Varying size diaphragm valve assemblies utilizing diaphragm of uniform size

Abstract

A diaphragm valve assembly includes a valve housing having two or more fluid ports and defining both a valve chamber extending therebetween for fluid flow therethrough and an access port leading into the valve chamber. A bonnet covers the access port and defines an opening therein through which a valve stem arrangement extends. The valve stem arrangement includes a valve seat disposed within the valve chamber. The valve stem arrangement is slidable through the opening in the bonnet between a first position, wherein the valve seat is disposed in sealing engagement with a fluid port to thereby define a closed position of the valve assembly, and a second position, wherein the valve seat is disengaged from the first fluid port to thereby define an open position of the valve assembly. A diaphragm surrounds and is attached to the valve stem arrangement to form a seal therewith. A bonnet insert is disposed about the diaphragm adjacent to the valve housing, and it is directly exposed to fluid flowing through the valve chamber. A clamp forcibly retains the bonnet to the valve housing and retains the bonnet insert between the bonnet and the valve housing. The diaphragm forms a seal with an inner portion of the bonnet insert, and an outer portion of the bonnet insert forms a seal with the valve housing. The bonnet insert and the diaphragm together thereby prevent fluid flowing through the valve chamber from escaping into the access port between the valve housing and the valve stem arrangement.