Which statement about the boiler desuperheater inlet valves is correct?

Which statement about the boiler desuperheater inlet valves is correct?

• A. They should be kept in Locked and open positions
• B. They should be kept closed
• C. They should be open only during testing
• D. They are not used in operation

Answer: (A)

Desuperheater inlet valves are treated as a flow path that must be reliably available when desuperheating is required. Keeping them locked in the open position ensures there is an immediate, unobstructed supply of water to the desuperheater whenever the control system calls for it, which is essential for maintaining the desired steam temperature. The lock prevents accidental or unwanted closing due to vibration, maintenance, or operator error, so the desuperheater can perform its cooling function without delay. The actual modulation of water flow is achieved downstream or through the control system, not by leaving the inlet valve partly closed. Leaving the valve closed or only opening it for testing would defeat the desuperheater’s purpose and risk overheating.

Desuperheater inlet valves are treated as a flow path that must be reliably available when desuperheating is required. Keeping them locked in the open position ensures there is an immediate, unobstructed supply of water to the desuperheater whenever the control system calls for it, which is essential for maintaining the desired steam temperature. The lock prevents accidental or unwanted closing due to vibration, maintenance, or operator error, so the desuperheater can perform its cooling function without delay. The actual modulation of water flow is achieved downstream or through the control system, not by leaving the inlet valve partly closed. Leaving the valve closed or only opening it for testing would defeat the desuperheater’s purpose and risk overheating.