MCC-NH Gas Fitters Practice Exam

What is required when the available supply pressure is higher than what the appliance is designed for?

1. A Pressure Relief Valve

2. A Pressure Reducing Valve

3. A Line Pressure Regulator

4. A Safety Shut-off Valve

The correct answer is: A Line Pressure Regulator

When the available supply pressure is higher than what the appliance is designed to handle, a Line Pressure Regulator is necessary to ensure that the gas pressure is reduced to a safe and acceptable level prior to reaching the appliance. This device regulates and maintains the gas pressure within the specified limits for the appliance to operate efficiently and safely. Using a Line Pressure Regulator allows the appliance to function correctly without being damaged by excess pressure, which could lead to hazards such as improper combustion or even potential failure of the equipment. In situations where supply pressure exceeds appliance specifications, it is crucial to implement a mechanism that can adjust the pressure to the required setting, thus preventing safety issues. The other options do serve important functions in gas systems, but they do not specifically address the need to reduce pressure to fit appliance specifications. A Pressure Relief Valve is designed to open and relieve pressure to prevent excessive pressure build-up, but it does not continuously regulate pressure to meet appliance needs. A Pressure Reducing Valve can also reduce pressure but typically refers to a type of valve used in different applications. A Safety Shut-off Valve serves to block gas flow under certain conditions but is not a mechanism for regulating pressure. Therefore, the most pertinent component for managing high supply pressure is the Line Pressure Regulator.