For appliances designed to operate with a gas supply pressure of 14 in. w.c. or less, what should each overpressure protection device be adjusted to limit the gas pressure to?

Appliances that are designed to operate at a gas supply pressure of 14 inches of water column (w.c.) or less require overpressure protection devices to ensure that the gas pressure does not exceed safe operating limits. These devices are crucial for preventing damage to the appliance and reducing the risk of hazardous situations, such as gas leaks or fires.

The correct adjustment for these overpressure protection devices is to limit the gas pressure to 2 PSI. This limit is established to ensure that even in the case of a malfunction or fluctuation in the gas supply, the pressure remains within a safe range that is suitable for appliances operating at low pressure. Maintaining a maximum pressure of 2 PSI provides a significant safety margin above the typical operating pressure, while still being low enough to not affect the performance or safety of the appliances designed for low-pressure operation.

This safety standard is part of the regulatory framework that governs gas appliance installations and helps protect consumers by minimizing risks associated with overpressure conditions. Other options like 3 PSI, 4 PSI, or 5 PSI exceed the safe operating pressure for these specific appliances, which could lead to operational issues or hazards.