A pressure reducing valve with a pressure chamber

Abstract

The present invention discloses a pressure reducing valve with a pressure chamber, which can change the output pressure of the pressure reducing valve by pressurizing or releasing the pressure chamber pressure from the outside; it includes a regulating assembly with a pressure chamber, a diaphragm and a valve core assembly, and also includes a piston assembly, the piston assembly is sealed and arranged in the regulating assembly, one end cooperates with the pressure regulating spring in the regulating assembly, and the other end cooperates with the diaphragm. This scheme retains the advantages of the diaphragm pressure reducer, and also has a safety protection function under diaphragm rupture. When the diaphragm fails and ruptures, even if it is affected by the spring force, the valve core will not be fully opened, and gas can still be transported normally; furthermore, the diaphragm is only affected by the inner pressure, not the outer pressure, and the inner pressure is protected by the piston assembly limit. When a failure occurs, the probability of diaphragm rupture is relatively low, which effectively overcomes the problems existing in the prior art.

Description

Technical Field

[0001] The invention relates to a pressure reducing valve technology, in particular to a pressure reducing valve technology with a pressure chamber (DOME). Background Art

[0002] Different gases are often used in many fields of industry, such as industrial gas welding, laboratory inspection, semiconductor industry or food packaging industry. For the convenience of storage and transportation, gases are usually compressed and stored in high-pressure gas cylinders. When used, the gas pressure must be reduced to the required pressure through a pressure reducing valve as needed.

[0003] In specific applications, there are single-bottle applications, where the pressure reducing valve only needs a single pressure reducing function. There are also applications where high-pressure gas cylinders are used for centralized gas supply in order to facilitate centralized control and management. In addition to the pressure reducing function, the pressure reducing valve used needs to have a control function.

[0004] The pressure reducing valve with control function is a pressure reducing valve with a pressure chamber (DOME). Figure 1 As shown, the commonly used pressure reducing valve 20 with a pressure chamber 21a is mainly composed of an adjusting component 21, a pressure reducing device diaphragm 22 and a valve core component 23. The part below the pressure reducing device diaphragm 22 (such as the valve core component 23) is the same as the conventional pressure reducing valve. The pressure regulating part (i.e., the adjusting component 21) is different from the conventional pressure reducing valve. The output pressure is controlled by two parts. One is that the pressure is regulated by the spring 21b as in the conventional pressure reducing valve; the other is that the valve cover cavity is used as the pressure chamber 21a, as a pressure loading chamber. The loading chamber pressure acts on the piston, converting the loading pressure into a force with the same effect as the spring loading, and transmitting it to the diaphragm, adding an additional force. The total loading force of the pressure reducing valve is the sum of the spring loading pressure and the additional loading pressure of the air pressure, which controls the actual output pressure of the pressure reducing device. The output pressure of the pressure reducing valve is changed by loading or releasing the pressure in the pressure chamber as needed.

[0005] The commonly used pressure reducing valve with pressure chamber is just to add pressure chamber to the conventional pressure reducing valve; or to add seal at the adjusting screw rod to facilitate adjustment at any time; or to change the diaphragm pressure sensing element to the piston pressure sensing element to improve the safety of use; while the valve bottom and valve core are the same as the conventional pressure reducing valve. Such a solution has the following problems in actual application (see Figure 1 ):

[0006] First, the single diaphragm structure has a great hidden danger. When the diaphragm fails and ruptures, the diaphragm cannot sense the pressure, and the spring force cannot make up for the balance. Under the action of the single spring force, the valve core will be fully opened, and the high and low chambers will be directly connected, threatening the safety of use;

[0007] Second, the diaphragm is under pressure both inside and outside. The internal pressure can be protected by the diaphragm baffle, but there is no protection against external pressure. When one side fails, the probability of the diaphragm rupture is relatively high.

[0008] In this case, a piston-type decompression structure is also used to eliminate some of the hazards. However, in actual work, the piston will move more or less, and there will be more or less leakage in the dynamic sealing structure. Secondly, the piston movement process will produce pollutants, which is not suitable for use with gases with purity requirements. Summary of the invention

[0009] In view of the problems existing in the actual use of the existing pressure reducing valve with a pressure chamber, the object of the present invention is to provide a high-reliability pressure reducing valve with a pressure chamber.

[0010] In order to achieve the above-mentioned purpose, the pressure reducing valve with a pressure chamber provided by the present invention includes an adjusting component with a pressure chamber, a diaphragm and a valve core component, and also includes a piston component. The piston component is sealed and arranged in the adjusting component, one end of which cooperates with the pressure regulating spring in the adjusting component, and the other end cooperates with the diaphragm.

