Multistage bypass control valve for automatic recirculation valve

Abstract

The present disclosure relates to an automatic recirculation valve assembly (10) designed to enhance the operational efficiency and reliability of centrifugal pump systems The valve assembly (10) comprises of two primary components: a main body (12) and a bypass body (14), which work together to optimize fluid management. The main body (12) houses a check valve assembly (16) oriented along a vertical axis (V), allowing unobstructed fluid flow and preventing backflow to maintain optimal pump conditions. Key components of the check valve assembly (16) include a top flange (20) for structural integrity and connection to the pumping system, and a main plug (22) that seals the assembly and regulates flow. The bypass body (14) contains a bypass valve assembly (18) aligned along a horizontal axis (H) to facilitate efficient bypass flow when needed. The valve assembly (18) includes a seat ring (24) for sealing, a liner (26) to minimize turbulence, a bypass plug (28) to control flow, a control head (30) to manage operational parameters in response to system demands, and a lever (32) for manual or automated control.

Description

[0001] Title: MULTISTAGE BYPASS CONTROL VALVE FOR AUTOMATIC RECIRCULATION VALVE

[0002] FIELD OF THE INVENTION

[0003] The present disclosure relates to automatic recirculation valve assembly. More particularly, the present disclosure relates to valve assemblies for bypass recirculation control in centrifugal pumping systems. In particularly, the present disclosure relates to a multistage bypass control valve for automatic recirculation valve.

[0004] BACKGROUND OF THE INVENTION

[0005] Centrifugal pumps are integral components in various industrial applications, designed to efficiently convert mechanical energy into pressure energy through the centrifugal force generated by an impeller's rotation. Such a process acts on the fluid within the pump, facilitating its movement. However, to maintain optimal performance and prevent overheating, it is crucial to sustain a minimum streamlined liquid flow. Failure to maintain such a predefined minimum flow can lead to malfunctioning of the pump, potentially resulting in permanent damage to the system.

[0006] To address the risks associated with overheating and cavitation, an automatic recirculation valve (ARV) is employed as a protective mechanism for centrifugal pumps. The ARV ensures that the required minimum flow is maintained, thereby safeguarding the pump from adverse operating conditions. The ARV comprises a combination of a check valve and a high-pressure drop bypass control valve, which are interconnected to form a cohesive unit. The operation of the ARV is inherently linked to the main line flow, allowing it to function autonomously without the need for external forces.

[0007] In certain applications, particularly those involving service process control characterized by high- pressure drops and elevated flow velocities, the ARV is critical. Cavitation, a phenomenon that occurs when local pressure drops lead to the formation of vapor bubbles, can severely impact the integrity of pump components. The high-velocity fluid particles resulting from cavitation can cause erosion and degradation of materials. To counteract these effects, the use of harder materials for the construction of pump components is a viable option, providing a degree of protection against erosion and extending the service life of the equipment. However, a need, therefore, still exists for an advanced solution that not only addresses the limitations of existing automatic recirculation valves but also effectively manages pressure drops and enhances fluid dynamics within centrifugal pumping systems to prevent overheating and cavitation, thereby improving overall pump reliability and efficiency.

[0008] SUMMARY AND OBJECTS OF THE INVENTION

[0009] One of the objects of the present disclosure is to address the significant need for improved fluid management within centrifugal pumping systems, thereby enhancing their reliability, efficiency, and longevity in various industrial applications.

[0010] Another object of the present disclosure is to provide an automatic recirculation valve assembly that enhances the operational efficiency and reliability of centrifugal pumps by ensuring the maintenance of minimum flow requirements, thereby preventing overheating and cavitation. By ensuring that the pump operates within its optimal parameters, the valve configuration helps protect critical components and extends the overall lifespan of the pumping system.

[0011] Another object of the present disclosure is to provide a valve configuration which enables dynamic operation of the automatic recirculation valve assembly in response to process flow demand. Such a dynamic responsiveness ensures that the pump consistently operates at peak efficiency, optimizing energy consumption and reducing maintenance requirements.

