At what pressure does a typical residential T/P relief valve operate?

The typical operating pressure for a residential temperature and pressure (T/P) relief valve is around 30 psi. T/P relief valves are crucial safety devices used in hot water heating systems to prevent excessive pressure buildup that could lead to dangerous situations, such as explosions.

Typically, these valves are calibrated to open at a pressure slightly above the normal operating pressure of the system to ensure safety. In most residential hot water systems, the maximum allowable working pressure is set to about 30 psi, so the T/P relief valve is designed to relieve at this pressure to protect the system from overpressure conditions.

The options represent pressures that are either too low or too high for the common operating conditions of residential hot water systems, making 30 psi the most appropriate choice for typical installations.