What minimum pressure must a boiler achieve before the pipe fittings should be at least schedule 80?

The requirement for using schedule 80 fittings in boiler systems is closely related to the pressures they are designed to withstand. Schedule 80 pipe fittings are thicker and have a higher pressure rating compared to schedule 40 or other lighter schedules. When a boiler operates at higher pressures, such as 100 psig, it is critical to use fittings that can safely handle the increased stress and potential for failure.

At 100 psig, the pressure within the system is substantial enough that the use of schedule 80 fittings is recommended to ensure safety and reliability. These fittings provide a greater tensile strength and resistance to deformation, which is essential in high-pressure environments where the risks associated with leaks or ruptures are significantly elevated.

Using a schedule that does not meet the necessary specifications for the operating pressure can result in catastrophic failures. Therefore, at 100 psig, the code and best practices dictate that schedule 80 fittings should be employed to mitigate risks and ensure the longevity and integrity of the piping system.