Shut-off valve with seat cage supported by flexible diaphragm - has gaskets between collar and flange to permit relative axial movement between cage and body

摘要

The valve body (1) has an inlet (3) and outlet (4) separated by a wall (2) with a threaded hole (7) to receive the seat cage (10). The valve head (13) slides in the seat cage (10) and seals on the seat (12) when the valve is closed. The upper end of the seat cage (10) is supported by a flexible metallic diaphragm (15). the diaphragm (15) is welded or brazed at its inner edge to the chamfered edge (14) of the valve cage. The outer edge of the diaphragm (15) is gripped between the gaskets which seal the joint between the cover (20) and flange (21) of the body (1). This method of support permits limited axial movement of the seat cage (10) due to thermal expansion.