[0011] Furthermore, the pressure reducing valve also includes an alarm component for monitoring the working status of the diaphragm and / or piston component.

[0012] Furthermore, a sealed cavity is formed between the piston assembly and the diaphragm, and the sealed cavity can be connected to a detector to form an alarm assembly.

[0013] Furthermore, the detector is a pressure detector.

[0014] Furthermore, the piston assembly cooperates with the valve cover in the regulating assembly to form a pressure chamber in the regulating assembly. The piston assembly converts the pressure in the pressure chamber into a force with the same effect as spring loading. It is attached to the diaphragm and combined with the spring loading force to form a total loading force to control the output pressure of the pressure reducing valve.

[0015] Furthermore, the piston assembly includes a piston body and a sealing member disposed on the piston body.

[0016] Furthermore, the matching end surfaces of the piston body and the diaphragm are boss structures.

[0017] The solution provided by the present invention retains the advantages of the diaphragm pressure reducer and has a safety protection function under diaphragm rupture. When the diaphragm fails and ruptures, even if it is affected by the spring force, the valve core will not be fully opened and the gas can still be transported normally. Furthermore, the diaphragm is only affected by the inner pressure but not the outer pressure, and the inner pressure is protected by the limit of the piston assembly. In the event of a failure, the probability of the diaphragm rupture is relatively low.

[0018] Furthermore, this pressure reducing valve solution also has a diaphragm rupture monitoring function, which can detect problems immediately, make plans in advance, and prepare for maintenance work.

[0019] In addition, when the pressure reducing valve is used, the piston size can be changed, and the relationship between the external loading pressure and the additional output pressure can be flexibly adjusted. It is suitable for different control pressures to achieve the same additional pressure output, which simplifies the control circuit and makes the control circuit design more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] Figure 1 This is a schematic diagram of the structure of a conventional control pressure reducer with a pressure bag;

[0022] Figure 2 is a cross-sectional view of a pressure reducer with a pressure chamber in an example of the present invention;

[0023] Figure 3 It is an exploded view of a pressure reducer with a pressure chamber in an example of the present invention. DETAILED DESCRIPTION

[0024] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0025] This solution is based on the structural characteristics of the diaphragm pressure reducing valve. A piston structure is added above the diaphragm in the pressure reducing valve, thereby forming a pressure chamber inside the pressure reducing valve, and the pressure in the pressure chamber is converted into a loading force by the piston. At the same time, the diaphragm is protected from the upper side, so that the diaphragm is only subjected to the pressure from the inside, not the pressure from the outside, and the piston structure is protected by the pressure from the inside. In this way, even if the diaphragm ruptures, the working gas and the control gas are completely isolated, and the two gases do not interfere with each other. The piston acts as a spare diaphragm (i.e., diaphragm), and the pressure reducer can still transport gas normally. At the same time, the piston retains the limiting function, and even if a fault occurs, the diaphragm (i.e., diaphragm) is protected and not easy to rupture.

[0026] On this basis, a pressure detector can be further added outside the cavity between the diaphragm and the piston. When one side of the diaphragm or the piston fails, the pressure in the cavity between the diaphragm and the piston will increase, and the working state of the diaphragm or the piston can be determined based on the detection result, which can serve as the basis for maintenance and repair.

[0027] In addition, when this solution is used in specific applications, it is also possible to adjust the piston diameter and the relationship between the air pressure loading value and the generated output pressure value. According to different control pressures, pistons of different diameters can be matched to produce the same additional output pressure, thereby reducing the need to add pressure control elements to adjust the output pressure corresponding to the air pressure loading due to different control pressures, thereby simplifying the control loop.

[0028] See also Figure 2 and Figure 3 , which shows a structural example of a pressure reducer with a pressure chamber given in this example based on the above principle.

[0029] As can be seen from the figure, the pressure reducer with a pressure chamber mainly includes a valve group 1, a piston 2, a valve cover 3, a pressure regulating spring 4, a spring button 5, an adjusting screw 6, a first nut 7, a second nut 8 and a diaphragm 9 in terms of its composition structure.

[0030] The valve group 1 is mainly composed of a valve body, a valve seat, a valve stem, a return spring, etc. The specific composition scheme is the same as the composition scheme of the valve group in the existing pressure reducing valve, and will not be repeated here.

[0031] For the valve group 1, the diaphragm 9 is arranged on the valve group 1, and the specific arrangement scheme is the same as the existing pressure reducing valve scheme, which will not be described in detail here.

