Small piston high pressure reducing valve

Abstract

The application provides a small-sized piston high-pressure pressure reducing valve, which comprises a valve body with an inner cavity, a sealing seat fixed in the inner cavity and having a throttling port at one end, a piston rod arranged in the inner cavity and having a spring sleeved on the outer periphery of the rod body, a piston fixed at one end of the piston rod and in sliding sealing with the inner cavity of the valve body, a first through hole arranged in the center of the piston, a valve rod fixed at one end of the piston rod and passing through the first through hole, the other end of the valve rod being matched with the throttling port to form an openable / closable sealing pair, a first gap being arranged between the valve rod and the piston rod and being directly communicated with an outlet, a reserved space being arranged between the piston rod and the outlet, a pressure relief seat being sleeved on the other end of the piston rod and being in abutment with the spring, a second gap being arranged between the pressure relief seat, the piston rod and the inner wall of the valve body, a first elastic sealing ring being arranged between the pressure relief seat, the piston rod and the inner wall of the valve body to form a seal, and an overpressure discharge port being arranged on the side wall of the valve body. The application has the advantages of compact structure, reliable sealing, sound elimination and automatic overpressure discharge, and can realize safe and stable operation under a single-stage large pressure difference.

Description

Technical Field

[0001] This application relates to the field of pressure reducing valve technology, specifically to a small piston-type high-pressure pressure reducing valve suitable for high-pressure applications. Background Technology

[0002] In the field of industrial automation, pressure reducing valves are widely used as key components for pressure regulation. High-pressure pressure reducing valves are mainly used in conjunction with high-pressure storage systems. Their core function is to reduce the pressure of high-pressure fluids to the pressure required by downstream equipment and maintain a stable outlet pressure.

[0003] With the continuous expansion of the application scenarios for pressure reducing valves, various industries have placed higher demands on the performance, size, and cost of high-pressure pressure reducing valves. In existing technologies, the gas source pressure of high-pressure storage stations is typically high (e.g., around 35 MPa), while the actual operating pressure of downstream customers is much lower than the gas source pressure (e.g., around 1 MPa). This necessitates the use of single-stage, two-stage, or even multi-stage pressure reducing valves in series to achieve the required operating pressure. This multi-stage pressure reduction method not only requires more installation space but also increases equipment procurement and maintenance costs. Furthermore, it suffers from the problem of cumulative errors in pressure regulation accuracy, making it difficult to meet the market's diverse demands for miniaturized, single-stage high-pressure differential, and low-cost high-pressure pressure reducing valves.

[0004] In the prior art, utility model patent with publication number CN209041686U discloses a piston-type branch pipe pressure reducing valve, which uses a piston as the pressure sensing element and is suitable for working conditions with pressures higher than 1.6 MPa and temperatures higher than 120℃. However, this structure does not have a silencing device or an independent overpressure discharge structure. In addition, the sealing materials are mostly rubber or metal, which is difficult to meet the requirements for long-term reliable sealing of high-pressure gases.

[0005] Another invention patent application, CN115325230A, proposes a pressure reducing valve with noise reduction function. Noise reduction is achieved by setting a multi-stage energy dissipator outside the valve stem, making it suitable for liquid media. However, this structure relies on the cooperation between the throttling cone and the cylinder liner, with the pressure-sensing chamber located above the piston. Furthermore, it lacks an integrated automatic pressure relief function, making it unsuitable for high-pressure gas scenarios and unable to achieve safe and stable operation under single-stage large pressure differentials. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the purpose of this application is to provide a compact, reliably sealed, and automatically overpressure-releasing small piston-type high-pressure pressure reducing valve that can achieve safe and stable operation under single-stage large pressure differential.

[0007] A first aspect of this application provides a miniature piston-type high-pressure pressure reducing valve, comprising: A valve body having an inner cavity, wherein the inner cavity is provided with a fluid inlet and an outlet; A sealing seat is fixed in the inner cavity, with one end forming a throttling orifice; The piston slides and seals with the inner cavity, and has a first through hole at its center; A piston rod, which slides and seals with the piston, is located in the inner cavity, and a spring is sleeved around the outer periphery of the rod. The valve stem has one end fixed inside the hollow interior of the piston rod, and the other end cooperates with the throttling orifice to form an openable / closeable sealing pair; there is a first gap between the valve stem and the piston rod that directly communicates with the outlet, and there is a reserved space between the piston rod and the outlet; the reserved space provides movement space for the piston rod and is also a pressure-bearing space at the outlet; A pressure relief seat is fitted onto the other end of the piston rod and abuts against the spring. The pressure relief seat, the piston rod, and the inner wall of the valve body have a second gap. A first sealing ring that can be elastically deformed is located between the pressure relief seat, the piston rod, and the inner wall of the valve body to form a seal. The side wall of the valve body is provided with an overpressure discharge port.

[0008] Optionally, when the outlet pressure exceeds the set value, the first sealing ring is temporarily unable to seal after being deformed by the axial compression of the piston rod. The fluid flows through the second gap between the pressure relief seat, the piston rod and the inner wall of the valve body to the overpressure discharge port and is discharged. After the outlet pressure is restored, the seal is re-established by its own elasticity.

[0009] Optionally, the pressure reducing valve further includes a pressure adjusting screw, which passes through the inlet end of the valve body cavity. The pressure adjusting screw is connected to the valve body and is fitted with a locking nut. The set value of the outlet pressure is adjusted by the pressure adjusting screw. When the pressure adjusting screw is rotated clockwise, the set value of the outlet pressure decreases, and when it is rotated counterclockwise, the set value of the outlet pressure increases.

