shutoff

Shutoff refers to the act or device used to stop the flow of a substance or energy from a supply. It is commonly used in utilities such as electricity, gas, and water, as well as in industrial equipment, to prevent damage, manage usage, and ensure safety.

An electrical shutoff refers to equipment that disconnects power, including main service disconnects, circuit breakers, and fuses. Many systems also employ emergency stop devices on machinery, which instantly halt operation in an emergency.

Gas shutoffs include main shutoff valves near the meter and individual appliance shutoffs. Water shutoffs include the main house valve and various isolation valves on pipes and appliances. Valves used to shut off flow include ball valves, gate valves, and globe valves; automatic shutoff valves exist in gas detection and fire-suppression systems.

Shutoffs can be operated manually or automatically. Manual shutoffs require turning a handle or lever; automatic shutoffs react to sensors, timers, or control systems to stop flow without human intervention.

Safety and regulatory considerations emphasize accessibility, clear labeling, and regular maintenance. Codes in many regions require readily accessible shutoffs for gas and electricity and mandate testing or inspection at intervals. Properly functioning shutoff provisions help prevent leaks, flooding, fire risk, and equipment damage.