When is a water column required to have a shield or sleeve?

A water column is required to have a shield or sleeve specifically when it is operated at pressures exceeding 400 psig. This requirement is in place to enhance safety and protect against potential hazards that arise at higher pressures, which can include the risk of leaks or ruptures.

The sleeve or shield serves to contain any potential spray of water or steam that could escape from the water column, thereby minimizing risks to personnel and equipment in the vicinity. Operating conditions beyond 400 psig introduce additional risks due to the increased energy contained within the system, and the shield provides a crucial layer of protection.

In lower pressure scenarios or when temperature is concerned, such as below 400 psig or at temperatures below 180°F, the same requirement for a shield does not apply as the risks associated with failure are considered lower, hence making the requirement for shielding unnecessary.