[0012] Another object of the present disclosure is to provide a multi-stage bypass valve design that allows effective pressure reduction and smooth fluid management through perforated liners and annular seat rings. By incorporating a perforated liner and a seat ring with annular spaces, the bypass valve assembly facilitates the passage of fluid through multiple stages, effectively reducing the fluid pressure to the desired output level. The advanced design contributes to improved fluid management within the centrifugal pumping system, enhancing overall reliability, efficiency, and longevity in various industrial applications. Accordingly, the present disclosure relates to an automatic recirculation valve assembly designed to enhance the operational efficiency and reliability of centrifugal pumps. The automatic recirculation valve (ARV) is installed on the pump discharge or as close as possible to the discharge point to ensure optimal performance. The ARV comprises a spring-loaded check valve assembly integrated into the main line, coupled with a specially engineered bypass control valve assembly situated in the recirculation line. Such a configuration, being essential for maintaining the minimum flow requirements of the pump, which further helps in preventing overheating and cavitation. The operation of the ARV is dynamically responsive to the process flow demand, ensuring that the pump operates within its optimal parameters.

[0013] In addition, the present disclosure relates to a novel design for the bypass valve assembly, which comprises a perforated liner and a seat ring featuring annular spaces. The bypass valve assembly facilitates the passage of fluid through multiple stages, thereby enhancing the efficiency of fluid flow management within the system. The perforated liner is designed to allow controlled distribution of fluid, ensuring that the fluid traverses through the various stages of the valve in a manner that effectively reduces the fluid pressure to a predetermined output level. By enabling this multi-stage fluid passage, the bypass valve assembly not only optimizes the pressure reduction process but also contributes to the improved overall performance and reliability of the centrifugal pumping system. The innovative design provides a significant advancement in bypass valve technology, addressing the critical need for efficient pressure management in industrial applications.

[0014] The present disclosure, thus, relates to an automatic recirculation valve assembly incorporating specially engineered trim components designed to enhance the operational efficiency and reliability of centrifugal pumping systems. The bypass side of the valve is engineered to handle high-pressure liquid flow, with fluid flow channels offering maximum resistance to the highly erosive flow conditions commonly encountered in industrial applications.

[0015] The bypass valve assembly is designed to reduce pressure and velocity by forcing the fluid through an array of holes and throttling stages allocated over successive stages of the valve trim. As the fluid passes through these multiple stages, its pressure drops significantly, effectively mitigating the risks associated with high-pressure drops and cavitation. Such a multi-stage pressure reduction process contributes to improved overall performance and reliability of the centrifugal pumping system.

[0016] The innovative design of the bypass valve assembly incorporates a perforated liner and a seat ring featuring annular spaces. Such a configuration facilitates the passage of fluid through multiple stages, enhancing the efficiency of fluid flow management within the system. The perforated liner allows for controlled distribution of fluid, ensuring that it traverses through the various stages of the valve in a manner that effectively reduces the fluid pressure to a predetermined output level.

[0017] By enabling such a multi-stage fluid passage, the bypass valve assembly optimizes the pressure reduction process, addressing the critical need for efficient pressure management in industrial applications. The specially engineered trim components and the innovative design of the bypass valve assembly represent a significant advancement in automatic recirculation valve technology, contributing to enhanced operational efficiency and reliability of centrifugal pumps.

[0018] BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0019] The above and other objects and advantages of the disclosure will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:

[0020] FIG. 1 illustrates a cross-sectional view of an automatic recirculation valve assembly which comprises a combination of two valves, a check valve assembly in the vertical axis and a bypass control valve assembly in the horizontal axis, in accordance with some examples of the present disclosure;

[0021] FIGS. 2A & 2B illustrate a side and a perspective view respectively of a seat ring of the bypass control valve assembly of Fig. 1 ;

[0022] FIGS. 3A & 3B illustrate a side and a perspective view respectively of a liner of the bypass control valve assembly of Fig. 1 ;

[0023] FIGS. 4A & 4B illustrate a side and a perspective view respectively of a bypass plug of the bypass control valve assembly of Fig. 1 ;

[0024] FIGS. 5A & 5B illustrate sectional views of the bypass control valve assembly showing the bypass plug closed and open positions respectively. DETAILED DESCRIPTION OF THE INVENTION

