Overview

This European Standard describes the general requirements for flap valves used for explosion isolation. An explosion isolation flap valve is a protective system which prevents an explosion from propagating via connecting pipes or ducts into other parts of apparatus or plant areas. An explosion isolation flap valve can only stop the propagation of an explosion when it propagates against the direction of the normal process flow. It does not stop explosions running in the normal process flow direction. This European Standard specifies methods for evaluating the efficiency of explosion isolation flap valves. This European Standard is applicable only to explosion isolation flap valves which are intended to avoid explosion propagation from a vessel, in which an ignition of dust air mixtures may cause explosions, into other parts of the installation via connecting pipes or ducts. This standard covers isolation of such vessels that are protected by the use of explosion resistant devices and explosion venting (including flameless venting) or explosion suppression. This standard is based on the assumption that the explosion starts in a vessel and not in pipes or ducting. Explosion isolation flap valves are not designed to prevent the transmission of fire or burning powder transported by the normal process flow. This shall be taken into account in risk assessments. This European Standard is only applicable for dust explosions (deflagration) of chemically stable substances and their mixtures. This European Standard is not applicable for explosions of materials listed below, or for mixtures containing some of those materials: a) gases, vapours and hybrid mixtures; b) chemically unstable substances; c) explosive substances; d) pyrotechnic substances.

Document: references other documents

Document: referenced in other documents

Responsible national committee

NA 095-02-01 AA - Explosion protection systems (except flame arresters)  

Responsible european committee

CEN/TC 305/WG 3 - Devices and systems for explosion prevention and protection