Under what conditions does hot water fall under regulatory code?

The correct choice indicates that hot water falls under regulatory code at a pressure of 30 psig and a temperature of 250 degrees Fahrenheit. This combination signifies that the water is not only under significant pressure but also at a high temperature, which together can create hazardous conditions if not properly managed. Regulatory codes are established to ensure safety and define thresholds for when systems, such as hot water systems, must adhere to specific standards and regulations.

At this pressure and temperature, the potential for accidents, such as steam formation or pipe failure, increases significantly, necessitating stringent controls and compliance with safety regulations. Systems operating above these thresholds are often required to have additional safety measures, inspections, and regulatory oversight to prevent accidents and ensure the safety of personnel and property.

While the other options present various combinations of pressure and temperature, they do not meet the specific regulatory standards that indicate when hot water systems must be regulated. This reinforces the importance of understanding both pressure and temperature in determining the applicability of safety codes in hot water applications.