VALVE ARRANGEMENT

Valve arrangement

A valve arrangement 10 comprises a base member 12 which may be mounted in an aperture 14 in the walls 16 of a flow passage 18, such as a pipe for extracting explosive gases from a mine. The base 12 supports at least one valve member 20 having a first position in which it may be withdrawn with the base member 12 through the aperture 14 and a second position shown in the drawing, in which the flow passage 18 is constricted by the member 20. The arrangement allows flow along pipe work to be restricted by inserting the base member and veins through existing inspection apertures in the pipes. As shown rotation of a shaft 28 moves in opposite directions threaded blocks 32 carrying fingers 36 which engage in slots 38 in valve members 20A- 20D. Alternatively a pair of semicircular valve members may be mounted on a diametrical base member to be swingable to respective sides thereof. ...