[0010] Optionally, the pressure reducing valve further includes a silencer located in the inner cavity, the silencer being located downstream of the inlet and fixed within the valve body cavity, and the sealing seat being adjacent to the downstream of the silencer.

[0011] Optionally, the pressure reducing valve further includes a connecting seat, the connecting seat having a cavity coaxial with the inlet, the silencer and the sealing seat being sequentially disposed in the connecting seat, the connecting seat being inserted into the inlet end of the valve body cavity, and the locking screw being circumferentially connected and fixed to the connecting seat through external threads.

[0012] Optionally, the muffler is a porous sintered metal structure, which is fitted into the inlet flow channel of the valve body with a clearance fit; the muffler and the sealing seat are locked and fixed by locking screws.

[0013] Optionally, the sealing seat has an overall cylindrical structure, with an inner conical surface at one end near the valve stem that matches the outer conical surface at the end of the valve stem; the sealing seat is made of PEEK material.

[0014] Optionally, the pressure relief seat has a flat side facing the spring and an annular protrusion on the other side. The piston rod has a first step at the corresponding end. The first sealing ring is clamped in the annular cavity formed by the first step, the annular protrusion, and the inner wall of the valve body, which is coaxial with the piston rod.

[0015] Optionally, the inner cavity wall is provided with an integral limiting step, the length direction of the limiting step extends to the reserved space, and the space between the sealing seat and the limiting step forms a space for the piston to slide in the inner cavity; the piston rod is a hollow circular tube, arranged along the length direction of the limiting step, and the sealing diameter of the piston is larger than the sealing diameter of the piston rod and the pressure relief seat; the reserved space provides movement space for the piston rod, and is also the space where pressure is applied at the outlet.

[0016] Optionally, the valve stem is T-shaped in general. The head of the T-shape is fixed inside the hollow tube and close to the piston. The conical end of the T-shape is an outer conical surface. The rod extending from the conical end is a small-diameter section. The small-diameter section continues to extend to a large-diameter section. The large-diameter section extends to the head of the T-shape. The large-diameter section is located inside the hollow tube of the piston rod, and the first gap exists between the two.

[0017] Optionally, the silencer, sealing seat, piston, valve stem, piston rod, spring, and pressure relief seat are arranged sequentially along the same axis.

[0018] This application provides a compact, reliably sealed, and automatically overpressure-releasing small piston-type high-pressure pressure reducing valve. It employs a piston structure, resulting in rapid pressure stabilization, excellent performance, and superior sealing. Furthermore, a single pressure relief seat performs both spring seat and pressure relief functions, reducing the number of parts. Overpressure venting is achieved through the elastic deformation of the first sealing ring, eliminating the need for additional guides, ensuring rapid response and no jamming. The short overpressure relief channel and the self-resetting first sealing ring further enhance reliability. In situations where one, two, or even three pressure reducing valves were previously required to reduce pressure to the operating pressure, only one pressure reducing valve from this application is needed, significantly reducing costs and installation space requirements.

[0019] Other technical effects resulting from the additional features will be further illustrated in the corresponding embodiments. Attached Figure Description

[0020] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a cross-sectional view of the overall assembly of a small piston-type high-pressure pressure reducing valve according to an exemplary embodiment. Figure 2 for Figure 1 A partially enlarged schematic diagram of AA shown in the figure; Figure 3 This is an external view of a small piston-type high-pressure pressure reducing valve according to an exemplary embodiment; Figure 4 An exploded view of a small piston-type high-pressure pressure reducing valve according to an exemplary embodiment; Figure 5 This is a partial installation schematic diagram of a small piston-type high-pressure pressure reducing valve according to an exemplary embodiment; Figure 6 This is a partial schematic diagram of overpressure discharge according to an exemplary embodiment; Explanation of reference numerals in the attached figures: 1-Valve body; 2-Locking nut; 3-Pressure adjusting screw; 4-First sealing ring; 5, 6, 7-O-rings; 8-Pressure relief seat; 9-Valve stem; 10-Spring; 11-Silencer; 12-Piston rod, 12a-First step; 13-Piston; 14-Sealing seat; 15-Locking screw; 16-Overpressure discharge port; 17-Connecting seat; 18-Safety hole; 19-First gap; 20-Second gap; 21-Reserved space; IN-Inlet; OUT-Outlet. Detailed Implementation

[0021] The present application will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all fall within the protection scope of the present application. Parts not described in detail in the following embodiments can be implemented using existing technology.

[0022] In the description of the embodiments of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0024] In the description of the embodiments in this application, "multiple" means two or more, unless otherwise explicitly specified. In this application, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] The terms "comprising" and "having," and any variations thereof, in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or devices.

[0026] Currently, commonly used high-pressure pressure reducing valves often encounter a problem: the gas source pressure of high-pressure storage stations is too high, usually around 35MPa, while the actual pressure used by customers is only around 1MPa. It is necessary to go through one, two or even more stages of pressure reduction to reach the on-site operating pressure, which is far from meeting market demand.

[0027] To address the aforementioned issues, this application provides a small piston-type high-pressure pressure reducing valve. For ease of description, in the following embodiment description, upstream and downstream are defined by the fluid flow direction formed between the inlet (IN) and outlet (OUT).

