When both intermittent blowoff valves on a boiler are seatless, which valve should be opened first?

When dealing with intermittent blowoff valves on a boiler, it is crucial to understand fluid dynamics and the potential for pressure fluctuations. The correct practice is to open the valve furthest from the boiler first and close it last. This method ensures that the flow of water or steam is directed in a controlled manner, reducing the risk of turbulence or sudden pressure changes that can occur if the nearest valve is opened first.

By opening the valve furthest from the boiler, the pressure in the system is gradually released over a larger distance, allowing for more effective venting of residual pressures or contaminants without causing a sudden surge. If the closer valve were opened first, it could lead to rapid changes in pressure in the immediate vicinity of the boiler, potentially causing issues such as water hammer or other disturbances in the boiler system.

Closing the furthest valve last serves the same purpose; it maintains a steady flow and allows for a controlled release of pressure back towards the boiler, protecting the integrity of the system throughout the blowoff process. This practice is standard in boiler operations to ensure safety and efficiency.