GB802401A - Improvements in fluid pressure selector valves for telegauges - Google Patents

Abstract

802,401. Indicating liquid levels. HOBSON, Ltd., H. M., and MALUGANI, G. Jan. 4, 1957 [Jan. 5, 1956], No. 420/56. Class 123(1) [Also in Group XXIX] In a device for indicating the liquid level in any one of a number of tanks 24, Fig. 1, each tank which is vented to atmosphere, contains a stand pipe 28 that is connected by a line 23 to a selector valve 20; compressed air which is admitted to each stand pipe through an inlet 29 prevents liquid from entering the pipe, the excess air escaping from the bottom of the latter so that the pressure in each line is a measure of the contents of the corresponding tank. An outlet 30 from the selector valve casing communicates with one limb of a manometer 32 via a line 31 whilst the height of liquid in the other limb indicates on a scale 33 the level in any tank 24 chosen by manual operation of the selector valve 20. The air may be supplied to the line 31 instead of inlets 29. If the tanks are pressurized a common equalizing line is connected between the manometer measuring limb and each of the tanks 24, above the level of liquid therein, through a second selector valve in tandem with the valve 20. Each selector valve consists of abutting front and back plates 35, 34, Fig. 3, with an interposed seal 37, the back plate housing a number of spring-closed valves 39 each connected to one of the lines 23, Fig. 1; one extra valve 39, Fig. 3, is provided for test purposes. The valves 39 may be selectively operated by a projecting peg 47 on an arm 46 coupled to a spring-loaded knob 45. In operation the latter is pulled and rotated to bring the peg 47 opposite a selected valve 39, upon releasing the knob its spring- loading moves the arm and knob inwardly causing the peg 47 to open the valve 39. A pointer 49 attached to the knob co-operates with an indicator plate 50 that is marked with the valve positions. For test purposes the test valve 39 is opened to vent the selector valve casing to atmosphere whereupon the inlet of this valve 39 is sealed and if any of the remaining valves 39 are leaky the manometer height will increase and the defective valve is detected by rotating the knob 45 to each valve position until the same manometer height is again attained. According to the Provisional Specification the spring-closed valves may be of the "Schrader" (Registered Trade Mark) type.