Abstract: A break-away coupling device for use with a hoseline or pipeline for conveying hazardous fluids. The coupling comprises coupling members (10, 11) of generally tubular form for connection at their outer ends (14, 15) to a hoseline, pipeline or other fluid-supply or fluid-delivery point, and provided at their inner ends with complementary faces (12, 13) which are held in sealing engagement by frangible connectors (18). The coupling members have valve seats (45), and valve members (30, 31) which are urged towards closing engagement with said seats but are usually being held against the springs (36) and out of engagement with the seats until the coupling members are separated on breaking of the connectors. An annular separating ram (51) is provided to apply pressure between the coupling members which will break the connectors and separate the coupling members, whereupon the valve members will seat under spring action and minimize spillage of the fluid being conveyed.

Abstract: A break-away coupling for incorporation in a hoseline or pipeline, comprises a pair of tubular coupling members each being arranged at its one end for connection to a length of hoseline and provided at its other end with a face to be held in sealing engagement with a complementary face of the other member by frangible connectors. Each connector has one end length of spatulate shape and formed with a through opening to receive a shear pin, a screwed length at the other end to receive a nut, and an intermediate length of reduced section. Valve members in the coupling members are held in open positions against the action of springs until the coupling members are separated on breaking of the connectors; thereupon, the valve members close under spring action. A bleed passageway may be provided to prevent build-up of pressure between the complementary faces, and provide a seal testing facility.