According to ASME code, what is required for a boiler over 500 sq./ft. of heating surface?

In accordance with ASME code provisions, a boiler that has over 500 square feet of heating surface must be equipped with two safety valves. This requirement is put in place to enhance safety and reliability in the operation of larger boilers.

The rationale behind this requirement lies in the critical function of safety valves, which are designed to prevent excess pressure buildup within the boiler. In a scenario where one safety valve may fail or become inoperative, the second safety valve acts as a backup, ensuring that the boiler can still vent pressure effectively. This dual valve arrangement helps to mitigate risks associated with overpressure situations, which can lead to catastrophic failures, such as explosions.

For smaller boilers, a single safety valve might be deemed sufficient. However, as the potential for pressure-related hazards increases with larger heating surface areas, the code mandates the presence of an additional valve to safeguard against these risks. This requirement exemplifies the safety-first approach inherent in ASME standards, reflecting the importance of thorough risk management in boiler design and operation.