Non-electrical equipment for use in potentially explosive atmospheres - Protection by flow restricting enclosure "fr" included-in-kit BS 7430:1991

BS 7430:1991

For oxygen and helium gas mixtures

The method described is not suitable for measurement of the effective sound pressure level under ear-muffs in the case of impulsive noise nor for active noise reduction ear-muffs

Sand casting

Non-electrical equipment for use in potentially explosive atmospheres - Protection by flow restricting enclosure "fr" included-in-kit BS 7430:19911 Scope This document specifies the requirements for the construction and testing of flow restricting enclosures for non electrical equipment intended for use in potentially explosive atmospheres if the atmosphere outside the enclosure becomes explosive rarely and for short durations only. This document supplements the requirements in EN 134631 the contents of which apply in full to equipment constructed in accordance with this document. Equipment