Water - ✔✔Water that is in motion through the system as known as
working pressure.
✔✔Electrolysis - ✔✔The chemical reaction when two dissimilar metals are connected.
This reaction results in the deterioration of the piping.
✔✔Emitters - ✔✔A small mechanical device used in drip irrigation to limit water flow to a
drip or slow trickle.
✔✔Evapotranspiration - ✔✔The combination of water that has evaporated from the soil
and transpired from the plant material. This is the measurement of total amount of water
needed for plants to grow.
✔✔FPS - ✔✔Feet per second
✔✔Friction Loss - ✔✔Pressure loss due to friction as water flows through all
components of a system. The rougher the inside of the pipe or component, the more
friction loss is encountered.
✔✔Gauge (in reference to wire sizing) - ✔✔Standards used for wire sizing. The larger
the gauge number, the smaller the wire diameter.
✔✔GPH - ✔✔Gallons Per Hour
✔✔GPM - ✔✔Gallons Per Minute
, ✔✔Degree of Hazard - ✔✔a measure of the degree of risk or harm to the public's
health. Possible hazards are on site sewage & fertilizer injectors.
✔✔Head to Head Spacing - ✔✔Spacing of heads that is equal to the published radius
of the head. Equal to 50% of the diameter of the head.
✔✔Hydrozone - ✔✔An irrigation area of plant material with similar watering
requirements
✔✔Isolation Valve - ✔✔generally a gate or ball valve serves as a main shut-off device
for the complete irrigation system as needed for servicing or repair
✔✔Lateral Piping - ✔✔Piping between the remote control valve, not subject to constant
main line pressure, and the sprinkler heads
✔✔Main Line - ✔✔Located between the back flow and the remote control valves.
*always has pressure*
✔✔Master Valve - ✔✔automatic valve installed at the supply point which controls water
flow into the system main line piping
✔✔Matched Precipitation (MPR) - ✔✔all sprinkler heads within a watering zone will
produce similar precipitation rates, regardless of the pattern they cover
✔✔Non-Potable Water - ✔✔Water not suitable for human consumption
✔✔Nozzle Tree - ✔✔interchangeable nozzle assortment, with different GPM, provided
with many rotary heads
✔✔POC- Point of Connection - ✔✔Where a connection is made on the service line
✔✔Polyethylene Pipe - ✔✔flexible plastic pipe which uses insert fittings
✔✔Pressure Compensating - ✔✔maintaining a constant discharge pressure regardless
of inlet pressure.
✔✔Pressure Regulator - ✔✔A mechanical device that lowers the water pressure on the
downstream side of the unit
✔✔PVC Pipe - ✔✔Poly Vinyl Chloride Pipe
✔✔Types of Sensors - ✔✔Rain, Freeze, Wind, and Soil Moisture (Rain is mandatory on
new systems)