[0028] like Figures 1-4As shown in one embodiment of this application, a small piston-type high-pressure pressure reducing valve includes: a valve body 1, a sealing seat 14, a piston rod 12, a piston 13, a valve stem 9, a spring 10, a pressure relief seat 8, and an overpressure discharge port 16. Specifically: the valve body 1 has an inlet (IN) and an outlet (OUT) within its inner cavity; the sealing seat 14 is fixed to the inner cavity of the valve body 1, located downstream of the inlet (IN), with one end forming a throttling orifice for controlling the flow path of fluid; the piston rod 12 is a hollow rod disposed within the inner cavity of the valve body 1, with a spring 10 sleeved around its outer periphery to provide restoring force; a sliding seal exists between the piston 13 and the piston rod 12, allowing the piston 13 to slide along the piston rod 12 within the inner cavity of the valve body 1, and a first through hole is provided at its center, axially penetrating the piston 13 for the piston rod 12 to pass through; the valve stem 9 is fixed inside the hollow piston rod 12, and the end of the valve stem 9 cooperates with the throttling orifice to form an openable / open ... The closed sealing pair has a first gap 19 between the valve stem 9 and the piston rod 12 that directly communicates with the outlet (OUT). There is a reserved space 21 between the piston rod 12 and the outlet (OUT), which serves as both the piston rod movement space and the pressure-bearing space at the outlet. The pressure relief seat 8 is sleeved on the other end of the piston rod 12 and abuts against the spring 10. There is a second gap 20 between the pressure relief seat 8, the piston rod 12 and the inner wall of the valve body 1. An elastically deformable first sealing ring 4 is provided between the pressure relief seat 8, the piston rod 12 and the inner wall of the valve body 1. The first sealing ring 4 seals the pressure relief seat 8, the piston rod 12 and the inner wall of the valve body 1. The side wall of the valve body 1 is also provided with an overpressure discharge port 16.

[0029] In the above embodiment, under normal conditions, the pressure reducing valve forms a seal between the pressure relief seat 8, the piston rod 12, and the inner cavity of the valve body 1 through the first sealing ring 4. The first sealing ring 4 is initially in a circular free state (when not under force). When the inlet gas of the pressure reducing valve is pressurized, the inlet fluid pressure pushes open the valve rod 9 and acts on the left end face of the piston 13, pushing the piston 13 to slide to the right. The piston 13 and the piston rod 12 are in a sliding seal fit. When the piston 13 moves to the right, it will drive the piston rod 12 to move to the right synchronously through the force of the sealing surface. The first sealing ring 4 is squeezed by the spring 10, the pressure relief seat 8, and the piston rod 12. The first sealing ring 4 is deformed into an ellipse with a long distance between the top and bottom points and a short distance between the left and right points. However, when the outlet pressure is over-pressurized, due to the excessive pressure, the deformation of the first sealing ring 4 is insufficient to support the seal between it and the valve body 1. At this time, the seal is temporarily ineffective, and the pressure will emerge from the second gap 20 between the pressure relief seat 8, the valve body 1, and the piston rod 12 and flow to the overpressure discharge port 16 to be discharged, thus achieving the venting function. When the pressure in the overpressure section is released and the pressure is restored, the piston rod 12 moves to the left, and the first sealing ring 4 deforms into an ellipse and seals with the valve body 1 again, thus re-establishing the seal. Figure 6In this embodiment, the reserved space 21 provides sufficient space for the movement of the piston rod 12. This space is also the space where pressure is applied at the outlet. When the pressure changes, the piston rod 12 will move left or right along the reserved space 21. In this embodiment, pressure reduction and relief are achieved through the cooperation of the first sealing ring 4, the piston rod 12, the pressure relief seat 8, and the valve body 1. There is no additional guide, the response is fast and there is no jamming. The overpressure relief channel is short, and the first sealing ring self-resets, resulting in high reliability.

[0030] Specifically, under normal operating conditions, the pressure relief seat 8 is located inside the valve body 1 and does not participate in any action, serving only as a support point for the spring 10. Fluid (high-pressure gas) enters from inlet P1, passes through the small hole in the sealing seat 14, pushes open the valve stem 9, and flows directly to the outlet through the first gap between the valve stem 9 and the piston rod 12. Then, pressure accumulates in the reserved space 21, pushing the piston rod 12 to the left. The piston rod 12 drives the valve stem 9 to the left, reducing the opening until the valve stem 9 contacts the sealing seat 14, achieving a seal again. This process repeats, and the piston rod 12, valve stem 9, and spring 10 can move left and right according to pressure changes, adjusting the pressure. When the outlet pressure exceeds the set value and enters an overpressure state, the pressure relief seat 8 moves to the left under the push of the piston rod 12. The first sealing ring 4 is axially compressed and deformed, causing the seal between the pressure relief seat 8, piston rod 12, and the inner wall of the valve body 1 to temporarily fail. Gas flows out along the second gap 20 and is discharged through the overpressure discharge port 16. (Refer to...) Figure 6 As shown, the red arrows at the top indicate the movement direction of the pressure relief seat 8 and piston rod 12, while the red arrows at the bottom indicate the gas flow path during overpressure discharge. Once the outlet pressure drops to a safe range, the piston rod 12 and pressure relief seat 8 move in opposite directions, the first sealing ring 4 returns to its original shape, re-establishes the seal, and closes the second gap 20. By setting the overpressure discharge port 16, the pressure reducing valve automatically discharges gas when the outlet pressure exceeds the set pressure by 20% to 40%. The deformation amount, pressure threshold, and sealing ring material of the first sealing ring 4 can be selected according to the actual application and existing technology, as long as they meet the above application requirements.

