övertrycket

Övertrycket (Swedish for "the overpressure") denotes a condition in which the local pressure exceeds the ambient or reference pressure. In physics and engineering contexts it describes positive gauge pressure relative to surrounding atmospheric pressure. Overpressure is characterized by its magnitude, duration and rate of change, and is typically measured with units such as pascals, kilopascals or bars using manometers, pressure transducers or blast gauges.

Causes and contexts for övertrycket vary widely: in explosions and blasts it appears as a sudden shock wave that can cause structural damage and human injury; in enclosed or pressurized systems it arises from mechanical compression, thermal expansion, or gas generation; in buildings and cleanrooms intentional overpressure is used to prevent ingress of contaminants; in respiratory medicine and diving it is relevant to ventilation strategies and risks of barotrauma.

Effects depend on level and exposure time. Low, sustained övertryck can improve air control in HVAC systems, while high transient overpressure can rupture structures, shatter glass and harm biological tissues. Managing övertrycket involves design measures such as pressure relief valves, burst discs, controlled venting, and reinforcement of enclosures, alongside monitoring and safety procedures.

The term is used across disciplines including civil and mechanical engineering, occupational safety, medicine, and military science, with standards and best practices that address measurement, allowable limits and mitigation to reduce risks associated with excessive positive pressure.