[0032] As for the piston 2, the whole is a disc-shaped revolving body with a sealing ring, and the middle of the cylinder has a sealing groove, and a sealing ring 2-1 is arranged in the sealing groove. As an example, the two end faces of the piston 2 in this example respectively adopt a boss structure to facilitate the cooperation of the pressure regulating spring 4 and the diaphragm 9. The piston 2 of such a structure is placed in the valve cover 3 as a whole through the sealing ring 2-1 thereon, and the pressure chamber 3-1 is formed by sealing and isolating in the valve cover 3; at the same time, the top end of the piston 2 can cooperate with the diaphragm 9 to isolate the diaphragm 9 from the pressure chamber 3-1 in the piston 2, so that the diaphragm 9 is not subjected to the outer pressure in the pressure chamber 3-1, and at the same time, a limit protection is formed for the diaphragm 9; the piston 2 converts the pressure in the pressure chamber into a force with the same effect as the spring loading, which is attached to the diaphragm and synthesized with the spring loading force into a total loading force to control the output pressure of the pressure reducing valve. At the same time, a closed sealing chamber 2-2 is formed between the piston 2 and the diaphragm 9, which can be used for real-time monitoring of the working status of the piston 2 and the diaphragm 9.

[0033] The valve cover 3 is in the shape of a bell as a whole, and the lower opening thereof is a connecting thread matched with the valve body, the upper part of the connecting thread is a cylinder sleeve matched with the piston 2, the upper part of the cylinder sleeve is a spring cavity and a special-shaped guide cavity of the spring button 5, and the uppermost part is a hole matched with the adjusting screw 6. A monitoring hole 3-2 leading to the outside is provided between the cylinder sleeve of the valve cover 3 and the lower connecting thread, and the monitoring hole 3-2 is also connected to the closed sealing cavity 2-2 formed between the piston 2 and the diaphragm 9, and can be connected to an external monitoring instrument to monitor the pressure in the sealing cavity 2-2, and monitor the working status of the piston 2 and the diaphragm 9 in real time according to the change of the pressure in the sealing cavity 2-2.

[0034] The pressure regulating spring 4 is the same as a conventional pressure regulating spring, such as a coil spring.

[0035] The spring button 5 is a disc-shaped rotating body with a thread in the center to cooperate with the adjusting screw 6, and the outer edge is a polygonal anti-rotation guide ring.

[0036] The adjusting screw 6 has a threaded lower portion, a positioning boss in the middle portion, and a round rod with a sealing groove in the upper portion, in which a sealing member 6-3 is provided. The center of the adjusting screw 6 is a pressurized air vent 6-1, the top end of which is an external air pressure loading port 6-2 connected to an external air pressure source, and the bottom end is connected to the pressure chamber 3-1 in the valve cover 3.

[0037] The first nut 7 is used to be installed on the upper end of the adjusting screw 6 to tighten and loosen the matching structure between the adjusting screw 6 and the valve cover 3.

[0038] The second nut 8 is arranged at the lower part of the adjusting screw 6 to prevent the adjusting screw from being over-adjusted.

[0039] In the pressure reducer with pressure chamber thus formed, the piston 2 is placed in the cylinder sleeve position of the valve cover 3, and the pressure chamber 3-1 is formed between the inner chamber of the valve cover 3 and the piston 2 and the adjusting screw 6. The valve cover 3, together with the upper parts such as the piston 2, the pressure regulating spring 4, and the adjusting screw 6, is installed on the valve body assembly, pressing the diaphragm 9, forming a thin closed chamber 2-2 between the diaphragm 9 and the piston 2, and the monitoring hole 3-2 on the valve cover 3 is externally connected to a detector and communicated with the closed chamber 2-2 to realize real-time monitoring of the pressure in the closed chamber.

[0040] Therefore, the piston 2 also has the function of a diaphragm baffle, and is limited upward by the upper part of the cylinder sleeve of the valve cover 3, which has the function of protecting the diaphragm from excessive deformation.

[0041] Furthermore, the diameter of the piston 2 can be matched according to the needs in the pressure reducer with a pressure chamber. The piston 2 is provided with a pressure regulating spring 4, and the spring is provided with a spring button 5. A guide and anti-rotation device is provided between the spring button 5 and the valve cover 3. An adjusting screw 6 is provided at the center of the spring button 5. The adjusting screw 6 is placed on the top of the valve cover 3 and matches with the center hole on the valve cover 3. A sealing ring is provided at the matching position of the adjusting screw 6, and an external air pressure loading hole is provided at the center of the adjusting screw 6. The external air pressure loading hole is placed at the center, which is convenient for assembly and use, and the position of the external air pressure loading hole will not be different due to the different tightening positions of the valve cover 3; at the same time, a nut 7 is added to tighten and prevent loosening, which can effectively prevent loosening after adjustment.

