It is necessary to re-set the relief valve every time you add an additional hose line.

It is necessary to re-set the relief valve every time you add an additional hose line.

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

Answer: (B)

Relief valves are safety devices that protect the pump and hose system from overpressure. They’re set to a fixed relief pressure for the system and aren’t normally adjusted every time you add another hose line. When you add more hose, you increase friction loss, which tends to lower the pressure at the nozzle rather than raise it. To maintain the desired discharge pressure, the operator adjusts the pump throttle or uses the governor, not by resetting the relief valve. You would only re-set the valve if you change the system’s maximum allowable pressure or after maintenance, not for routine hose additions. So this statement isn’t correct.

Relief valves are safety devices that protect the pump and hose system from overpressure. They’re set to a fixed relief pressure for the system and aren’t normally adjusted every time you add another hose line. When you add more hose, you increase friction loss, which tends to lower the pressure at the nozzle rather than raise it. To maintain the desired discharge pressure, the operator adjusts the pump throttle or uses the governor, not by resetting the relief valve. You would only re-set the valve if you change the system’s maximum allowable pressure or after maintenance, not for routine hose additions. So this statement isn’t correct.