[0025] Fig. 1 illustrates an automatic recirculation valve assembly 10 according to the present disclosure, designed to optimize the operational efficiency and reliability of centrifugal pump systems. The valve assembly 10 comprises two valves, a check valve 16 in the vertical line and a bypass control valve 18 in the horizontal line which works in concert to facilitate effective fluid management within the system. The check valve assembly 16 includes main body 12, which is oriented along a vertical axis V to allow for unobstructed fluid flow and to prevent backflow, thereby ensuring that the centrifugal pump operates under optimal conditions. The check valve assembly 16 consists of several other components, including a top flange 20 that provides structural integrity and facilitates connection to the pumping system, and a main plug 22 that serves to seal the assembly 10 and regulate flow. In contrast, the bypass body 14 houses a bypass valve assembly 18, which is aligned along a horizontal axis H to enable efficient bypass flow when necessary. The bypass valve assembly 18 includes components such as a seat ring 24 that provides a sealing surface for the bypass valve, a liner 26 that creates resistance to the fluid flow by passing the flow through perforated holes, a bypass plug 28 that controls the flow through the bypass pathway, a control head 30 that manages the operational parameters of the bypass valve 18 in response to system demands, and a lever 32 that acts as a mechanical interface for manual or automated control. Collectively, these components of the automatic recirculation valve assembly 10 are engineered to enhance the performance and reliability of centrifugal pumping systems by preventing cavitation, maintaining optimal flow conditions, and ensuring seamless operation across varying system demands.

[0026] The main body 12 serves as the primary pressure-containing component of the automatic recirculation valve assembly 10, engineered to withstand the rigors of the pumping system's operating environment. The main body 12 has an upstream section. The upstream section of the main body 12 has an inlet section 12a with a bore that leads to an internal gallery 12b, providing a dedicated flow path for fluid entering the valve assembly 10. Within the gallery 12b of the main body 12, a check valve seat 12c is positioned to serve as the seating surface for the check valve mechanism. The main plug 22, being a critical component of the valve assembly 10, is positioned within the gallery 12b and functions to regulate fluid flow across the valve assembly 10. The main plug 22 which has two ends, includes a center bore 42, that facilitates the passage of fluid through the valve assembly 10 when the check valve is in the open position. The inlet section 12a of the main body 12 is designed with a circular cross-section, with the dimensions of the inlet section 12a adhering to the specifications outlined in the ASME B16.34 standard for pipe flanges and flanged fittings. The standardized design ensures compatibility with a wide range of pumping system configurations and facilitates ease of installation and maintenance. The robust construction of the main body 12, combined with its flow path design and adherence to industry standards, contributes to the overall reliability and performance of the automatic recirculation valve assembly 10 in centrifugal pumping applications.

[0027] The top flange 20 serves as another pressure-containing component of the automatic recirculation valve assembly 10, providing structural integrity and facilitating the connection of the valve to the pumping system. Centrally located within the top flange 20 is a guide bush 34, which functions as a positioning mechanism for the check valve assembly 16. Similar to the inlet section 12a of the main body 12, the top flange 20 comprises an outlet section 20a with a circular bore, the dimensions of which adhere to the specifications outlined in the ASME B16.34 standard. The standardized design ensures compatibility with a wide range of pumping system configurations and enables seamless integration of the valve assembly 10. The top flange 20 is precisely guided into the main body 12 and securely connected using one or more fasteners 36, such as nuts, bolts, washers or screws or the like. The placement of these fasteners 36 ensures a robust and reliable connection between the top flange 20 and the main body 12, withstanding the pressures and stresses encountered during operation. The faces of the inlet section 12a and outlet section 20a, containing the respective inlet and outlet bores of the main body 12 and the top flange 20, are separated by a distance equal to the end-to-end length of the check valve assembly 16. The precise spacing allows for the proper installation and operation of the check valve mechanism, ensuring that the valve can effectively regulate fluid flow and prevent backflow within the pumping system.

[0028] The main plug 22, which comprises two distinct ends, is positioned within the gallery 12b of the main body 12 and is securely seated on the designated seat surface of the check valve seat 12c formed in the main body 12. Such an arrangement ensures proper sealing and flow control within the valve assembly 10. One end of the main plug 22 is guided by the guide bush 34, which is integrated into the top flange 20, providing stability and alignment during operation. The opposing end of the main plug 22 is supported by a plug guide 38, which is located within the main body 12 to further enhance the guidance and stability of the plug 22 during its movement. The dualguidance system minimizes lateral movement and ensures that the main plug 22 operates smoothly and effectively within the valve assembly 10. Additionally, a compression spring 40 is housed within the center bore 42 of the main plug 22, providing a predetermined force that biases the plug 22 towards its closed position. The spring mechanism, being essential for maintaining the integrity of the check valve assembly 16, ensures that the main plug 22 returns to the closed position when fluid flow ceases, thereby preventing backflow and maintaining the operational efficiency of the centrifugal pumping system. The coordinated interaction between the main plug 22, the guide bush 34, the plug guide 38, and the compression spring 40 collectively contributes to the reliable and efficient performance of the automatic recirculation valve assembly 10.