[0031] The embodiments described in this application improve upon the commonly used high-pressure pressure reducing valve structure by employing a piston-type structure, resulting in excellent pressure stabilization. The same pressure relief seat 8 simultaneously functions as a spring seat and pressure relief valve, simplifying the structure and enabling the outlet pressure to be reduced to a maximum differential pressure of 50 times or more than the inlet pressure. The opening stroke and self-resetting are achieved through the elastic deformation of the first sealing ring 4, ensuring high reliability. Furthermore, the overpressure discharge port 16 incorporates an automatic overpressure discharge function, making the product safer, more stable, reliable, and economical. A single pressure reducing valve can meet customer needs, significantly reducing costs and installation space.

[0032] In some embodiments of this application, the piston rod 12 is a hollow circular tube, with one end of the piston rod 12 slidably and sealingly connected to the piston 13. One end of the valve rod 9 is fixedly connected to the hollow circular tube and close to the piston 13. According to the pressure rules during operation, after the gas passes through the small hole of the sealing seat 14 and opens the valve rod 9, the piston 13 is subjected to a certain pressure, pushing the piston rod 12 to the right. The piston rod 12 then drives the valve rod 9 connected to it to move in the same direction, adjusting the throttling opening. At the same time, the other side of the piston 13 abuts against the spring 10 on the outer periphery of the piston rod 12. After moving a certain displacement and the pressure drops, the piston 13 can return to its original position under the restoring force of the spring 10. This embodiment adopts a piston structure, which has fast pressure stabilization speed, good effect, and good sealing performance. The maximum input inlet pressure can reach 40MPa, and the outlet pressure is adjustable, ranging from 0.7 to 2.0MPa. The maximum pressure difference between the inlet and outlet can reach 57 times.

[0033] To better regulate fluid pressure, in some embodiments of this application, the small piston-type high-pressure pressure reducing valve also includes a pressure adjusting screw 3. The pressure adjusting screw 3 passes through the inlet end of the inner cavity of the valve body 1, and is connected to the valve body 1 and equipped with a locking nut 2. Before use, the outlet pressure can be adjusted to the desired outlet pressure setting value using the pressure adjusting screw 3, and a stable air source is output through the preset compression amount of the spring.

[0034] During the pressure stabilization phase, the force exerted by the piston surface and the preload of spring 10 form a force balance. When the adjusting screw 3 is rotated to change the preload of spring 10, the outlet pressure required for balance changes synchronously, ultimately achieving the adjustment of the preset outlet pressure value. For example, rotating the pressure adjusting screw 3 counterclockwise increases the preload of spring 10, raising the preset outlet pressure value; rotating the pressure adjusting screw 3 clockwise decreases the preload of spring 10, lowering the preset outlet pressure value. After adjustment, the locking nut 2 is used to lock and prevent loosening.

[0035] Specifically, refer to Figure 3 As shown, two holes are provided on the outside of the valve body 1. The right hole is an overpressure discharge port 16, and the left hole is a pressure-limiting safety port 18. The pressure-limiting safety port 18 is positioned at the corresponding sealing seat 14 to balance the internal pressure of the valve body 1, thereby helping to stabilize the outlet pressure. By precisely controlling the orifice size, the amount of backflow gas can be adjusted, thereby improving the sensitivity and accuracy of pressure regulation. That is, the outlet setpoint cannot be too high. When increasing the pressure, the pressure adjusting screw 3 needs to be rotated counterclockwise. If it is rotated too much, the first sealing ring 4 will come out, losing its sealing performance, and the gas will be released directly through the overpressure discharge port 16, without any pressure regulation function.

[0036] To reduce noise under high pressure, in some embodiments of this application, the small piston-type high-pressure reducing valve also includes a silencer 11. The silencer 11 is located downstream of the inlet (IN) of the valve body 1 and fixed inside the valve body 1, with the sealing seat 14 disposed adjacent to the downstream of the silencer 11. The use of the silencer greatly reduces noise under high pressure.

[0037] Specifically, the silencer 11 is a porous sintered metal structure, typically made of porous sintered metal materials such as stainless steel or titanium alloy. These materials can withstand the impact of high-pressure gas while providing excellent noise reduction. Its internal structure is porous, with pore size and porosity designed to minimize obstruction to gas flow while reducing noise. The silencer 11 is fitted into the inlet channel of the valve body 1 with a clearance fit. This clearance fit not only simplifies the assembly process but also allows for quick replacement of the silencer 11 when necessary, improving maintenance convenience.

[0038] The pressure reducing valve equipped with the silencer 11, as described above, allows high-pressure gas to enter the valve body 1 through the inlet (IN) and flow through the silencer 11. The porous structure inside the silencer 11 reduces the airflow velocity and turbulence, significantly lowering the noise generated by the airflow. The silenced gas then flows to the sealing seat 14, where it is further regulated and depressurized through the throttling orifice of the valve stem 9, ultimately achieving a stable outlet pressure. In this process, the silencer 11 not only effectively reduces the noise generated by the flow of high-pressure gas but also ensures that the overall performance of the pressure reducing valve remains unaffected, providing users with a quiet and efficient pressure reducing solution.

