GB226047A - Improvements in automatic boiler feed regulators - Google Patents

Abstract

226,047. Wing-field, B. R. Jan. 10, 1924. Pilot valve apparatus.-In a thermostatic boiler feed regulator, the thermostat is arranged at an angle across the water fine of the boiler, and operates, by means of a pilot valve, a feed valve forming a separate unit which may be arranged at a distance. The thermostat comprises a lower chamber 1 connected by a long tube to the water space of the boiler, an upper chamber 2 connected by a short tube to the steam space of the boiler, and a connecting tube 3 having a small expansion coefficient. A metal rod 4 having a higher expansion coefficient is fixed at 5 and slides through a stuffing-box. A lever 8 is pivoted at 9 and its movements are controlled by the rod 4 and spring 12. The free end of the lever 8 operates a piston valve 16 having annular grooves 17, 17<a>, the latter being connected to the space at the end of the valve. The passage 18 is connected by a pipe 18a to the pressure chamber of the main valve, and the passages 19, 20 to the inlet and exhaust for the pressure medium. When the rod 4 is contracted due to a high water level in the boiler, pressure fluid passes into the chamber 21 of the main valve, keeping the valve closed. A reverse movement of the rod 4 places the chamber 21 to exhaust through the valve 16, and allows the spring 24 to open the valve. An alternative arrangement is described in which the valve 16 is replaced by a double-seated cone valve. In another form, the auxiliary valve is adapted to retain or release the pressure fluid which enters the pressure chamber of the main valve direct.