ASME Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

In the context of boilers and their safety systems, the maximum allowable working pressure (MAWP) is a critical parameter that indicates the maximum pressure under which the boiler can operate safely. When safety valves are installed, they serve as crucial protective devices designed to prevent overpressure by releasing steam or fluid when the internal pressure exceeds a predetermined level.

The correct answer relates to the operational threshold of these safety mechanisms. When safety valves are performing as designed, the pressure within the boiler can safely rise slightly above the MAWP, typically up to a limit of 106% of the MAWP. This allowance is provided to account for potential fluctuations in pressure during normal operations. Operating at this level ensures that the system remains safe while allowing for some operational flexibility.

Understanding why 106% of MAWP is acceptable involves recognizing the engineering design principles and safety considerations inherent in boiler systems. The design takes into account various factors such as temperature variations, fluid dynamics, and mechanical wear over time, ensuring that even with a slight increase in pressure, the structural integrity and safety of the boiler are not compromised.

In contrast, the other options present operational limits that exceed the recommended safety parameters. For instance, exceeding 120% of the MAWP introduces significant risk, as it could lead