AWWA Equipment and Tools Knowledge 2 — Questions and Answers
Question 1: What is the primary function of a pressure reducing valve (PRV) in a water distribution system?
- Increase upstream pressure to distribution mains
- Reduce downstream pressure to a preset level (Correct answer)
- Measure flow rate through a pipeline
- Filter sediment from incoming water
Correct answer: Reduce downstream pressure to a preset level
A PRV automatically reduces higher inlet pressure to a lower, stable outlet pressure to protect downstream pipes and fixtures.
Question 2: Which type of valve is best suited for throttling flow in a water main?
- Gate valve
- Globe valve (Correct answer)
- Ball valve
- Check valve
Correct answer: Globe valve
Globe valves are designed for throttling because their disc can be precisely positioned to control flow rate.
Question 3: A turbine flow meter measures water flow by:
- Detecting pressure differential across an orifice plate
- Counting rotations of a spinning impeller in the flow stream (Correct answer)
- Measuring ultrasonic pulse transit time
- Detecting magnetic field changes in flowing water
Correct answer: Counting rotations of a spinning impeller in the flow stream
Turbine meters use a rotor that spins at a speed proportional to flow velocity, and rotation counts are converted to volume.
Question 4: What is the purpose of an air/vacuum relief valve installed at a high point in a pipeline?
- Release excess water pressure during surges
- Admit air during draining and expel air during filling (Correct answer)
- Regulate pressure in the distribution zone
- Sample water quality at elevated locations
Correct answer: Admit air during draining and expel air during filling
Air/vacuum relief valves open to let air in when the pipe drains (preventing vacuum collapse) and release trapped air when the pipe fills.
Question 5: Which pump type is most commonly used for high-flow, low-head water supply applications?
- Positive displacement pump
- Centrifugal pump (Correct answer)
- Peristaltic pump
- Diaphragm pump
Correct answer: Centrifugal pump
Centrifugal pumps excel at high-flow, low-to-moderate head conditions and are the dominant pump type in water utilities.
Question 6: A 'pig' used in pipeline operations is primarily used for:
- Pressure testing new main installations
- Cleaning and inspecting the interior of pipelines (Correct answer)
- Installing service taps on pressurized mains
- Flushing dead-end mains of stagnant water
Correct answer: Cleaning and inspecting the interior of pipelines
Pipeline pigs are devices propelled through pipes to clean, inspect, or separate fluids inside the pipeline.
Question 7: What does SCADA stand for in water utility operations?
- System Control and Data Acquisition
- Supervisory Control and Data Acquisition (Correct answer)
- Standardized Control and Distribution Automation
- Synchronized Communication and Data Analysis
Correct answer: Supervisory Control and Data Acquisition
SCADA (Supervisory Control and Data Acquisition) systems allow operators to remotely monitor and control water system equipment.
AWWA Equipment and Tools Knowledge 2
What is the primary function of a pressure reducing valve (PRV) in a water distribution system?