High pressure regulator valve

Abstract: A valve-regulator assembly for rendering a high pressure gas source compatible with lower pressure equipment, said valve-regulator being sealable or remote from the high pressure gas source enabling recharging at high pressure.

Description: Technical Field This invention relates generally to the field of gas pressure regulation and, in particular, is an improvement for rendering a high pressure gas source compatible with a lower pressure use point. Background Art A recent very significant advancement in the field of gas storage vessels, such as gas cylinders, is the high strength steel cylinder developed by Union Carbide Corporation and described and claimed in US-A-4,461,657 - Rana et al. and US-A-4,578,113 - Rana et al. This new gas storage cylinder enables the storage and transport of significantly more gas than is possible in a conventional cylinder of comparable size and weight because the gas can be safely maintained within the new gas storage cylinder at a pressure much higher than that possible with such conventional cylinders. For example, whereas a conventional cylinder may safely hold gas at a pressure up to about 2700 psia, the new high pressure gas storage cylinder may safely hold gas at a pressure up to about 4500 psia. Gas is used at a use point at a defined pressure or pressure range. Generally this use pressure is less than the pressure of the gas source. In such cases a pressure regulator is employed to cause a reduction in the gas pressure and to ensure that the pressure of the gas going to the use point does not exceed the allowable use point pressure limit. Accordingly, many users of gases have regulators which can regulate the pressure of gas from about 2700 psia down to the desired use point pressure. As previously discussed, the new gas storage cylinder provides gas at a pressure significantly in excess of the conventional pressures and thus at a pressure greater than that which can be handled by conventional regulators. One solution is to change the regulator to one which can handle the higher pressures. However, this solution is costly and may be time consuming if a user switches frequently from one gas source to another because the user may also have to be switching regulators. It is thus desirable to have a regulator which can regulate high pressure gas, such as from the new high strength cylinder, for interfacing with existing pressure regulators designed to handle gas at lower pressures. Once the new high strength gas storage cylinder is empty of gas it must be refilled. In order to retain the advantages of the high strength cylinder it must be recharged at the high pressure. Thus it is further desirable to have a high pressure regulator which will also allow refilling of the cylinder at high pressure. Accordingly, it is an object of this invention to provide a regulator capable of rendering a high pressure gas source compatible with a lower pressure use point while also enabling recharging of the high pressure gas source to a high pressure. In a valve-regulator assembly known from document US-A-3 211 175 a sealing plug provided at one of the ends of a spring-loaded-piston cooperates with a seat of a seat member which is slidably mounted in a valve body . When high pressure is present in a sensing chamber provided at the end of the piston remote from the sealing plug , this high pressure also acts against the exposed upper end face of the seat member. This produces a downward force on the seat member overcoming the biasing upward force of a seat member spring . Therefore the seat member moves downwardly to provide a spacing between the opposing faces of the seat and the sealing plug. Thereby a tank carrying the valve-regulator assembly may be recharged via the low pressure outlet by connecting to the outlet a high pressure hose which is in flow communication with a high pressure source. In the valve-regulator assembly known from this document a high pressure safety plug is provided for communicating between the high pressure inlet of the valve-regulator assembly and the outside of the valve body. In normal use of the prior valve-regulator assembly a medium pressure hose is connected to the lower pressure outlet of the valve-regulator assembly through a fitting. This fitting is provided with an overpressure relief valve assembly. Summary Of The Invention The above and other objects which will become apparent to one skilled in the art upon a reading of this disclosure are attained by the present invention, as this is defined in the independent claim. As used herein, the term "high pressure" means a pressure in excess of 186 bar (2700 psia). As used herein, the term "lower pressure" means a pressure less than a particular defined high pressure. As used herein, the term "downstream" means further removed from the high pressure gas source with respect to gas flow from the high pressure gas source. As used herein, the term "use point" means the point, or interface, where lower pressure equipment receives gas from the lower pressure outlet of the present invention. Brief Description Of The Drawings Figure 1 is a top or plan cross-sectional view of one embodiment of the invention whereby gas may pass out of a cylinder either at a high pressure or at a lower pressure and the cylinder may be refilled at high pressure through the high pressure outlet. Figure 2 is a simplified cross-sectional view of a gas storage cylinder of typical design. Detailed Description The invention will be described in detail with reference to the Drawings. Referring now to Figure 1, valve-regulator assembly 20 comprises valve body 21 having main conduit 22 capable of flow communication with a high pressure source. For example, when the high pressure source is a gas storage cylinder, such as is depicted in Figure 2, assembly 20 would fit on top of the cylinder and gas from the cylinder would pass through the neck of the cylinder into main conduit 22. As previously mentioned, Figure 1 is a top cross-sectional view of assembly 20. High pressure outlet 23 is in direct flow communication with main conduit 22. In this way gas at high pressure may flow through outlet 23, through main conduit 22, and for, example, into the cylinder so as to recharge the cylinder at high pressure. In addition, high pressure gas from the cylinder may flow through main conduit 22 and through high pressure outlet 23 so as to deliver gas at high pressure should such high pressure delivery be desired. Also in direct flow communication with main conduit 22 is regulator 24. Preferably regulator 24 comprises piston 25 loaded by spring or springs 26. Sensing chamber 27 is at one end of piston 25 and sealing plug 28 is at the other end. Passage 29 communicates between sensing chamber 27 and low pressure outlet 30, which is in flow communication with main conduit means 22 and downstream of regulator 24. Lower pressure burst disc assembly 31 communicates between lower pressure outlet 30 and the outside of valve body 21. The burst disc assembly comprises a burst disc with gasket which are sealed in place by a threaded plug having an open center to complete a properly sized passage for relief flow if and when the disc bursts due to overpressure. Regulator 24 is set to lock at a predetermined desired pressure by procedures, such as adjusting the compression on springs 26, well known to those skilled in the art. For example, in the case where the high pressure gas is at 310 bar (4500 psia) and the use point equipment at the interface can handle gas at a maximum pressure of 207 bar (3000 psia), regulator 24 would be set to lock at a lower pressure, such as 138 bar (2000 psia), thus ensuring that gas exceeding the use point maximum pressure is not delivered. This occurs as follows. With high pressure outlet 23 plugged off, gas flows from the high pressure source through main conduit 22 and lower pressure outlet 30, and then on to a lower pressure use point. A conventional stepdown regulator may be upstream of the lower pressure use point to further reduce the pressure. The pressure of the gas within lower pressure outlet 30 will depend on the rate at which the use point is using the gas. Should the pressure in lower pressure outlet 30 rise to the 138 bar (2000 psia) of this example, gas flowing through conduit 29 will deliver this pressure to sensing chamber 27 causing spring-loaded piston 25 to move sealing plug 28 into position blocking off the passage from main conduit 22 so as to stop gas flow. When the pressure in lower pressure conduit 30 decreases below the setpoint, i.e. below 138 bar (2000 psia), piston 25 moves back and gas flow is resumed. In this way the use point sees gas at only conventional pressures and not at the high pressure of the high pressure source. Because of the high pressures involved, two precautions are built into the assembly. Burst disc assembly 31 serves to ensure that should regulator 24 fail, high pressure gas will be released through the burst disc assembly and thus not cause harm downstream. In addition, the chamber for springs 26 is vented to the outside of valve body 21 through passage 32 thus ensuring that should high pressure gas pass by the O-ring seals on either side of springs 26, such gas will be vented out of the assembly and not cause spring malfunction leading to regulator malfunction. In the case where gas flow is desired through high pressure outlet 23, lower pressure outlet 30 is blocked off by an appropriate plug. Now by the use of the present invention, one can advantageously employ a high pressure gas source, such as the new high pressure gas storage cylinder, while delivering gas to a use point safely at a lower pressure compatible with the equipment at the interface. Furthermore the invention enables recharging of the gas source, such as the gas cylinder, at the high pressure.

