Filtration and Circulation Systems Flashcards
7 cards from real CPO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Filtration and Circulation Systems flashcards as text
Which type of valve is most commonly used to completely shut off flow in pool circulation piping?
Answer: Ball valve or gate valve
Ball valves and gate valves are both used to completely shut off flow in pool piping; ball valves are more common in modern installations due to their ease of operation.
What is the purpose of a hair and lint strainer (pump basket) in the circulation system?
Answer: To capture large debris before water reaches the pump impeller
The hair and lint strainer catches large debris such as hair, leaves, and lint before they can reach and damage the pump impeller.
A pool's flow rate is 200 GPM and the pool volume is 120,000 gallons. What is the turnover time?
Answer: Both B and C are correct
Turnover time = Volume ÷ Flow rate = 120,000 ÷ 200 GPM = 600 minutes = 10 hours; both answers B and C express the same result.
What is the minimum number of main drains required in new commercial pool construction to prevent suction entrapment?
Answer: Two drains separated by at least 3 feet
The Virginia Graeme Baker Pool & Spa Safety Act requires at least two main drains separated by a minimum of 3 feet to prevent dangerous suction entrapment.
Which filter type achieves the finest level of filtration, capable of removing particles as small as 1–3 microns?
Answer: Diatomaceous earth (DE) filter
DE filters can remove particles as small as 1–3 microns, which is finer than sand filters (20–40 microns) or cartridge filters (10–15 microns).
What condition is indicated when the suction pressure gauge on a pump reads a vacuum (negative pressure) higher than normal?
Answer: There is a blockage or restriction on the suction side of the pump
Excessive vacuum on the suction side indicates a restriction — such as a clogged strainer basket, closed valve, or blocked main drain — limiting water flow to the pump.
How is the flow rate of a pool circulation system most accurately measured in the field?
Answer: By using a flow meter installed in the return line
A flow meter installed in the return line provides the most accurate field measurement of actual water flow rate through the circulation system.