Preventers

Preventers are devices or systems designed to prevent or reduce the likelihood and consequences of hazardous or unwanted events. They are used across industries to restrain motion, seal pressures, block access, or otherwise interrupt a process before damage occurs. They may be passive components, such as mechanical stops, or active systems that detect fault conditions and respond automatically.

In sailing, a preventer is a line or linkage attached to the boom to restrain its movement and prevent the sail from swinging violently if gusts alter the wind direction. It is typically rigged from the boom to a fixed point on deck or to a hard point on the vessel. Preventers help maintain steerage control and reduce the risk of injury to crew or damage to the vessel in heavy weather.

In oil and gas, the term is most associated with blowout preventers, devices installed on drilling rigs and wellheads to seal a well and control subsurface pressure. BOPs can include rams, annular preventers, and other subsystems. They are critical safety systems designed to prevent uncontrolled releases.

In general industry, preventers include safety interlocks, mechanical stoppers, pressure relief valves, and other fail-safe components that interrupt a hazardous process. Proper design, testing, and maintenance are essential to ensure they perform when needed. Standards often require redundancy and regular inspection.