US1951697A - Automatic pressure control - Google Patents

Description

March 20, 1934. E. w. KLEIN AUTOMATIC PRESSURE CONTROL Filed May 19. 1952 amnion E. M Klein patented Mar. 20, 1934 Nilii. STATES.

FATENT OFFI 3 Claims.

This invention relates to automatic control mechanism adapted to be applied to an ordinary reducing valve or similar weighted valve to regulate the flow therethrough of liquids or gases in accordance with variations in temperatures or pressures to which said mechanism may be exposed. By way of example, the invention is illustrated and described as applied to regulate the pressure of steam on the low side of a reduc- 19 ing valve in common use in steam heating systerns.

The main object of the invention is to provide control mechanism of this type which can be very readily manufactured and applied to a reducing valve to control the rate of flow of fluid therethrough either continuously and in proportion to variations in outside temperatures and/or pressures, or in irregular steps, as may be found necessary or desirable.

20 Other objects of the invention will become apparent as the detailed description thereof proceeds.

In the drawing:

Figure 1 is a diagrammatic layout of the apparatus embodying this invention; and

Figure 2 is a central vertical section through a modification of counterbalanced tank which forms an essential element of the invention.

In Figure 1 there is illustrated a high pressure 30 pipe 1 of a steam heating system screwthreaded at one end into the sides 2 of the casing of a reducing valve 3. A low pressure pipe 4 is similarly screwthreaded into the other side 4' of said casing. The inside of the casing, near the high pressure pipe 1 has a flange 5 extending toward the axis of the casing to support a U-shaped'diaphragm having a vertical wall 6 and substantially horizontal parallel walls '7 and 8 provided with detachable valve seats 9 and 10, respectively. 40 The seats 9 and 10 cooperate with the valve plates 11 and 12, which are mounted on the reciprocating rod 13 to control the flow of fluid from the high pressure side of wall 6 to the low pressure side thereof. These valve plates are provided with the usual radial vanes 14 to guide said plates properly toward and from their seats and permit the flow of fluid from high to low pressure side when the plates are unseated. This construction is in common use for reducing valves.

The rod 13 is mounted to slide through a packing gland 15 centered in the bottom closure plate of the casing 3, and in a sleeve 16 supported by the upper part 17 of the casing of a pressure regulator R. The lower end of rod 13. is connected to and supported by the disk diaphragm (o1. gee-92) (not shown) commonly used in this type of regulator. A control pipe 18 connects the lower part 19 of the casing of regulator 1'7 to the low pressure side of the system.

A counterbalance weight 20 is pivoted to the arm 21 of a lever L which pivots about a pin 22 extending laterally from a standard 23 depending from the casing 3 to form one of the supports for the casing of valve 1'7. A similar standard 24, similarly connected completes the support for regulator casing; and an adjustable set screw 25 provided with a lock nut 26, is arranged below the arm 27 of lever L to limit the downward movement of said arm 27.

The lever arm 27 is pivoted to the rod 13 by means of a pin fixed to and extending laterally from rod 13 through slots suitably formed in sleeve 16 and in said arm 27. A tank 28 is pivoted to the outer end of lever arm 27 by means of a bail 29; and a valve controlled pipe 30 connected to a source of water supply is suitably supported above tank 28 to conduct a trickle of water to said tank.

As shown in Figure 1, the tank 28 is funnel shaped and has one end of a flexible tube 31 connected to its apex. This tube 31 is bent upwardly andhas its upper end 32 carried by a suitable bracket 33 extending from one end of the arm as of a lever L1. The lever L1 is fulcrurned on the upper end of a standard 35 extending upwardly from the horizontal arm 36 of a bracket 37 suitably fixed to the side of tank 28.

A sylphon or similar bellows expansion member 38 is supported by the arm 36 and has its upper closed end connected pivotally by a lug 39 to the outer end of arm 34 of the lever L1. The lower end of the sylphon is connected by a flexible tube 4.0 to the lower end of a tank 41 suitably supported by bracket 42 on the outside of a wall 43 of the building in which the reducing valve mechanism is housed.

A funnel 4.4., at the upper end of waste piping 45, traps the overflow from the tube 31, and conducts it away from the apparatus.

In the set up of this apparatus, the expansible chamber or sylphon 38, the tube 40 and tank 11 are filled with oil or other suitable liquid when the expansion chamber 38 is fully expanded and the tank 41 is exposed to a predetermined outside temperature which, for example, may be approximately seventy degrees. At the minimum outside temperature for which the heating system is designed, the sylphon 38 would be fully contracted, due to the contraction of volume of the contained liquid with the drop in temperaure.

Obviously, this arrangement provides for movement of lever arm 34 from a given low position at which the reducing valve is fully closed to a maximum high position at which the reducing valve is fully opened. These movements vary with changes in the outside temperature to which the tank 41 is subjected.

The weight 20 is designed to counterbalance partly the weight of the tank 28 and the parts carried thereby. For example, if the heating system is so designed that one pound pressure is required for a complete circulation of steam, the tank 28 would be constructed of such size as to weight the reducing valve for one pound pressure at the minimum outside temperature.

