New York Low Pressure Boiler COF Practice

Under what circumstance is a bullseye water sight glass considered acceptable on a miniature boiler?

1. When it is a newer model

2. When there is insufficient space for a gage glass

3. When the boiler is larger than 500 kW

4. When the boiler is over 20 years old

The correct answer is: When there is insufficient space for a gage glass

A bullseye water sight glass is deemed acceptable on a miniature boiler primarily when there is insufficient space for a gage glass. This situation arises in environments where the installation context or the physical dimensions of the boiler prevent the standard installation of a conventional gage glass, which is typically used for more precise water level measurement. The bullseye sight glass provides a way to observe the water level inside the boiler, ensuring that operators can still monitor the water level for safe operation despite spatial constraints. It serves as a more compact alternative that can fit into tight areas while still providing the essential function of indicating water levels. While factors like the age of the boiler or its size (in kW) may influence the choice of sight glass type, they do not dictate whether a bullseye water sight glass is acceptable in the same way that the physical constraints of space do. Thus, the primary reason for its acceptance hinges on the necessity created by the lack of sufficient space for a traditional gage glass.