[0039] Reference Figure 1 , Figure 4 and Figure 5 As shown, in order to ensure fluid control and stability, in some embodiments of this application, the overall structure of the sealing seat 14 can be cylindrical, with an inner conical surface at one end near the valve stem 9, which matches the outer conical surface at the end of the valve stem 9. For example... Figure 1 As shown, a circumferential groove is provided in the middle of the cylindrical surface of the sealing seat 14, and a second sealing ring 6 is placed in the groove to keep the sealing seat 14 and the valve body 1 sealed.

[0040] Specifically, the sealing seat 14 has a small hole at its center for fluid to flow from the high-pressure inlet to the low-pressure outlet (serving as a fluid channel). An inner conical surface at the end of this small hole forms a throttling orifice, which is a gradually expanding trumpet shape (small inlet, large outlet). Correspondingly, the valve stem 9 has an outer conical surface at its corresponding end. The tip of the outer conical surface can extend into the throttling orifice and form a seal against the small hole. The shapes of the inner and outer conical surfaces allow the valve stem end to mate with the throttling orifice to form an openable / closeable sealing pair. That is, the valve stem 9 end can extend into the throttling orifice to form a seal (cutting off the fluid) or leave the throttling orifice (allowing the fluid to pass through), thereby controlling the flow of fluid. Furthermore, by changing the opening between the valve stem 9 end and the throttling orifice, the fluid flow rate and outlet pressure can be adjusted.

[0041] When the valve stem 9 moves to the right, the outer conical end of the valve stem 9 leaves the throttling orifice, allowing fluid to flow from the high-pressure side to the low-pressure side through the throttling orifice. At this time, the fluid pressure decreases, achieving the pressure reduction function. When the outer conical surface of the valve stem 9 presses against the inner conical surface of the sealing seat 14, the end of the valve stem 9 seals the throttling orifice, preventing fluid from passing through, thereby closing the flow path of the fluid through the throttling orifice.

[0042] In a preferred embodiment, refer to Figure 1 As shown, the valve stem 9 is T-shaped. The head of the T-shape is fixed inside the hollow cylindrical tube of the piston rod 12 and close to the piston 13. The conical end of the T-shape is an outer conical surface, which can fit well with the sealing seat. The rod extending along the outer conical surface is a small-diameter section, which continues to a large-diameter section. The large-diameter section extends to the head and is located inside the hollow cylindrical tube of the piston rod. There is a first gap 19 between the large-diameter section, the head, and the inner wall of the piston rod 12. After the fluid comes out from the throttling port, it flows through the first gap 19 along the inside of the piston rod 12 to the outlet. In this embodiment, this structural design can quickly and reliably complete the pressure relief when the fluid outlet pressure is overpressured.

[0043] To ensure sealing and service life under high pressure conditions, in some embodiments, the sealing seat 14 can be made of PEEK (polyether ether ketone) material. PEEK material can withstand high pressure, typically up to 40 MPa. For example, glass fiber reinforced PEEK can withstand 70 MPa, and carbon fiber reinforced PEEK can withstand up to 100 MPa. Its mechanical properties include high strength, high rigidity, excellent creep resistance and fatigue resistance, excellent heat resistance, and the ability to withstand high temperatures of 200°C for extended periods. It also has an extremely low coefficient of friction and excellent wear resistance, as well as self-lubricating properties. Furthermore, it has good corrosion resistance, can withstand most chemical media, and has a service life far exceeding that of metals.

[0044] It should be noted that in other embodiments, other materials may also be used, as long as they meet the above-mentioned conditions such as high pressure and heat resistance.

[0045] Reference Figure 1 , Figure 4 As shown in some embodiments of this application, in order to ensure the response and reliability of the pressure relief function, the pressure relief seat 8 is flat on one side facing the spring 10, and an annular protrusion is provided on the other side. The piston rod 12 is provided with a first step 12a at the corresponding end. The first sealing ring 4 is clamped in the annular cavity formed by the first step 12a, the annular protrusion and the inner wall of the valve body 1. The annular cavity is coaxial with the piston rod 12.

[0046] Specifically, refer to Figure 1 As shown, the piston rod 12 has two annular steps at its end away from the piston, with the diameter of the first step being smaller than that of the second step. One side of the pressure relief seat 8 is a flat surface that abuts against one end of the spring, serving to support the spring. The other side of the pressure relief seat 8 has an annular protrusion that engages with the two annular steps of the piston rod 12 to form an annular chamber. The first sealing ring 4 is located within this annular chamber, and when the pressure relief valve outlet is under stabilizing pressure, the first sealing ring 4, the steps, the annular protrusion, and the inner wall of the valve body 1 form a seal. The shape of the annular chamber is not circular, and the first sealing ring 4 does not completely fill the entire annular chamber in its free state. The annular protrusions overlap the first step 12a in an alternating manner, with an arc on the inner side of the annular protrusion. The end of the piston rod 12 is disc-shaped. When the first sealing ring 4 is accommodated and in its free state, part of it matches the arc of the annular protrusion, part of it contacts the inner surface (flat surface) of the disc, and part of it contacts the inner wall (flat surface) of the valve body, thus sealing the second gap 20.

