Red Seal Gasfitter — Class B Practice Exam

The function of a manual shut-off valve in gas piping is to allow the user to cut off the gas supply. This is an essential safety feature in gas systems, providing a means for users or service personnel to stop the flow of gas during maintenance, emergencies, or repairs. The ability to manually shut off the gas is critical for preventing potential hazards such as leaks or fire, allowing for safe intervention when necessary.

Other options, while related to gas systems, do not accurately describe the core function of a manual shut-off valve. For instance, regulating gas pressure is typically the role of pressure regulators, not shut-off valves. Monitoring gas flow involves measurement devices that track the amount of gas moving through the system, which is distinct from the simple on/off capability of a shut-off valve. Gas leak detection is performed by specialized equipment designed to sense the presence of gas, which is not a function of a manual shut-off valve. Therefore, understanding the specific purpose of a manual shut-off valve focuses on its role in controlling the gas flow, ensuring safety and maintenance procedures can be conducted effectively.