System and method for automatically energizing packing material using a packing load assembly - Patents.com

Abstract

A pressure regulation system (10) for use with a fixture for applying a substantially uniform force or load to a set of stacked packing elements (110). The force applied to the packing elements (110) can be adjusted or controlled in real time and remotely. The seal includes an axially movable follower element (70) that can be biased by pressurized fluid to move between a preload position in which the follower element (70) applies no axial load to the packing elements (110) and a loaded position in which the follower element (70) applies an axial load to the packing elements (110). [Representative diagram] Figure 3

Description

[Technical field]

[0001] Related Applications This patent application claims priority to U.S. Provisional Patent Application No. 62 / 835,966, filed April 18, 2019, entitled "METHOD AND SYSTEM FOR AUTOMATICALLY ENERGIZING PACKING MATERIAL IN A MECHANICAL SEAL," the contents of which are incorporated herein by reference. [Background technology]

[0002] The present invention relates to packing material in fasteners, and more particularly to a system and method for automatically energizing packing material by applying a controllable axial load.

[0003] In some mechanical fields, it is necessary to provide a fluid-tight seal between adjacent pieces of equipment. For example, one common application of sealing technology involves a rotating shaft with fluid present at one end. In such situations, it may be desirable to prevent the fluid from leaking around the shaft. Thus, as is known, a stuffing box may surround the shaft. The stuffing box may include a packing material, often referred to as a compression packing seal, that is wrapped around the rotating shaft and provides the interface and sealing surface between the rotating shaft and the stuffing box. A compression packing seal typically consists of a series of stacked, axially abutting packing rings. A mechanical seal may be installed in place of the packing material in the stuffing box to aid in the shaft seal, or the packing material may be incorporated into the mechanical seal.

[0004] The compression packing seal may be a braided material that is typically square or circular in cross section, although the compression packing seal may be of various cross-sectional shapes. The compression packing seal may be cut to size and wrapped around the shaft to form an annular shape. Multiple rings may be provided along the length of the shaft to provide a seal around the shaft. The compression packing seal may be fixed and compressed within the stuffing box using a suitable structure, such as a gland. As the packing material is compressed, it expands radially to form a seal between the rotating shaft and the stationary stuffing box. The seal formed by the packing components forms a fluid seal and maintains a pressure boundary between the fluid within the stuffing box and the outside air.

[0005] A drawback of conventional packing installation techniques is that the packing's sealing ability deteriorates over time, so the packing must be continually compressed to maintain a fluid seal.

[0006] To solve this problem, conventional systems apply an axial force to the packing material to create and maintain a fluid seal between the stuffing box and the shaft. In one prior art system, a known structure such as a gland bolt can be used to apply an axial load force to the packing material. However, as the packing material wears over time, the axial load on the packing material decreases and leakage occurs, requiring periodic adjustment of the gland bolt. In another prior art system, a Belleville or conical washer can be used to apply an axial load to the packing material. However, as the spring stretches and the axial travel of the spring is restricted, the axial load decreases. Summary of the Invention

[0007] It is an object of the present invention to provide a shaft seal arrangement which maintains the sealing performance of the gland packing over time without requiring frequent adjustment or tightening of the seals. It is another object of the present invention to provide a remotely adjustable means for applying a substantially uniform and precise axial load to the packing material which compensates for wear of the packing material over time.

[0008] The present invention relates to a pressure regulation system for use with a packing load assembly and a locking device for applying a substantially uniform force or load to a set of stacked packing elements. The force applied to the packing elements can be adjusted or controlled in real time and remotely. The packing load assembly can include a gland and an axially movable follower element, which can be biased by a pressurized fluid to move between a preload position in which the follower element does not apply an axial load to the packing element, and a loaded position in which the follower element applies an axial load to the packing element. The axial load biases the packing element to form a fluid tight seal between a shaft and the packing element, and between the packing element and a selected surface of the locking device.