[0047] In the preferred embodiment described above, when high-pressure gas enters through inlet IN, it reaches the throttling orifice of sealing seat 14 after being equalized and reduced in noise by silencer 11 (if applicable). After the gas pressure is reduced, it acts on the left end face of piston 13. The right end face of piston 13 is balanced by the preload force of spring 10, and the outlet pressure is stabilized at the design value.

[0048] Reference Figure 1 and Figure 4 As shown, in order to further improve stability and sealing, in some embodiments of this application, the small piston-type high-pressure pressure reducing valve also includes a connecting seat 17, which is disposed at the inlet end of the inner cavity of the valve body 1.

[0049] Specifically, the connecting seat 17 has a cavity coaxial with the inlet. The silencer 11 and the sealing seat 14 are sequentially arranged in the connecting seat 17. The connecting seat 17 is inserted into the inlet end of the inner cavity of the valve body 1. The external thread of the locking screw 15 is connected and fixed to the internal thread of the connecting seat 17. The sealing seat 17 and the silencer 11 are locked and fixed by the locking screw 15. All three components are located in the cavity of the connecting seat 17. The pressure adjusting screw 3 passes through one end of the connecting seat 17 and is locked from the outside of the connecting seat 17 by the locking nut 2.

[0050] In the above embodiments, the silencer 11, sealing seat 14, and connecting seat 17 are designed as detachable modules, facilitating installation, maintenance, and replacement. This modular design simplifies the assembly process and reduces maintenance costs. The sealing seat 14 and silencer 11 are locked together by locking screws 15, improving the strength and stability of the entire structure. The pressure adjusting screw 3 passes through one end of the connecting seat 17 and is locked from the outside of the connecting seat 17 by locking nut 2, making pressure adjustment more convenient. The outlet pressure can be adjusted directly by rotating the pressure adjusting screw 3 without disassembling other components.

[0051] Additionally, it should be noted that, in order to improve the sealing performance of the miniature piston-type high-pressure pressure reducing valve, the miniature piston-type high-pressure pressure reducing valve in this application also includes multiple O-rings, such as... Figure 1 Components 5, 7, etc., have O-rings installed at various contact points, such as between the muffler and the sealing seat, between the sealing seat and the connecting seat, between the connecting seat and the valve body, between the valve body and the piston rod, and between the piston rod and the piston. All O-rings can be made of PEEK (polyether ether ketone) material. O-rings can be installed at locations requiring sealing, depending on actual needs.

[0052] To improve the installation stability of the components inside the valve body 1, the silencer 11, sealing seat 14, piston rod 12, spring 10, pressure relief seat 8, and first sealing ring 4 are arranged sequentially along the same axis, which ensures stability and allows for quick replacement and maintenance.

[0053] The following specific preferred application examples will be used to further illustrate this application in order to better understand the above technical solutions of this application. It should be understood that the following are only some examples and are not intended to limit this application.

[0054] A preferred embodiment of this application provides a small piston-type high-pressure pressure reducing valve, comprising: a valve body 1, a locking nut 2, a pressure adjusting screw 3, a first sealing ring 4, O-rings (5, 6, 7), a pressure relief seat 8, a valve stem 9, a spring 10, a silencer 11, a piston rod 12, a piston 13, a sealing seat 14, a locking screw 15, an overpressure discharge port 16, and a connecting seat 17. See details below. Figure 1 and Figure 4 As shown, valve body 1 is a one-piece molded metal shell with an external cylindrical shape. Its compact design allows for installation in confined spaces. An internal cavity is formed. The high-pressure inlet IN is used to connect high-pressure fluids up to 40MPa, while the outlet OUT is used to output depressurized fluids at 0.7~2.0MPa. An end cap can be installed at the outlet.

[0055] The aforementioned components are located within the inner cavity of valve body 1. Connecting seat 17 is inserted into the inner cavity of valve body 1 from the inlet end and connected via locking nut 2 and pressure adjusting screw 3. Connecting seat 17 has an internal cavity where a silencer 11 and sealing seat 14 are sequentially installed. The throttling orifice at the end of sealing seat 14 mates with the end of valve stem located within the inner cavity of valve body 1. The valve stem is fixedly located inside hollow piston rod 12, and piston rod 12 is slidably and sealingly connected to piston 13. The inner wall of valve body 1 has an integral limiting step to restrict the range of piston 13 sliding along piston rod 12 within the inner cavity; specifically, it restricts piston 13 from sliding between sealing seat 14 (or connecting seat 17) and the limiting element. A spring 10 is sleeved around the outer periphery of hollow piston rod 12. The other end of hollow piston rod 12 mates with one side of pressure relief seat 8 and the inner wall of valve body 1 to form an annular chamber that clamps the first sealing ring 4. An overpressure discharge port 16 is located on one side of valve body 1.

[0056] The inner wall of valve body 1 is provided with a piston limiting step, which extends to the reserved space 21 (before the outlet) in the length direction. The space for piston 13 to slide in the inner cavity of valve body 1 is between the sealing seat 14 and the limiting step. Piston rod 12 is set along the length direction of the limiting step. Under this structural design, piston 13 will touch the limiting step when it moves to a certain position to the right. When the outlet pressure is large, the gas pressure in the reserved space 21 at the right end of piston rod 12 will push piston rod 12 to the left, and correspondingly drive pressure relief seat 8 to move to the left as well. The sealing diameter of piston 13 is equivalent to the diameter of the inner cavity. Due to the design of the limiting step, piston rod 12 and pressure relief seat 8 are located at the limiting step of the inner cavity. The sealing diameter of piston rod 12 and pressure relief seat 8 is smaller than that of piston 13 (difference of one limiting step size). Thus, when subjected to force at the same time, the surface with the larger sealing diameter is subjected to greater force. The force-bearing surface on the left side of piston 13 is greater than that on the right side of piston rod 12, so piston 13 will move to the left.