The parts of the system are shown in the position occupied when the outside temperature is not less than seventy degrees. The sylphon 38 is fully expanded, the tank 28 is empty and raised to its highest position by the action of weight 20 on the lever arm 27 supporting tank 28, and the reducing valve is fully closed.

As the temperature decreases, the sylphon 38 contracts, and raises the lever arm 3% carrying with it the overflow end 32 of the pipe 31. Since the water in the tank 23 rises to the level of the upper bend in tube 31, it is obvious that as the lever arm 34 rises the weight of water in the tank increases. This increase in weight naturally increases the downward pull on the lever arm 27 and reduces the closing pressure exerted on the reducing valve. Continuing contraction of sylphon 38, causes increase in the height of overflow end 32 relative to the tank 28 with consequent increase in weight of water in tank 28 and further downward movement of lever arm 27 until the pressure on the reducing valve arrives at its minimum of one pound, with sylphon 38 fully contracted.

The vertical travel of the upper end of the expansion member 38 relative to its lower end is a continuous function of the first power of the temperature. The weight of the contents of the tank may be either continuous or discontinuous function of any power of the temperature, depending on the shape of the tank.

In the particular system illustrated herein, the steam pressure would probably be required to vary as the square root of the difference between the outside and inside temperatures; and the tank is so shaped that such regulation may be obtained. It is obvious that if the movements of the overflow end 32 of pipe 31 is in direct proportion to outside temperature, the tank 28 can be so shaped that graphs showing variations in the weight of the contents of the tank will follow a continuous straight line formula or a continuous curve.

It is also possible to construct a tank of such shape, by using horizontal offsets to effect a pressure control which is irregular in steps. A tank of this type is illustrated in Figure 2, and is intended as a substitute for tank 28, when this irregular control is desired. The modified form of tank comprises a cylindrical receptacle 46 connected at its bottom to a flexible overflow tube 31 similar in every respect to tube 31 and similarly supported at its free end by the lever system operated by sylphon 38. The upper edge of receptacle 46 is connected to the annular bottom 4'7 of a cylindrical receptacle 48 which, in turn, is connected to the annular bottom 49 of a receptacle 50. A bail 29' straddles the receptacle 50 to connect the stepped tank to the lever arm 2'7.

The variable weight tank acts as an automatically adjustable weight for varying the pressure on a valve and the tank may be shaped so that these variations in pressure follow a predetermined formula.

The most important feature resides in the idea of varying the weight or the contents of a tank by feeding a constant stream of liquid into the tank and automatically controlling the position of an overflow therefor through the action of a thermostat or pressurestat, and in accordance with changes in temperature or pressure. Another important feature lies in the application of this variable weight tank to a valve for controlling the flow of liquids or gases.

While I have described my invention as embodled in concrete form and as operating in a specific manner in accordance with the provisions of the patent statutes, it should be understood that I do not limit my invention thereto, since various modifications thereof will suggest themselves to those skilled in the art without departing from the spirit of my invention, the scope of which is set forth in the annexed claims.

What i claim is:

1. A pipe, a reducing valve in the pipe, a support in fixed relation to the valve, a pressure regulator fixed to said support, a rod connecting the pressure regulator to said valve to move the la ter in accordance with changes of pressure in the regulator, a lever pivoted between its ends to said support, a tank pivoted to one arm of said lever, means for slidably and pivotally connecting said arm to said rod, a counterbalance on the other arm of said lever, means for feeding a stream of liquid into said tank, an overflow connected to and movable with said tank, and means for varying the height of said overflow relative to its point of connection to said tank for varying the volume of the liquid content of the tank.

2. Reducing valve mechanism including a pressure control lever fulcrumed between its ends to a fixed part thereof, means for slidably and pivotally connecting one arm of said lever to said mechanism, a tank supported by said arm of said lever, a counterbalance on the other arm of said lever, a flexible overflow pipe having one end connected to the bottom of said tank, an expansible chamber supported adjacent said tank to move therewith, lever mechanism connected to said cl'iamber and operated by the expansion and contraction thereof to raise the free end of said overflow pipe relative to the bottom of said tank to vary the volume of liquid in said tank, and means exposed to the atmosphere and operated by changes in atmospheric condition to expand and contract said chamber.

3. A building having a heating system therein and including a casing, a reducing valve in said casing, a rod for reciprocating said valve in its casing, means for operating said valve in accordance with the temperature requirements of the system, said means comprising: a lever fulcrumed between its ends to a fixed part of the valve casing and having one arm slidably and pivotally connected to the said rod, a tank pivoted to the said arm, a counterbalance weight on the other arm of said lever, means for feeding liquid to said tank, a flexible overflow tube connected to the bottom of said tank, and means responsive to the atmosphere outside said building to vary the height of the free overflow end of said tube relative to the bottom of the tank.

EDW'ARD W. KLEIN.

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