GB272242A - Improvements in liquid-operated regulating apparatus - Google Patents

Abstract

272,242. Carlstedt, R. June 7, 1926, [Convention date]. Apparatus.-In liquid-operated regulators comprising a piston servomotor, such as 1, Figs. 1 and 3, actuating a control member, such as a steam pressure regulating valve 12, the pressure supply of non-compressible liquid to the cylinder 1 is admitted on the side of the piston 2 remote from the piston rod 3 so that packing at the guide is obviated and a more sensitive control is obtained. In operation, a rise of steam pressure in the conduit 27 beyond the valve 12 is transmitted by the pipe 26 to the chamber 16 and there compresses the bellows device 17 which operates through the spring-controlled lever system 19 and increases the space between the pressure plate 20 and the nozzle 21. The consequent increased flow of liquid from the cylinder 23, admitted at 4, allows the piston to rise and, through the cord connections 9, throttles the valve 12. In the arrangement shown in Fig. 1, one end of the cord is anchored to the cylinder, at 10, the cord then passing over a pulley wheel on the end of the piston rod 3 and then to the valve which is counterweighted at 14. In the alternative arrangement shown in Fig. 3, the pulley is mounted on the cylinder 1 and the end of the cord is connected to the piston rod 3. The inlet passage 4, 5 for the liquid is provided with a cleaning pin 6.