A line pressure regulator should be installed when the appliance operates at a pressure that is what in relation to the supply pressure?

A line pressure regulator is designed to reduce the supply gas pressure to a level that is suitable for the operation of an appliance. When the appliance requires a lower pressure than what is supplied from the main gas line, a pressure regulator is necessary to ensure that the appliance receives a stable and appropriate pressure for efficient and safe operation. If the appliance operates at a pressure that is lower than the supply pressure, the regulator will effectively lower this pressure to meet the appliance's specifications.

In systems where the supply pressure is higher than what the appliance is rated for, using a regulator is essential to avoid potential damage to the appliance or unsafe operating conditions. The regulator functions by controlling the gas flow and maintaining a consistent outlet pressure, which is crucial for performance and safety.

Understanding this relationship between supply pressure and appliance operating pressure is fundamental for ensuring that gas-powered appliances function reliably and safely within their designed parameters.