Which type of valve is specifically noted as needing to be locked and sealed open if used between a boiler and water column?

A shut-off valve is specifically noted as needing to be locked and sealed open when installed in a piping system between a boiler and a water column because it plays a crucial role in ensuring safe operation. The purpose of this requirement is to prevent the valve from inadvertently closing, which could lead to dangerous pressure fluctuations, system failures, or even catastrophic events such as boiler explosions.

In many applications, particularly those involving boilers, the flow of water or steam is critical for proper operation. A shut-off valve, if it were to close unexpectedly, could isolate part of the system and cause serious harm. By locking and sealing the shut-off valve in the open position, you ensure that fluid flow is maintained at all times, providing a more reliable and safe operation.

This locking and sealing requirement contributes to creating a safe working environment and adherence to regulatory standards that govern boiler operations. Proper understanding of this safety measure is essential for any journeyman pipefitter engaged in boiler installation, maintenance, and operation.