[0042] When the pressure reducer with pressure chamber is working, gas is introduced from the inlet, and the adjusting screw 6 is rotated to move the spring button 5 downward to compress the pressure regulating spring 4 through the threaded pair between the screw rod and the spring button 5, and the spring force acts on the piston 2. The anti-rotation device on the outer edge of the spring button 5 prevents the spring button 5 from rotating.

[0043] The air pressure loading pressure is added from the external air pressure loading port and also acts on the piston 2. The two forces form a combined force and are transmitted to the diaphragm 9 through the piston 2, opening the valve core and converting it into the output pressure of the pressure reducer.

[0044] When working, the spring and air pressure are loaded together, the valve opens, and the output is at the set pressure. When control is required, the pressure in the pressure chamber can be closed and released, the output pressure is reduced, and only the spring loading pressure is retained. It is also possible to load air pressure into the pressure chamber, add an air pressure auxiliary force, and increase the output pressure.

[0045] If the diaphragm ruptures during a fault, the output air pressure will enter the closed chamber 2-2 formed between the diaphragm and the piston 2, maintain the pressure, and act on the lower part of the piston, which can still balance the combined force on the piston and maintain the opening degree of the valve core, instead of completely connecting the high and low pressures like a conventional pressure reducing valve, causing a greater dangerous fault. There is a pressure output at the monitoring hole, and an alarm signal is issued through the monitoring instrument. According to the alarm signal, the pressure reducing valve is judged to be faulty and maintenance is arranged.

[0046] If necessary, the piston diameter can be changed to adjust the ratio of the external loading gas pressure to the additional output pressure to suit different external loading control pressures.

[0047] From the above examples, it can be seen that this pressure reducer with pressure chamber scheme retains the advantages of the original diaphragm structure, while adding a piston structure between the diaphragm and the pressure regulating spring, forming a pressure chamber between the piston and the valve cover; an intermediate closed chamber is formed between the piston and the diaphragm, and the valve cover, forming a new type of pressure reducer with pressure chamber, which increases the safety protection function and reduces the risk of diaphragm rupture and failure. A monitoring hole leading to the intermediate closed chamber is also set on the valve cover to monitor the working conditions of the diaphragm and the piston, give an early alarm, and prepare for maintenance work in advance.

[0048] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A pressure reducing valve with a pressure chamber, comprising a regulating assembly with a pressure chamber, a diaphragm and a valve core assembly, characterized in that: It also includes a piston assembly, which is sealed and arranged in the adjusting assembly and is located above the diaphragm. One end of the piston assembly cooperates with the pressure-adjusting spring in the adjusting assembly, and the other end cooperates with the diaphragm. The piston assembly cooperates with the valve cover in the adjusting assembly to form a pressure chamber in the adjusting assembly. The top end of the piston assembly cooperates with the diaphragm, and a sealed chamber is formed between the piston assembly and the diaphragm, which isolates the diaphragm from the pressure chamber so that the diaphragm is not subjected to the external pressure in the pressure chamber, and at the same time forms a limit protection for the diaphragm. The piston assembly converts the pressure in the pressure chamber into a loading force, and at the same time forms protection for the diaphragm from the upper side, so that the diaphragm is only subjected to the internal pressure but not the external pressure. The center of the adjusting screw in the adjusting assembly is a pressurized vent hole, the top end of the pressurized vent hole is an external air pressure loading port connected to an external air pressure source, and the bottom end is connected to the pressure chamber.

2. The pressure reducing valve with a pressure chamber according to claim 1, characterized in that: The pressure reducing valve also includes an alarm component for monitoring the working status of the diaphragm and / or piston component.

3. The pressure reducing valve with a pressure chamber according to claim 2, characterized in that: The sealed cavity can be connected to a detector to form an alarm component.

4. The pressure reducing valve with a pressure chamber according to claim 3, characterized in that: The detector is a pressure detector.

5. The pressure reducing valve with a pressure chamber according to claim 1, characterized in that: The piston assembly includes a piston body and a sealing member arranged on the piston body.

6. The pressure reducing valve with a pressure chamber according to claim 5, characterized in that: The matching end surfaces of the piston body and the diaphragm are convex structures.

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