Changes in Safety Valves for Hand-Fired Boilers

Purchasing new-style safety valves requires some knowledge of your old boiler.

Figure 1: The purpose of safety valves, in 1909 and today. A safety valve on a hand-fired boiler, as defined by ASME almost a hundred years ago, is to give notice of the highest pressure permissible and to give alarm that more water or less fuel is needed.
All figures courtesy of Bruce E. Babcock