In a system with a single boiler, what type of steam boiler is exempt from the shutoff valve requirement?

In a system with a single boiler, low-pressure steam boilers are exempt from the shutoff valve requirement due to their operational parameters and associated safety considerations. Low-pressure steam systems typically operate at pressures below 15 psi, which generally presents a lower risk compared to higher-pressure systems. The rationale behind this exemption lies in the reduced potential for hazardous situations that could arise from leaks or failures in the system.

Higher-pressure systems, such as medium or high-pressure steam boilers, pose an increased risk of injury or damage due to their operation at elevated pressures. Consequently, the codes necessitate strict safety measures for these types, including the installation of shutoff valves to manage emergency situations effectively.

Water boilers also have distinct safety requirements, but the focus of the exemption pertains specifically to low-pressure steam boilers and their regulated standards under the mechanical code. Thus, the decision to exempt low-pressure steam boilers reflects an understanding of their lower operational hazards, leading to more streamlined requirements for their management and maintenance.