New York Low Pressure Boiler COF Practice

What is the maximum pressure range allowed on a gauge when using a magnitude of 5 psig?

1. 5 psig

2. 10 psig

3. 15 psig

4. 20 psig

The correct answer is: 10 psig

The correct answer reflects the maximum pressure range that is permissible when measuring a magnitude of 5 psig. In the context of low-pressure boilers, the gauge typically allows for a range that is higher than the actual operating pressure to ensure accurate readings without risking damage to the gauge itself. A gauge with a maximum range of 10 psig can safely accommodate a pressure of 5 psig, as it provides a margin that ensures the pointer does not reach the maximum limit of the gauge, which could lead to inaccuracies or potential failure of the instrument. This range also allows for any minor fluctuations in pressure during regular operation. Higher gauge capacities, such as 15 psig or 20 psig, would also technically provide room for 5 psig but are not the most economical or efficient choice for precision instrumentation purposes. A gauge with a range much higher than the expected operation may yield less sensitive readings, which could make monitoring less effective, particularly in a low-pressure system. Therefore, a 10 psig gauge is the most suitable for maintaining accuracy while adequately covering the 5 psig operational level.