The _________ of a pilot-operated relief valve can be used to change the pressure setting of a relief valve from a remote location.

The _________ of a pilot-operated relief valve can be used to change the pressure setting of a relief valve from a remote location.

• A. Spool
• B. Vent port
• C. Spring
• D. Poppet

Answer: (B)

The important idea is how a pilot‑operated relief valve uses a pilot signal to control when the main valve opens. The vent port provides the path for a remote pressure signal to reach the pilot chamber. By feeding a signal pressure into this port, you change the pilot pressure, which shifts the balance that keeps the main valve closed and thus changes the pressure at which the valve starts to relieve. In other words, the vent port lets you tune the setpoint from a distant location without manually adjusting the valve itself. The other parts—spool, spring, and poppet—are components of the valve mechanism that determine how the valve opens and seals, but they don’t provide a means for remote setting.

The important idea is how a pilot‑operated relief valve uses a pilot signal to control when the main valve opens. The vent port provides the path for a remote pressure signal to reach the pilot chamber. By feeding a signal pressure into this port, you change the pilot pressure, which shifts the balance that keeps the main valve closed and thus changes the pressure at which the valve starts to relieve. In other words, the vent port lets you tune the setpoint from a distant location without manually adjusting the valve itself. The other parts—spool, spring, and poppet—are components of the valve mechanism that determine how the valve opens and seals, but they don’t provide a means for remote setting.