British Standard Connectors

British standard valve outlet connections follow a few simple rules:
– If the gas mixture has a flammable and toxic component, then the BS 15 connectors are
used.
– If the gas mixture has a flammable component but no toxic component, then the BS 4
connectors are used.
– If the gas mixture has a toxic component but no flammable component, then BS 14
connectors are used.
– If the gas mixture has neither a toxic nor a flammable component, BS 3 connectors are used.