GB538208A - Improvements in and relating to diaphragm valves - Google Patents

Abstract

538,208. Diaphragm valves. SAUNDERS VALVE CO., Ltd., and SUTTON, F. Feb. 17, 1940, No. 3058. [Class 135] A diaphragm valve of the "weir" type has the movement of the diaphragm compressor in the valve closing direction limited by a stop. In the form shown in Fig. 2 the casing opening opposite the weir 3 is surounded by an upstanding hollow cylindrical extension 7 to which the bonnet is secured. This bonnet is externally screwthreaded to engage the extension and internally threaded to engage an actuating screw 13. The inner end of the screw 13 has a collar engaging an undercut recess in the valve compressor which is slidably mounted in the bonnet. The diaphragm is clamped against an internal flange in the casing by the lower end of the bonnet bearing against an L-section ring embracing the diaphragm. This ring by engagement with the lower 'face of the compressor serves as the stop to prevent undue closing pressure being applied to the diaphragm. In a modified form constructed as a pillar cap the lock-nut 15 on the bonnet is replaced by a protective cap. In another form in which the diaphragm is clamped between two flanged parts splaying of the diaphragm is prevented by the L-section ring which is formed with radial fingers to support the diaphragm in the valve open position. The diaphragm compressor also has radial fingers adapted to pass between the support fingers until extensions on two of them opposite the weir contact with parts of the upper surface of the L-section ring and so prevent further movement. Specifications 321,892, [Class 135], 362,084, 434,664, 431,665, 434,684, 439,701, 442,790, 468,664, 516,526, 516,569, 517,887, 518,286, and 527,938 are referred to.