What device maintains low pressure in the gas supply to a gas furnace?

A pressure regulator is the device responsible for maintaining a low and consistent pressure in the gas supply to a gas furnace. Its main function is to reduce the pressure of the incoming gas from the supply line to a level that is suitable for the furnace's operation, ensuring safe and efficient combustion. By controlling and stabilizing the pressure, the regulator prevents fluctuations that could lead to inefficient functioning of the furnace or even dangerous conditions, such as gas leaks or explosions.

In HVAC systems, maintaining appropriate gas pressure is crucial because gas appliances are designed to operate within specific pressure ranges for optimal performance. If the pressure is too high, it can cause the furnace to overheat or damage components. Conversely, if the pressure is too low, the furnace may not ignite correctly or operate efficiently, leading to improper heating and increased energy costs.

Other devices like flow meters measure the amount of gas flowing but do not regulate pressure, while safety valves are designed to prevent excessive pressure from building up in the system but do not maintain low pressure during normal operation. The gas valve controls the flow of gas to the burner but does not ensure that the pressure is at the appropriate level. Thus, the pressure regulator is essential for safely managing the gas pressure in the furnace system.