BS EN 14994:2007

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Venting of enclosures
5 Venting of isolated compact enclosures
  5.1 General
  5.2 Venting of isolated compact enclosures
  5.3 Situations outside the constraints of the basic
       method (turbulence inducing elements, partially
       filled enclosures)
       5.3.1 General
       5.3.2 Elevated initial pressure
       5.3.3 Effect of initial turbulence
       5.3.4 Effect of partial filling
       5.3.5 Venting of enclosures containing turbulence
             inducing elements
  5.4 Elongated enclosures
       5.4.1 General
       5.4.2 Venting of elongated enclosures vented at
             each end
       5.4.3 Venting of elongated enclosures vented along
             the enclosure
  5.5 Pipes
  5.6 Interconnected enclosures
  5.7 Vent ducts
6 Supplementary design aspects
  6.1 General
  6.2 Positioning and shape of explosion vents
  6.3 Choice of venting device
  6.4 External effects
       6.4.1 General
       6.4.2 Flame effects
       6.4.3 Pressure effects
       6.4.4 Deflectors
  6.5 Recoil forces
7 Information for use
  7.1 Marking
  7.2 Accompanying documents
Annex A (informative) Assessment of the level of
        congestion in rooms containing turbulence
        including elements
Annex ZA (informative) Relationship between this
         European Standard and the Essential Requirements
         of EU Directive 94/9/EC
Bibliography

Describes the basic design requirements for the selection of a gas explosion venting protective system.

This European Standard specifies the basic design requirements for the selection of a gas explosion venting protective system. This European Standard, EN 14797 and EN 14460 form a series of three standards which are used together. NOTE 1 These three standards together represent the concept of gas explosion venting. NOTE 2 To avoid transfer of explosions to other communicating equipment one should also consider applying prEN 15089. This European Standard is applicable to: ? vent sizing to protect against the internal pressure effects of a gas explosion; ? flame and pressure effects outside the enclosure; ? recoil forces; ? influence of vent ducts; ? influence of initial temperature and pressure. This European Standard does not provide design and application rules against effects generated by detonation reactions or runaway exothermic reactions including decomposition in the gas phase. This European Standard is not applicable to: ? fire risks arising either from materials processed, used or released by the equipment or from materials that make up equipment and buildings; ? design, construction and testing of explosion venting devices, which are used to achieve explosion venting ); ? protection against overpressures caused by events such as overfilling, overpressurisation, fire engulfment, overheating etc. NOTE 3 Protection by venting against dust and hybrid explosions is specified in EN 14491.