[0057] In this embodiment, the connecting seat 17 has a stepped hole inside, with the large-diameter section communicating with the inlet of the valve body 1. The pressure adjusting screw is located in the large-diameter section, and a silencer 11 and a sealing seat 14 are located in the small-diameter section. The silencer 11 is a porous sintered metal structure (e.g., porosity 30%-50%, pressure resistance ≥40MPa), and is fitted into the connecting seat 17 with a clearance fit. The valve stem 9 and the piston rod 12 can be detachably connected by snap-fit ​​or other means. A step can be provided inside the piston rod 12 to strengthen the axial positioning of the valve stem 9. The piston 13 can be press-fitted onto the outer circumference of the piston rod 12 and dynamically sealed with the inner cavity of the valve body 1. The pressure relief seat 8 is a disc structure, with a flat surface facing the spring 10 and an annular protrusion on the other side. The central hole of the pressure relief seat 8 is clearance-fitted with the piston rod 12.

[0058] The connection and installation of other components can be referred to the descriptions in the above embodiments, and will not be repeated here.

[0059] Based on the components of the above preferred embodiments, the working process of high-pressure gas after passing through the silencer 11 and the sealing seat 14 under different pressure conditions is analyzed as follows: (1) Initial state (off state): When the valve is not supplied with high-pressure gas, Figure 1 The pressure P2 at the outlet shown is 0. Piston 13 approaches sealing seat 14 (or connecting seat 17, if any), spring 10 is preloaded, providing initial thrust to valve stem 9. Sealing seat 14 contacts valve stem 9, forming a seal, the orifice opening is zero, the first sealing ring 4 is free, the second gap 20 is sealed, the overpressure discharge channel is sealed, and overpressure discharge port 16 does not discharge.

[0060] (2) Stabilization stage: After high-pressure gas is introduced into the inlet, the inlet pressure P1 is reduced and buffered by the silencer 5 and the sealing seat 14, and then acts on the valve stem 9, opening the valve stem 9 and the throttle port. The gas reaches the left end face of the piston 13, and part of it reaches the outlet through the first gap 19 between the valve stem 9 and the piston rod 12. When the outlet pressure P2 is stable within the set range (e.g., 1 MPa), the pressure on the piston 13 and the spring force reach force balance. At this time, the valve stem 9 is stable in a certain position range (the throttle port opening is stable), maintaining the stability of the outlet pressure P2.

[0061] (3) Overpressure stage: When the outlet pressure P2 exceeds the set value, the outlet pressure (at the reserved space) pushes the piston rod 12 to move to the left, the pressure relief seat 8 also moves to the left, and the spring 10 is also compressed. At this time, although the first sealing ring 4 is compressed, it can still maintain the sealing state of the second gap 20. The piston rod 12 drives the valve rod 9 to move to the left, adjusts the size of the throttle opening, releases the excess pressure, and the outlet pressure P2 begins to decrease.

[0062] (4) Overpressure emission stage: If the outlet pressure P2 continues to increase, the piston rod 12 and the pressure relief seat 8 continue to move to the left, and the spring 10 continues to be compressed until the first sealing ring 4 is deformed by compression, causing the sealing state of the second gap 20 to temporarily fail, triggering overpressure discharge. At this time, the gas at the outlet flows through the second gap 20 to the overpressure discharge port 16 and is discharged, rapidly reducing the outlet pressure P2.

[0063] (5) Reset phase: As the outlet pressure P2 decreases, the restoring force of spring 10 pushes the pressure relief seat 8 and piston rod 12 to move to the right and reset, the first sealing ring 4 re-establishes a seal, and the overpressure discharge port 16 no longer vents. Valve stem 9 re-contacts the sealing seat 14, closes the throttling port, restores the initial sealing state, and the outlet pressure P2 stabilizes below the set value.

[0064] Under normal operating conditions, the first sealing ring 4 provides a static seal between the pressure relief seat 8, the piston rod 12, and the inner wall of the valve body 1. When the outlet pressure exceeds the set value or changes, the piston rod 12 is pushed, causing the pressure relief seat 8 to move to the left. As the outlet pressure increases, the first sealing ring 4 temporarily fails to seal due to compression deformation, allowing gas to escape through the second gap 20 from the overpressure discharge port 16 on the side wall of the valve body 1. During this process, the pressure relief seat 8, the first sealing ring 4, and the piston rod work together to relieve pressure. After the pressure decreases, the first sealing ring 4 returns to its original shape due to its elasticity, re-establishing the seal. Through this design, the first sealing ring 4 not only improves the safety and reliability of the pressure reducing valve but also simplifies the structure and reduces the number of parts.

[0065] Throughout the entire operating process described above, the compression and rebound of spring 10 respond to changes in outlet pressure. In conjunction with piston rod 12, pressure relief seat 8, first sealing ring 4, and overpressure discharge port 16, the opening of the throttling orifice is controlled by adjusting the contact between valve stem 9 and sealing seat 14, thereby achieving stable control of outlet pressure P2 and overpressure protection. The specific parameter design of each component is determined based on actual application requirements and component materials, while meeting the aforementioned structural and operational requirements.

