Explosion protection valve

Explosion protection valves are explosion decoupling solutions that are used in the context of constructive explosion protection and were first used in 1970. Constructive explosion protection is required when preventive explosion protection measures, such as an ignition source-free environment, are no longer sufficient. Different explosion protection valves are installed in systems that are connected to one another by pipes . In the event of an explosion, the spread of flames or pressure waves into the surrounding system is effectively prevented by the explosion protection valve closing the pipeline.

Explosion-related decoupling valves (e.g. Ventex) are mainly used in areas in which flammable dusts, gases or hybrid mixtures are processed. Such areas of application can be found predominantly in the pharmaceutical industry , in chemical / petrochemical companies, in the field of food and feed production as well as in research laboratories. A distinction is made between active and passive explosion protection valves: Passive explosion protection valves function without external energy and controls, only react to the effects of the explosion and, due to their structural properties, prevent flame and pressure from spreading within the pipelines and into adjacent system parts. Active explosion protection valves, on the other hand, require external energy and a control to close the pipeline. With the help of sensors that react to an increase in pressure or flames, they register the explosion and then immediately trigger countermeasures, i.e. closing the valve.

Operating principles

Passive explosion protection valves are integrated directly into the pipelines at a defined installation distance. In the idle state without air flow, the closing body of the explosion protection valve is in an open position. In normal operation, the medium that is transported through the pipeline flows around the open closing body. In the event of an explosion, the pressure wave presses the closing body against the closing body seal. In this closed state, the valve locks the line and thus prevents the spread of flames and pressure waves. The valves can - depending on requirements - be designed in such a way that they only function in the event of explosion hazards from the direction of flow, against the direction of flow or from both directions.

With active explosion protection valves, the system to be protected is equipped with a pressure or flame sensor. In normal operation, the medium flows around the closing body, the valve can simply be opened and closed pneumatically. The system control sends a signal that activates a gas generator. The pressure generated moves the closing body to the seal in just a few milliseconds.

literature

• Henrikus Steen (ed.): Manual of explosion protection. WILEY ‐ VCH Verlag GmbH, Weinheim 2000, ISBN 978-3-5272-9848-8 .
• Bernd Thier (ed.): Industrial valves. Components of pipeline technology, 5th edition, Vulkan Verlag, Essen 1997, ISBN 3-8027-2712-6 .

Individual evidence

1. ↑ Functional principle of the VENTEX explosion protection valves - RICO Sicherheitstechnik AG  ( page can no longer be accessed , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.  

Web links

• EC Guide (accessed on January 31, 2020)
• Hazardous explosive mixtures - measures of structural explosion protection, which limit the effects of an explosion to a harmless level (accessed on January 31, 2020)
• Dust explosion protection on machines (accessed on January 31, 2020)