[0029] The control head 30 of the bypass valve assembly 18 is positioned within a dedicated gallery 12d in the bypass side of the main body 12, which is adjoined to the bypass body 14, facilitating effective communication between the two assemblies. The control head 30 comprises two distinct ends, with one end connected to a lever 32 via a pivot pin 44. The lever 32 is in direct contact with the main plug 22, allowing for the transfer of the main plug's movement to the bypass valve assembly 18, thereby enabling coordinated operation between the check valve assembly 16 and the bypass valve assembly 18. The opposing end of the control head 30 is equipped with an annular face 30c that interfaces with a corresponding annular face 12e of the main body 12, ensuring a secure and stable connection. The control head 30 further comprises a plurality of perforated holes 30b machined into its annular face, which facilitate fluid flow and pressure equalization within the assembly 10, contributing to the overall responsiveness and efficiency of the bypass valve operation.

[0030] Internally, the control head 30 houses a balance bolt or contact button 46, along with a guide bush 48, both of which serve to guide the movement of the bypass plug 28. The bypass plug 28 is secured in place by a bypass plug end ring 50, ensuring that it remains properly aligned during operation. Additionally, the liner 26, having an inner wall 26b, is positioned within the seat ring 24, with both components being secured together by a pin 52 to prevent any undesired rotation of the liner 26 during operation. The liner and seat ring assembly rests firmly on an annular face 30a of the control head 30, providing a stable foundation for the bypass plug 28, which is completely guided by the inner walls 26b of the liner 26.

[0031] The bypass body 14 serves as another critical pressure-containing component of the automatic recirculation valve assembly 10, responsible for securely housing the entire bypass control mechanism and facilitating its integration with the main body 12. This integration is achieved through the use of one or more fasteners 36, such as nuts, bolts, washers or screws or the like, which firmly connect the bypass body 14 to the main body 12, ensuring a robust and reliable assembly. To optimize fluid flow and minimize turbulence within the bypass body 14, a flow straightener 54 is positioned inside the bypass body 14. The flow straightener 54 is designed to condition the fluid flow, reducing swirl and promoting a more uniform velocity profile, thereby enhancing the efficiency and performance of the bypass valve assembly 18. Furthermore, to prevent any undesired rotation of the bypass body 14 relative to the main body 12, an anti-rotation pin 56 is provided on the main body 12. The anti-rotation pin 56 is connected to both the control head 30 and the bypass body 14, effectively locking them in place and maintaining their relative orientation. Such an anti-rotation feature is crucial for ensuring consistent and reliable operation of the bypass valve assembly 18, as any rotational movement could potentially compromise the alignment and performance of the bypass valve components.

[0032] The bypass control valve assembly 18, as depicted in Fig. 1 , is engineered to precisely regulate the flow of recirculation fluid within the system, ensuring optimal performance and efficiency. To provide a comprehensive understanding of the assembly's components, reference is made to Figs. 2A and 2B, which illustrate the seat ring 24 of the bypass control valve assembly 18 from side and perspective views, respectively. The seat ring 24 plays a crucial role in providing a sealing surface for the bypass plug 28, facilitating effective closure and preventing fluid leakage when the valve 18 is in a closed position. Additionally, Figs. 3A and 3B depict the liner 26, which is integral to the bypass control valve assembly 18. The liner 26 is designed to absorb pressure drop across the bypass valve 18 by reducing the fluid pressure as it flows through perforated holes 26a1 ,26a2,26a3,26a4. The liner 26 also contributes to the overall stability of the bypass plug 28 during operation. Further, Figs. 4A and 4B depict the bypass plug 28, which acts as the primary flow control element within the bypass valve assembly 18. The bypass plug 28 is designed to move in response to pressure differentials and is guided by the liner 26 to ensure smooth operation.

