GB603717A - Improvements in flow-regulating valves with linear characteristics - Google Patents

Abstract

603,717. Fluid-pressure servomotor-control systems; piston valves. MASON-NEILA.N REGULATOR CO. April 20, 1945, No. 9991. Convention date, May 16, 1944. [Class 135] A valve 10, Fig. 1, for controlling the flow of liquid, e.g. oil, to the burners 30 of a steam generator, and in which the flow and the valve lift follow a linear law, comprises a valve body with inlet and outlet chambers, the flow between which is regulated, separated by a first member, e.g. the sleeve 59, Fig. 5, having a rectangular port 62, and a second member, e.g. the piston valve 26, for varying the port opening. The port, which is parallel to the piston axis, has the section shown in Fig. 4, including bevelled upstream edges 63 making an angle of between 25 degrees and 45 degrees with the port axis 65. The depth D of each bevel is between 20 per cent and 45 per cent of the depth T of the port, while T is between 75 and 150 per cent of the port width W. The instrument 11, responsive to the differential draft pressure across the furnace 17 through the pipes 18, 19, and supplied with fluid through the reducing valve 20, controls the movement of the diaphragm 24 which operates the valve 10 through the rod 27. The constant capacity pump 34 supplies oil in excess of the burner requirements and oil is byepassed by the valve 36 controlled by the diaphragm 39 responsive to the pressure drop across the valve 10.