What safety practice should be observed when working with gas valves?

The appropriate safety practice when working with gas valves is to always ensure the valve is closed before maintenance. This is critical for preventing gas leaks, which can pose serious risks including fires, explosions, or exposure to harmful gases. By closing the valve, technicians create a safe working environment, reducing the hazard of gas escaping during maintenance tasks.

It's essential to approach any maintenance work on gas systems with the utmost caution. Ensuring that the valve is closed before starting work eliminates the possibility of inadvertently working on a live gas line. This practice not only protects the technician but also safeguards others in the vicinity from potential dangers.

In contrast, while wearing gloves might be advised for other maintenance tasks to protect against sharp edges or dirt, it does not specifically address the risks associated with gas. Ensuring the valve is open before maintenance would directly contradict safe practice, as it increases the risk of gas release. Using lubricants on all joints might be necessary in some situations, but not on gas valves specifically, as some lubricants can be incompatible with the gases or can contribute to leaks. Therefore, always closing the valve is a fundamental practice that underlies safe work when dealing with gas systems.