Patent GB-190314719-A (GB)
Title: Improvements in Valves Adapted to be Closed by the Pressure of the Fluid Controlled, and in Means for Automatically Operating such Valves.
Inventor: MARSHALL PETER
Filed: 1903-07-02
Granted: 1904-05-05
Abstract: 14,719. Marshall, P. July 2. Valves for automatic liquid supply; ball and float valves actuating valves ; casings floats; repairing, facilitating; shocks, preventing.-Relates generally to valves adapted to be clcsed by the pressure of the fluid controlled, and to means for operating such valves, the valves and valve-operating mechanism being particularly applicable for automatically controlling the supply of feedwater to high-pressure boilers, or to evaporators working under a partial vacuum &c. Fig. 1 shows the application to a boiler 11. The water is forced by the feed-pump through the inlet 3, and through the controlling valve 1, when open, to the outlet 2, from which it passes through a suitable checkvalve to the boiler. The upper end 1<b> of the valve 1 is of larger diameter than the seating face, the valve being seated by a back-pressure in the cbamber 5, which may be fed with water by leakage past the valve, or through a separate passage 6 controlled by an adjustable valve 7. The chamber 5 is connected by the passage 8 to the valve passages 8a, 8b, controlled by the valve 9, which is actuated automatically by the lever 13 of a float in the boiler &c. When the water level in the boiler falls, the valve 9 opens, and relieves the back-pressure in the chamber 5, on which the valve 1 opens communication for the feedwater between the passages 3, 2. The seat and passages of the valve 9 are formed in the plug 9<a>, which is secured by the nut 9<b> and can be removed to facilitate inspection or repair. The valve 1 can also be removed, on unscrewing the plug 24, and is cushioned by leakage water in the annular space shown below the shoulder formed by the larger diameter of the part 1<b>. The plug 9<a> is formed with an annular groove, which, in any position of the plug on its seating, affords communication between the passages 8, 8a. The valve 9 rests on the roller 14 on the lever 13, which is pivoted on an adjustable knife-edge 15 or otherwise. In the arrangement shown, the pivot 15 has a tail-piece 15<a> guided in the removable plug 18, and is mounted on an eccentric pin 16, which can be actuated by the external lever 20, to adjust the pivot. The lever 20 is formed with a quadrant slot 21, so that it can be locked in position by a screw and nut. When the pressures are not excessive, the lever 13 may be pivoted on the pin 16. Instead of a hollow float, which may not withstand high-pressures, a copper coil, a steel cylinder, or a solid structure is employed, and is counterbalanced, so that the displacement causes it to rise and fall with the water level. The float and counterweight may both be in the boiler, or both in a chamber in communication with the boiler ; or, the float may be in the boiler, and the counterweight in a chamber communicating with the boiler. As applied to evaporators working under a partial vacuum, the valve 9 is mounted on the lever 13. According to the Provisional Specification, one or more intermediate valves may be interposed between the valve 1 and the valve 9, each valve being controlled by the next in succession.