hätäsulun

Hätäsulun is a Finnish-language term used in safety engineering to describe devices and arrangements that rapidly halt a process in an emergency. The word combines hätä (emergency) and sulku (shut-off or valve). The form 'hätäsulun' is the genitive of hätäsulku and may appear in phrases such as 'hätäsulun toiminta' (the operation of an emergency shut-off). The term does not refer to a single standardized device; it covers a range of mechanisms designed to stop flows, power, or movements to prevent harm.

In practice, hätäsulun devices include emergency shut-off valves, emergency stop switches, interlocks, and automated control sequences that trigger a shutdown when sensors detect a fault or danger. They are used across process industries, utilities, and building systems to prevent injuries, equipment damage, and environmental releases.

Activation can be manual or automatic. Manual activation often relies on a pushbutton or lever; automatic activation relies on sensors, control logic, or interlocks. Actuators may be electric, pneumatic, or hydraulic, and designs frequently incorporate redundancy and diagnostic features to improve reliability.

Maintenance and testing are essential. Regular inspections, functional tests, clear restart procedures, and documentation are common requirements under safety standards and risk assessments. The hätäsulun concept aligns with broader safety goals, such as emergency stops, interlocks, and fail-safe control systems.