Final answer:
A service shut-off valve should only be closed using the correct tool, like a valve key or wrench, to prevent damage to the valve and plumbing system. For safety, the correct operation should be learned, and caution is necessary especially with gas valves to avoid dangerous leaks.
Step-by-step explanation:
A service shut-off valve should only be closed with the specific tool designed for that valve, such as a valve key or wrench. It is important to use the correct tool to ensure that you do not damage the valve, which could lead to leaks or other issues. Moreover, closing a valve too quickly could cause water hammer, a surge of pressure that can damage the plumbing system. When dealing with gas valves, extra caution must be taken to prevent gas leaks, which can be very dangerous.
Before working with any shut-off valves, it is critical to know their location and operation procedure in case of an emergency. Always refer to the manuals provided by the manufacturer or consult with a professional. If uncertain, do not attempt to operate service shut-off valves without proper guidance.