[0033] To provide a more comprehensive understanding of the bypass control valve assembly 18, it is essential to note that this assembly comprises the seat ring 24, the liner 26, and the bypass plug 28, all of which are disposed within a designated gallery area 14a of the bypass body 14. The seat ring 24 and the liner 26 are configured as a subassembly, which is secured together by a pin 52 to prevent the liner 26 from rotating within the seat ring 24, thereby ensuring consistent alignment and functionality during operation. The liner 26 has a plurality of radial holes 26a1 to 26a4, which are arranged along its axis in a specific array to facilitate controlled fluid flow. As illustrated in Figs. 3A and 3B, the liner 26 is exemplified with at least four arrays of holes, although this configuration is not limited to this number.

[0034] The seat ring 24 further comprises inner walls 24b and outer walls 24c, with a side wall 24d that incorporates an orifice 24e to allow for fluid passage. Within the inner walls 24b of the seat ring 24, there are one or more annular spaces 24a1 to 24a4, which are defined by specific gaps. In the example depicted in Figs. 2A and 2B, the seat ring 24, not being limited to, contains at least four annular spaces within its inner walls 24b. This innovative design is engineered to direct the flow from the radial holes 26a1 to 26a4 in the liner 26 radially towards the corresponding annular spaces 24a1 to 24a4 in the seat ring 24. Specifically, the first set of holes 26a1 provided in the liner 26 is oriented towards the first annular space 24a1 , the second set of holes 26a2 of the liner 26 is directed towards the second annular space 24a2, and so forth. Such a configuration not only enhances the efficiency of fluid flow through the bypass control valve assembly 18 but also ensures that the fluid is evenly distributed across the various annular spaces, thereby optimizing the overall performance of the automatic recirculation valve assembly 10 in centrifugal pumping applications.

[0035] Further, as depicted in Fig. 1 , the seat ring 24 is positioned and rests on the annular face 30a of the control head 30, which is securely fastened between the bypass body 14 and the main body 12, ensuring a stable and leak-proof assembly. The bypass plug 28 is designed to move reciprocally within the inner wall 26b of the liner 26, comprises one or more distinct steps 28b along its outer surface as depicted in Figs. 4A & 4B. These steps 28b are equidistantly spaced and separated by annular spaces 28a1 to 28a4, which facilitate controlled fluid flow when the bypass plug 28 is in motion. One end of the bypass plug 28 is formed with a seat angle 28c, which is critical for sealing against the side wall 24d of the seat ring 24. The opposite end of the bypass plug 28 is guided within the bush 48, providing additional support and alignment during operation.

[0036] The design of the bypass valve assembly 18 allows for a fully closed configuration when the seat angle 28c of the bypass plug 28 makes contact with the side wall 24d of the seat ring 24, effectively preventing any fluid flow through the bypass valve assembly 18, as illustrated in Fig. 5A. Conversely, when the bypass plug 28 is retracted away from the side wall 24d of the seat ring 24, and the steps 28b of the bypass plug 28 align approximately at the center of the array of holes 26a1 to 26a4 in the liner 26 or the center of the annular spaces 24a1 to 24a4 in the seat ring 24, the bypass valve assembly 18 transitions to a fully open position, thereby allowing fluid to flow freely through the assembly 18, as depicted in Fig. 5B. Such a precise positioning of the bypass plug 28 ensures that it directly controls the volume of fluid that can pass through the bypass valve assembly 18, thereby regulating the recirculation flow and enhancing the overall efficiency of the automatic recirculation valve assembly 10 within centrifugal pumping applications. It is to be understood that the careful engineering of these components ensures reliable operation, adaptability to varying flow conditions, and optimal performance in diverse operational scenarios.

[0037] During the startup of the pump or in scenarios where there is no process demand, the bypass valve assembly 18 is configured to remain fully open, thereby facilitating the recirculation of the necessary minimum flow required for optimal operation. As process demand increases, the flow of fluid exerts a lifting force on the spring-loaded main plug 22, as illustrated in Fig. 1. This lifting action positions the main plug 22 according to the specific flow demand, allowing for dynamic adjustment of the valve assembly's operation. As the main plug 22 is lifted, the load is transmitted from the main plug 22 to the bypass lever 32, which subsequently engages the contact button 46. This engagement initiates a mechanical action that pushes against the guide bush 48.

