Abstract: A valve comprises a valve body (2) defining a through passage (3), a branch passage (7), and an aperture (11) in the wall of the through passage. A closure member (12) is movable between a first position in which the closure member seals the aperture and a second position in which the closure member establishes communication between the through passage and the branch passage.

Abstract: A diaphragm valve comprises a valve sub-assembly including a diaphragm secured to a valve body by a clamping member. The clamping member is provided with screw threads on to which a drive assembly is screwed to complete the valve. The drive assembly may be a piston and cylinder drive assembly or a handwheel drive assembly. An indicator module to provide an indication of whether the valve is open or closed can be incorporated between the clamping member and the drive assembly. The drive assembly can be removed for service or interchanged without disturbing the fluid seal between the diaphragm and the valve body.

Abstract: A method of forming an injection moulded lining on a valve body comprises the step of defining a cavity having a main portion which when filled with lining material forms the desired lining, and an extension portion continuous with an edge of the main portion. Lining material is injected into the extension portion until the cavity is filled. Any sprues produced by the injection are on the tab formed by the material in the extension portion and not on the lining proper. Thus, there is no danger of damaging the lining as sprues are removed, and they do not cause local stress in the lining.

Abstract: A fluid flow control valve having a closure member movable by axial movement of a stem in which sealing means are provided between the valve body and a sleeve covering the part of the stem extending out of the valve body. Preferably the seal is a lip seal on a plastics sleeve secured to the body to provide an opening indicator and a lubricant reservoir.

Abstract: A ball valve having a seating ring held in a recess in the valve bore by threaded portions of the ring and bore such that, when the ring is in position, the threaded portion on it has passed right through the threaded portion of the bore, there being a radial expansion gap between part of the ring and the recess.