For pipes joined together in a boiler operating at 100 psi MAWP, what methods are used?

In high-pressure boiler applications, such as one operating at 100 psi MAWP (Maximum Allowable Working Pressure), the integrity and strength of pipe joints are paramount. Flanged and welded connections are preferred methods because they can reliably withstand the stresses and pressures present in high-pressure environments.

Flanged joints involve the use of flat pieces of metal with holes that allow for the connection of two segments of piping. These flanges are bolted together, providing a secure and easily accessible means of assembly and disassembly, which is important for maintenance purposes. They effectively prevent leakage and can handle the thermal expansion and contraction of the materials under high pressure.

Welded joints, on the other hand, involve the fusion of the pipe materials themselves, creating a very strong and permanent bond. This method is particularly advantageous in high-pressure systems where leak prevention is critical, as welded joints are continuous without the potential gaps associated with other attachment methods. Welds become part of the piping, providing structural integrity that is crucial at elevated pressures.

Alternative methods such as screwed, bolted, clamped, glued, or soldered joints do not meet the required safety and strength standards typically employed for high-pressure boiler systems, as they are more susceptible to failure under high operational pressures.