Claims: A valve-regulator assembly (20) for rendering a high pressure gas source compatible with a lower pressure use point comprising: (A) a valve body (21) having main conduit means (22) capable of flow communication with a high pressure source; (B) a regulator (24) in direct flow communication with said main conduit means (22), said regulator (24) comprising a spring-loaded piston (25), a sensing chamber 27) at one end of the piston (25), and a sealing plug (28) at the other end of the piston (25), and a passage (29) communicating between a lower pressure outlet (30) and the sensing chamber (27); (C) said lower pressure outlet (30) being in flow communication with said main conduit means (22) downstream of said regulator (24) characterized by: (D) a high pressure outlet (23) at the outside of the valve body (21) and in direct flow communication with said main conduit means (22) and this with the high pressure source; (E) said plug (28) being capable of stopping gas flow from the main conduit means (22) when high pressure is present in the sensing chamber (27); and (F) a lower pressure burst disc assembly (31) communicating between the lower pressure outlet (30) and the outside of the valve body (21). The assembly of claim 1 wherein the spring (26) is vented by a passage means (32) communicating between the spring area and the outside of the valve body (21). The assembly of claim 2 wherein the spring area is isolated on either side by O-ring seals concentric with the piston (25). The assembly of claim 1 wherein the passage (29) is within the piston (25).

Inventors: KIBLER VINCENT JOHN, PRITCHARD FRANCIS EDWIN, KIBLER, VINCENT JOHN, PRITCHARD, FRANCIS EDWIN
Applicants: PRAXAIR TECHNOLOGY INC, PRAXAIR TECHNOLOGY, INC.
Application year: 1988
Main classification: G05D16
IPC codes: G05D16, F16K17