Fluid flow-controller with improved diaphragm

Abstract

A diaphragm type fluid flow controller comprises a valve body having formed therein an inlet and an outlet passage, the passages communicating with a valve chamber formed in the valve body. The valve chamber is sealed by a flexible diaphragm. A threaded valve stem is rotated by a handle to cause pressure to be applied to the diaphragm to selectively open or close the valve. A stop ring limits movement of the valve stem in the direction of the diaphragm so that the pressure applied to the diaphragm is limited once the valve is closed. The diaphragm comprises a plurality of nested thin metal dome-shaped plates having upturned peripheral edges which are clamped between the stop ring and a rim formed on the valve body at the upper extent of the valve chamber. The plural plates insure air-tightness of the valve chamber because any rotation of the stop ring, resulting from tightening the valve after closure, is not transmitted to the lower-most diaphragm plate. The upturned edges make individual diaphragm plates easier to handle. In addition, plural nested plates may be assembled and inserted into a valve as a unit. The upturned edges of the plates make it easier to grip and remove the plates from a valve in instances where it is desirable to leave the valve in-line during the removal process.

Dependencies are inferred from the claim text.