The street steam PSI and TEMP is reduced by a PRV to 90-16 pounds, which is designed as what type of system?

A system designed to operate at a reduced pressure of 90-16 pounds is classified based on its maximum allowable working pressure (MAWP). In the context of high-pressure systems, pressure ratings dictate the classification.

A 125 psig system is characterized by its ability to handle steam pressures up to 125 psi safely. Since the reduced pressure of 90-16 pounds falls within the range of a 125 psig system's operational limits, the classification aligns with typical industrial equipment that is not expected to exceed that pressure.

The classification is crucial for safety and regulatory compliance, influencing the design, maintenance, and operation of steam systems. Thus, the appropriate designation of this system corresponds accurately to the 125 psig rating, making it the correct choice.