Texas Irrigator License Exam 2020:
Backflow Questions with Correct
Answers
Air Gap - ANSWERSGap through air between lowest point of water supply & flood level
rim.
i.e. Sink water level & faucet
Anti-Siphon Device - ANSWERSAny device that introduces air into the system to
prevent back siphonage.
AVB (Atmospheric Vacuum Breaker) or PVB (Pressure-type Vacuum Breaker)
Atmospheric Vacuum Breaker (AVB) - ANSWERSBlackflow device that allows air with
use of a float.
Shape: Like an L
Back Pressure: No
Constant Pressure: No more than 12 hrs in 24-hr period.
Install Height: Vertically with min of 6" higher than all downstream piping and highest
downstream head.
Install: No shut-off valves downstream. Must be on discharge side of each control valve.
Backflow - ANSWERSUnwanted reversal of water flow
Backpressure - ANSWERSWhere pressure in the discharge (outlet or downstream) side
is greater than pressure in the supply (inlet or upstream) side.
i.e. Gravity from elevation, pump, steam/air pressure.
Backsiphonage - ANSWERSBackflow from negative pressure in the system.
i.e Break in city main line or fire department using excessive amount of water.
Types of Backflow Preventors - ANSWERSAir Gap
Backflow Questions with Correct
Answers
Air Gap - ANSWERSGap through air between lowest point of water supply & flood level
rim.
i.e. Sink water level & faucet
Anti-Siphon Device - ANSWERSAny device that introduces air into the system to
prevent back siphonage.
AVB (Atmospheric Vacuum Breaker) or PVB (Pressure-type Vacuum Breaker)
Atmospheric Vacuum Breaker (AVB) - ANSWERSBlackflow device that allows air with
use of a float.
Shape: Like an L
Back Pressure: No
Constant Pressure: No more than 12 hrs in 24-hr period.
Install Height: Vertically with min of 6" higher than all downstream piping and highest
downstream head.
Install: No shut-off valves downstream. Must be on discharge side of each control valve.
Backflow - ANSWERSUnwanted reversal of water flow
Backpressure - ANSWERSWhere pressure in the discharge (outlet or downstream) side
is greater than pressure in the supply (inlet or upstream) side.
i.e. Gravity from elevation, pump, steam/air pressure.
Backsiphonage - ANSWERSBackflow from negative pressure in the system.
i.e Break in city main line or fire department using excessive amount of water.
Types of Backflow Preventors - ANSWERSAir Gap
