BS EN 730-2:2002 specifies the general requirements and tests for safety devices for fuel gases and oxygen or compressed air which do not incorporate a flame (flashback) arrestor used downstream of manifold, cylinder and (or) pipeline outlet regulators, and upstream of blowpipes for welding, cutting and allied processes.
This European standard does not specify the location of these devices in the gas system. It does not include requirements for safety devices which incorporate a flame arrestor which are covered by BS EN 730-1.