Where is the fusible plug for a 150-pound chlorine cylinder located?

The fusible plug for a 150-pound chlorine cylinder is located on the valve. This is important because the fusible plug is designed to melt at a specific temperature, allowing gas to escape safely in the event of a fire or excessive heat buildup. By being positioned at the valve, it helps prevent an explosion by enabling the release of chlorine gas when necessary. This safety feature ensures that pressure does not build up to dangerous levels within the cylinder, providing a controlled release mechanism for potentially hazardous gas.

Considering the other options, the top or side of the cylinder may seem plausible at first, but these locations would not effectively achieve the critical safety function of the fusible plug. The base of the cylinder is also not suitable, as positioning it there would not facilitate the immediate release of gas from the valve, thereby negating the safety purpose of the plug.