A diaphragm valve of a type involved here includes a valve body, a compressor which can be actuated by a valve stem for operating a diaphragm. The compressor is guided by an intermediate piece in axial direction and restrained by the intermediate piece against rotation.BALANCING VALVES The compressor has two guide lands which radially jut out from the otherwise circular circumference of the compressor, for guidance in respective grooves in the wall of an intermediate piece of the diaphragm valve.Needle & Gauge Valves The wall of the intermediate piece is reinforced radially outwards in the area of the grooves, thereby creating necessarily bulges or ribs about the otherwise cylindrical outer circumference of the intermediate piece. The presence of such bulges or rib renders the required cleaning operation of the intermediate piece, especially when sterile valves are involved, complicated.Needle Valves A further drawback of this type of diaphragm valve is the absence of any pressure that can be applied onto the diaphragm and the valve body in the area of the grooves in the intermediate piece for guiding the compressor. The presence of the grooves also results in a breach in the application of a contact pressure, so that the fluid-tightness of this type of diaphragm valve cannot be ensured in this area, and there is also an added risk that the diaphragm becomes damaged by the radially outwardly projecting lands on the compressor.

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