[0038] The hydraulic load that acts in opposition to the guide bush 48 is effectively released due to the load transfer resulting from the movement of the main plug 22. This release allows the bypass plug 28 to disengage from the guide bush 48 and begin its movement toward the closing position of the bypass valve assembly 18. The modulation of the valve assembly 18 continues as long as the main flow demand remains within the established recommended minimum flow threshold. However, when the main flow demand exceeds this threshold, the main plug 22 reaches its maximum displacement. At this point, the bypass valve assembly 18 is fully closed, directing all fluid flow to the main line and effectively optimizing the system's performance by ensuring that the maximum flow is utilized for the intended process. Such a responsive and adaptive operation of the bypass valve assembly 18 helps in maintaining system efficiency, preventing cavitation, and ensuring that the centrifugal pumping system operates within its desired parameters under varying flow conditions.

[0039] When the bypass valve assembly 18 is in the closed position, as depicted in Fig. 5A, no fluid flow is permitted to pass through the assembly 18, effectively isolating the bypass circuit from the main flow path. By isolating the bypass circuit, the closed bypass valve assembly 18 ensures that all the fluid entering the main body 12 through the inlet section 12a is directed towards the main flow path, without any recirculation through the bypass. This configuration is typically employed when the main flow demand exceeds the recommended minimum flow, allowing the system to operate at maximum efficiency by directing the entire flow to the intended process.

[0040] Conversely, when the bypass valve assembly 18 is fully open, water from the inlet section 12a of the main body 12 is allowed to flow through the perforated holes 30b in the control head 30 into the annular space 28a1 located upstream of the bypass plug 28. From this initial point, the water enters the first set of holes 26a1 in the liner 26, which directs the flow into the first annular space 24a1 of the seat ring 24. At this juncture, the flow undergoes a directional change as it passes through the holes 26a1 in the liner 26, subsequently entering the second annular space 28a2 of the bypass plug 28. The water then continues its journey through the second set of holes 26a2 in the liner 26, allowing it to flow into the second annular space 24a2 of the seat ring 24. This process repeats as the flow turns again, passing through the holes 26a2 in the liner 26 into the third annular space 28a3 of the bypass plug 28. The water subsequently flows through the third set of holes 26a3 in the liner 26 into the third annular space 24a3 of the seat ring 24, following the same pattern of directional change.

[0041] Continuing this sequence, the flow then transitions through the holes 26a3 in the liner 26 into the fourth annular space 28a4 of the bypass plug 28. Finally, the water flows through the fourth set of holes 26a4 in the liner 26 into the fourth annular space 24a4 of the seat ring 24. After this last turn, the flow exits through the orifice 24e of the seat ring 24, entering the downstream side of the system. Before reaching the downstream components, the fluid passes through the flow straightener 54, which conditions the flow to reduce turbulence and promote a more uniform velocity profile. This carefully engineered flow path not only enhances the efficiency of the bypass valve assembly 18 but also ensures that the recirculation of fluid is managed effectively, contributing to the overall reliability and performance of the centrifugal pumping system.

[0042] For any position of the bypass plug 28 that falls between the fully closed and fully open configurations, the flow path through the bypass valve assembly 18 remains consistent; however, the flow rate is variable and directly influenced by the effective area of the sets of holes 26a1 to 26a4 in the liner 26. This effective area is modulated by the position of the bypass plug 28, which determines the degree to which each set of holes is exposed to the fluid flow. As fluid traverses through these sequential stages, first entering the annular spaces 24a1 to 24a4 of the seat ring 24 and subsequently passing through the corresponding holes in the liner 26, the flow encounters resistance, resulting in a pressure drop and a corresponding decrease in velocity. This dynamic interaction between the position of the bypass plug 28 and the resulting flow characteristics is essential for regulating the flow rate and achieving the desired pressure at the outlet of the valve assembly 10. By finely adjusting the position of the bypass plug 28, the system can effectively regulate the flow rate, allowing for optimal performance under varying operational conditions. Such a capability to control flow and pressure not only enhances the efficiency of the automatic recirculation valve assembly 10 but also ensures that the centrifugal pumping system operates within its intended parameters, thereby preventing issues such as cavitation and ensuring reliable system performance.

