On boilers with more than 100 square feet of heating surface, what is the minimum size requirement for blow-down valves?

In the context of boilers with more than 100 square feet of heating surface, the minimum size requirement for blow-down valves being 1 inch is established based on safety and operational efficiency guidelines. The blow-down valves are crucial for removing sediment and other impurities that can accumulate in the boiler, ensuring efficient operation and prolonging the lifespan of the equipment.

A 1-inch blow-down valve provides sufficient flow for effective drainage while maintaining pressure integrity within the system. This size is considered adequate for managing the volume of water and steam that is expelled during the blow-down process, allowing operators to maintain proper water quality without risking damage to the boiler.

Larger sizes may provide more flow capacity, but the 1-inch requirement strikes a balance between effective operation and system design constraints. This choice reflects industry standards and practices that prioritize both safety and functionality in boiler operations.