[0066] Actual testing of the product showed that the pressure reducing valve in this embodiment can achieve a maximum pressure difference of 57 times between its inlet and outlet, and the outlet pressure can be reduced to 50 times or more of the inlet pressure. The pressure reduction effect that previously required 1-3 pressure reducing valves can now be achieved with just one valve, significantly reducing equipment procurement costs and installation space. It is economical and energy-saving. Furthermore, the force balance between the piston and spring achieves rapid pressure stabilization, making it more stable and reliable in use. By further incorporating a silencer, noise can be greatly reduced.

[0067] The foregoing has described some specific embodiments of this application. It should be understood that this application is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this application. The above-described preferred features can be used in any combination without conflict.

Claims

1. A small piston-type high-pressure pressure reducing valve, characterized in that, include: A valve body having an inner cavity, wherein the inner cavity is provided with a fluid inlet and an outlet; A sealing seat is fixed in the inner cavity, with one end forming a throttling orifice; The piston slides and seals with the inner cavity, and has a first through hole at its center; A piston rod, which slides and seals with the piston, is located in the inner cavity, and a spring is sleeved around the outer periphery of the rod. The valve stem has one end fixed inside the hollow interior of the piston rod, and the other end cooperates with the throttling orifice to form an openable / closeable sealing pair; there is a first gap between the valve stem and the piston rod that directly communicates with the outlet, and there is a reserved space between the piston rod and the outlet; A pressure relief seat is fitted onto the other end of the piston rod and abuts against the spring. The pressure relief seat, the piston rod, and the inner wall of the valve body have a second gap. A first sealing ring that can be elastically deformed is located between the pressure relief seat, the piston rod, and the inner wall of the valve body to form a seal. The side wall of the valve body is provided with an overpressure discharge port.

2. The miniature piston-type high-pressure pressure reducing valve according to claim 1, characterized in that: When the outlet pressure exceeds the set value, the first sealing ring is temporarily unable to seal after being deformed by the axial compression of the piston rod. The fluid flows through the pressure relief seat, the second gap between the piston rod and the inner wall of the valve body to the overpressure discharge port and is discharged. After the outlet pressure is restored, the seal is re-established by its own elasticity.

3. The miniature piston-type high-pressure pressure reducing valve according to claim 1, characterized in that: It also includes a pressure adjusting screw, which passes through the inlet end of the valve body cavity and is connected to the valve body and is fitted with a locking nut; The set value of the outlet pressure is adjusted by the pressure adjusting screw. When the pressure adjusting screw is rotated clockwise, the set value of the outlet pressure decreases, and when it is rotated counterclockwise, the set value of the outlet pressure increases.

4. The miniature piston-type high-pressure pressure reducing valve according to claim 1, characterized in that: It also includes a silencer located in the inner cavity, the silencer being located downstream of the inlet and fixed in the inner cavity of the valve body, and the sealing seat being adjacent to the downstream of the silencer.

5. The miniature piston-type high-pressure pressure reducing valve according to claim 4, characterized in that: It also includes a connecting seat, which has a cavity coaxial with the inlet. The silencer and the sealing seat are sequentially arranged in the connecting seat. The connecting seat is inserted into the inlet end of the valve body cavity and is fixed by a locking screw through the external thread of the connecting seat.

6. The miniature piston-type high-pressure pressure reducing valve according to claim 5, characterized in that: The silencer is a porous sintered metal structure and is fitted into the inlet flow channel of the valve body with a clearance fit; the silencer and the sealing seat are locked and fixed by the locking screw.

7. The miniature piston-type high-pressure pressure reducing valve according to claim 1, characterized in that: The sealing seat has an overall cylindrical structure, with an inner conical surface at one end near the valve stem forming a throttling orifice that matches the outer conical surface at the end of the valve stem.

8. The miniature piston-type high-pressure pressure reducing valve according to claim 1, characterized in that: The pressure relief seat is flat on one side facing the spring, and has an annular protrusion on the other side. The piston rod has a first step at the corresponding end. The first sealing ring is clamped in the annular cavity formed by the first step, the annular protrusion, and the inner wall of the valve body, which is coaxial with the piston rod.

9. The miniature piston-type high-pressure pressure reducing valve according to claim 1, characterized in that: The inner cavity wall is provided with an integral limiting step, the length direction of the limiting step extends to the reserved space, and the space between the sealing seat and the limiting step is formed for the piston to slide in the inner cavity; The piston rod is a hollow circular tube, which is arranged along the length of the limiting step. The sealing diameter of the piston is larger than the sealing diameter of the piston rod and the pressure relief seat. The reserved space provides movement space for the piston rod and is also the pressure-bearing space at the outlet. The valve stem is T-shaped in general. The head of the T-shape is fixed inside the hollow tube and close to the piston. The conical end of the T-shape is the outer conical surface. The rod extending from the conical end is a small-diameter section. The small-diameter section continues to extend to a large-diameter section. The large-diameter section extends to the head of the T-shape. The large-diameter section is located inside the hollow tube of the piston rod and there is the first gap between them.

10. The miniature piston-type high-pressure pressure reducing valve according to any one of claims 4-6, characterized in that: The muffler, sealing seat, piston, valve stem, piston rod, spring, pressure relief seat and first sealing ring are arranged sequentially along the same axis, wherein the sealing seat and the first sealing ring are made of PEEK material.

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