What is the minimum thickness for boiler blow-off fittings when the boiler pressure exceeds 100 psig?

The minimum thickness for boiler blow-off fittings required when the boiler pressure exceeds 100 psig is based on the need for strength and safety under high pressure conditions. Schedule 80 pipe thickness is specifically designed to handle higher pressures, making it suitable for this application. The thicker walls of Schedule 80 provide greater resistance to the stresses caused by high internal pressure, reducing the risk of failures such as ruptures or leaks.

In applications involving boilers under such high pressure, it is important to adhere to codes and standards that ensure the integrity of the system. The use of Schedule 80 fittings supports the structural integrity necessary to safely manage the pressures associated with heated water or steam in a boiler.

The other schedules, while they may be used for various applications, do not meet the required thickness for systems where pressures exceed 100 psig. For instance, Schedule 40 may not provide sufficient thickness; while Schedule 60 may be more robust than necessary, Schedule 80 is the minimum standard that adequately meets the requirements established in codes for high-pressure boiler applications.