F16K 17/406

Safety valves; Equalising valves, {e.g. pressure relief valves} with a fracturing member, e.g. fracturing diaphragm, glass, fusible joint {the fracturing member being a generally elongated member, e.g. rod or wire, which is directly connected to a movable valve member, the breaking or buckling of the elongated member allowing the valve member to move to a closed or open position}