[0043] The bypass control valve technology of the present disclosure is fundamentally based on the principle of multi-step high resistance axial flow, which facilitates controlled pressure reduction along the length of the bypass plug 28. This innovative design incorporates a series of throttling stages, each engineered to evenly distribute the total pressure drop across multiple trim stages or steps. By ensuring that no individual stage is subjected to the full pressure differential, the design significantly enhances the longevity of the trim components, thereby extending their operational life. Furthermore, the fluid is directed through a tortuous flow path, which effectively reduces pressure in a staged manner while simultaneously introducing additional resistance and lowering the velocity head of the fluid. This carefully orchestrated flow dynamics not only minimizes pressure recovery but also mitigates the risk of vaporization occurring at the orifice. Consequently, the design effectively eliminates the potential for cavitation and the associated operational challenges, thereby ensuring reliable performance and improved efficiency of the bypass valve assembly 18. The above approach, thus, provides a significant advancement in valve technology, providing enhanced durability and operational stability in demanding fluid handling applications.

[0044] As used herein, the terms "proximal," "bottom," "down," or "lower" refer to a location on the bypass control valve assembly 18 that is closest to the operator or technician interacting with the device and farthest from the fluid source or downstream system to which the valve is connected during normal operation. Conversely, the terms "distal," "top," "up," or "upper" indicate a location on the assembly that is farthest from the operator and closest to the fluid source or downstream system during standard use.

[0045] The terminology used herein is for the purpose of describing particular embodiments, examples only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and / or" includes any and all combinations of one or more of the associated' listed items.

[0046] It can be further understood that the terms "comprises" "comprising," "includes" and / or "including", “contains” and / or “containing” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this present disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. The descriptions provided above represent example implementations of the present application and are not intended to limit the scope of protection afforded by this application. A person of ordinary skill in the art may identify substantially equivalent structures or actions that achieve similar results, either in the same manner or through alternative approaches. Therefore, the exemplary embodiments and examples discussed herein should not be construed as limiting the disclosure to a single embodiment. Instead, they serve to illustrate the versatility and adaptability of the bypass control valve assembly 18 and its components, highlighting the potential for various configurations and applications within the broader context of fluid management systems.

[0047] The present disclosure is not limited to the precise construction and compositions explicitly described herein. Any and all apparent modifications, changes, and variations stemming from the foregoing descriptions fall within the spirit and scope of this disclosure and are encompassed by the claims. Moreover, the present concepts expressly include any and all combinations and subcombinations of the preceding elements and features. The description is provided for clarification purposes and is not intended to be limiting. Words and phrases are to be accorded their ordinary, plain meaning unless indicated otherwise. In addition, while various features and components have been disclosed in an exemplary fashion, various other features and components may be employed. It is intended by the foregoing to cover these and any other departures from these disclosed embodiments which fall within the true spirit of this invention.

[0048] Thus, it is intended that the scope of the present invention herein disclosed should not be limited by disclosed embodiments described above but should be determined only by a fair reading of the appended claims.

Claims

CLAIMS1. An automatic recirculation valve assembly (10) for a centrifugal pump system comprising: a main body (12) oriented along a vertical axis (V) and having an inlet section (12a) with a bore leading to an internal gallery (12b) with a check valve seat (12c); a check valve assembly (16) including a spring-biased main plug (22) disposed in the gallery (12b) and configured to seat on the checkvalve seat (12c) to prevent backflow; a top flange (20) coupled to the main body (12) and guiding one end of the main Plug (22); a bypass body (14) joined to the main body (12) and housing a bypass valve assembly (18) aligned along a horizontal axis (H).

2. The automatic recirculation valve assembly (10) as claimed in claim 1 , wherein the bypass valve assembly (18) comprising: a control head (30) with an annular face (30c) and perforated holes (30b); a seat ring (24) having inner walls (24b) with a side wall (24d) including an orifice (24e); a liner (26) disposed within the seat ring (24) and having plural arrays of perforated radial holes (26a1, 26a2, 26a3, 26a4); a bypass plug (28) having multiple outer steps (28b) separated by annular spaces (28a1 to 28a4) and a seat angle (28c) at one end; a lever (32) operatively coupling motion of the main plug (22) to the bypass plug (28) via the control head (30).

3. The automatic recirculation valve assembly (10) as claimed in claim 2, wherein reciprocal motion of the main plug (22) in response to mainline flow modulates the bypass plug (28) between a closed position in which the seat angle (28c) seals against the seat ring (24) side wall (24d) to block bypass flow and an open position in which the steps (28b) align to expose effective areas of the liner hole arrays (26a1 to 26a4) to establish a multi-stage, high-resistance axial flow path from the inlet (12a) through the control head(30), liner holes(26a1 to 26a4), seat ring annular spaces (24a1 to 24a4), and the seat ring orifice (24e), thereby regulating recirculation flow.

