The main pump drain on the panel must not be opened or closed under pressure. Which of the following statements is true?

The main pump drain on the panel must not be opened or closed under pressure. Which of the following statements is true?

• A. True
• B. False
• C. Not applicable
• D. Unknown

Answer: (A)

Opening or closing the main pump drain while the pump is under pressure is dangerous and must not be done. The drain valve is designed to release water from the pump when you are not under pressure or when you are safely relieving residual pressure, but doing so while the system is pressurized can unleash a sudden jet of hot water, spray, or steam, posing scalding risks to firefighters and potentially causing hose or fitting damage from the shock of pressure (water hammer). In practice, you operate the drain only after you have shut the pump down and ensured the system is fully de-pressurized, or you vent/prime the pump with the pump off and the discharge lines isolated. This keeps you and the equipment safe while still allowing you to drain the pump when appropriate. Therefore, the statement is true.

Opening or closing the main pump drain while the pump is under pressure is dangerous and must not be done. The drain valve is designed to release water from the pump when you are not under pressure or when you are safely relieving residual pressure, but doing so while the system is pressurized can unleash a sudden jet of hot water, spray, or steam, posing scalding risks to firefighters and potentially causing hose or fitting damage from the shock of pressure (water hammer).

In practice, you operate the drain only after you have shut the pump down and ensured the system is fully de-pressurized, or you vent/prime the pump with the pump off and the discharge lines isolated. This keeps you and the equipment safe while still allowing you to drain the pump when appropriate. Therefore, the statement is true.