What is the minimum size of a gage glass cleaning hole?

The minimum size of a gage glass cleaning hole being 1/4 inch is appropriate because it allows adequate access for cleaning the gage glass, which is essential for ensuring accurate readings and maintaining safety. Gage glasses serve a crucial role in indicating the water level in a boiler, and any obstructions or deposits can compromise their functionality. A cleaning hole of this size provides enough clearance for tools or cleaning agents to effectively remove buildup or contaminants that could affect the clarity of the glass, thus ensuring that operators can accurately monitor the water level.

Larger sizes could also be used, but it's important that the opening be large enough to facilitate effective maintenance without becoming unnecessarily large, which might introduce structural concerns or allow for greater risk of leaks. Choosing 1/4 inch strikes a balance between functionality and practicality in boiler operation.