4. The automatic recirculation valve assembly (10) as claimed in claim 1 , wherein the inlet section (12a) of the main body (12) and an outlet section (20a) in the top flange (20) each includes a circular bore to facilitate standardized piping connections.

5. The automatic recirculation valve assembly (10) as claimed in claim 1 , wherein the top flange (20) includes a guide bush (34) that constrains one end of the main plug (22), and the main body (12) includes a plug guide (38) that constrains an opposite end of the main plug (22) to minimize lateral movement during operation.

6. The automatic recirculation valve assembly (10) as claimed in claim 1 , wherein the main plug (22) includes a center bore (42) housing a compression spring (40) biasing the main plug (22) toward a closed position against the check valve seat (12c).

7. The automatic recirculation valve assembly (10) as claimed in claim 1 , wherein the bypass body (14) is fastened to the main body (12) with mechanical fasteners (36) and includes a flow straightener (54) downstream of the seat ring (24) orifice (24e) to condition flow and reduce turbulence.

8. The automatic recirculation valve assembly (10) as claimed in claim 1 , further comprising an anti-rotation pin (56) on the main body (12) engages the control head (30) and the bypass body (14) to prevent rotational misalignment of the bypass valve assembly (18).

9. The automatic recirculation valve assembly (10) as claimed in claim 2, wherein the control head (30) includes perforated holes (30b) in its annular face (30c) for pressure equalization and fluid communication to an upstream annular space adjacent the bypass plug (28).

10. The automatic recirculation valve assembly (10) as claimed in claim 2, wherein the liner (26) includes at plurality of axially spaced arrays of radial holes (26a1 to 26a4) and the seat ring (24) defines a corresponding plurality of annular spaces (24a1 to 24a4) within its inner walls (24b) aligned with a respective arrays of the liner holes (26a1 to 26a4).

11. The automatic recirculation valve assembly (10) as claimed in claim 10, wherein the liner (26) is pinned to the seat ring (24) to prevent liner rotation relative to the seat ring (24).

12. The automatic recirculation valve assembly (10) as claimed in claim 2, wherein the bypass plug (28) includes multiple equidistant steps (28b) defining annular spaces (28a1 to 28a4) that, when the bypass plug (28) is retracted, align substantially with centers of the liner hole arrays (26a1 to 26a4) or with centers of the seat ring (24) annular spaces (24a1 to 24a4) to establish a fully open bypass path.

13. The automatic recirculation valve assembly (10) as claimed in claim 1 , wherein the bypass plug (28) is positioned to fully open the bypass path to recirculate a minimum flow, and increasing process demand lifts the spring-biased main plug (22) to progressively close the bypass until a threshold main-line flow fully closes the bypass.

14. The automatic recirculation valve assembly (10) as claimed in claim 3, wherein the multi-stage axial bypass path provides distributed throttling across plural trim stages.

15. The automatic recirculation valve assembly (10) as claimed in claim 3, wherein intermediate positions of the bypass plug (28) between the closed and open positions modulate the effective flow area presented by the liner hole arrays (26a1 to 26a4) to control bypass flow rate and outlet pressure.

16. A method of regulating minimum flow in a centrifugal pump system using the automatic recirculation valve assembly as claimed in claim 1 , the method comprising: biasing the main plug closed with a compression spring;lifting the main plug in response to main-line flow to transmit load via a lever to a control head; relieving an opposing hydraulic load at a guide bush of the control head to permit the bypass plug to travel toward the closed position; progressively aligning the steps of the bypass plug with the arrays of liner holes to adjust effective flow area and distribute pressure drop across multiple stages until a threshold mainline flow fully closes the bypass path.

17. The method as claimed in claim 16, further comprising conditioning bypass outflow with the flow straightener downstream of an orifice of the seat ring to reduce turbulence before discharge.

18. The method as claimed in claim 16, wherein modulation of the bypass plug continues while mainline flow remains at or below a recommended minimum flow threshold and terminates in full bypass closure when the main plug reaches maximum displacement corresponding to a pre-set process demand.

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