[0009] According to one aspect of the invention, the invention relates to a pressure regulation system for a stationary apparatus using a set of stacked packing elements, the pressure regulation system including a fluid source providing a source of fluid, a pressure regulator for regulating a pressure of the fluid to form a pressurized fluid, and a packing load assembly for sealing a process fluid within the stationary apparatus, the packing load assembly for applying an axial load force from the pressure regulator to the packing elements via the pressurized fluid, the pressure regulator including an inlet for receiving the fluid from the fluid source and an outlet for supplying the pressurized fluid.

[0010] The pressure regulation system may further include a fluid regulator disposed between the fluid source and the pressure regulator to regulate the flow of the fluid therebetween. The fluid regulator may be a check valve.

[0011] The packing load assembly may include an axially movable follower element and a gland for receiving the follower element. The gland includes a body having a top surface, an opposing bottom surface, and a side surface, a plurality of fastener receiving openings formed in the body for receiving fastener elements, a gland channel formed in the bottom surface of the body forming a gland pressure chamber, and a fluid supply port formed in the side surface and in fluid communication with the gland channel. The gland channel includes a bottom wall surface, first and second opposing side wall surfaces, and a sealing channel formed in each of the first and second opposing side wall surfaces for receiving a sealing element. The follower element includes a first end having a bucket-like structure and an opposing second end having a stem-like structure, the bucket-like structure including a U-shaped body having first and second opposing side walls and a bottom wall forming a pressure chamber. The stem-like structure has a foot at a distal end for contacting an axially outermost one of the plurality of packing elements.

[0012] The bucket-like structure is sized and configured to be at least partially received within the gland channel of the gland. Additionally, the follower element is movable between a first preload position in which the follower element is disposed at an axially outermost position and a second loaded position in which the follower element is moved axially inwardly such that the foot of the follower element contacts and applies a load force to the axially outermost one of the plurality of packing elements.

[0013] According to another aspect, the gland channel of the gland has opposing sidewalls spaced radially from one another and connected by a bottom wall, and the movable follower element is movable between a first preloaded position in which the bucket-like structure of the follower element is disposed within the gland channel and an upper surface of the bucket-like structure contacts the bottom surface of the gland channel, and a second loaded position in which the follower element moves axially inwardly and the upper surface of the bucket-like structure separates axially from the bottom wall surface of the gland channel. The gland pressure chamber of the gland and the pressure chamber of the follower element cooperatively define a pressurized chamber for selectively moving the follower element axially as a function of the pressure of the fluid in the pressurized chamber.

[0014] The system may further include an electronic device for communicating with and controlling the pressure regulator, the electronic device controlling the pressure of the pressurized fluid exiting the outlet and being delivered to the packing load assembly.

[0015] In another aspect, the invention relates to a packing load assembly for mounting to a fastener using a set of stacked packing elements, the packing load assembly including a gland and a follower element. The gland includes a body having a top surface, an opposing bottom surface, and a side surface, a plurality of fastener receiving openings formed in the body for receiving fastener elements, a gland channel formed in the bottom surface of the body forming a gland pressure chamber, and a fluid supply port formed in the side surface and in fluid communication with the channel. The follower element has a first end having a bucket-like structure with a generally U-shaped body having first and second opposing side walls and a bottom wall forming a chamber, and an opposing second end having a stem-like structure having a foot at its distal end for contacting an axially outermost one of the plurality of packing elements.

[0016] The gland pressure chamber and the chamber of the bucket-like structure are fluidly coupled to form a pressurized chamber for axially moving the follower element between a first preload position and a second loaded position. Additionally, the gland channel has first and second radially spaced apart wall surfaces and a bottom wall surface connected to the first and second wall surfaces. When the follower element is disposed in the first preload position, the bucket-like structure is disposed within the gland channel and an upper surface of the bucket-like structure contacts the bottom wall surface of the gland channel. When the follower element is disposed in the second loaded position, the upper surface of the bucket-like structure is radially separated from the bottom wall surface of the gland channel. [Brief description of the drawings]

[0017] These and other features and advantages of the present invention will become more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which like reference characters indicate like parts throughout the several views, which illustrate the principles of the invention and, although not to scale, show relative dimensions. [Figure 1] FIG. 1 is a schematic block diagram of a pressure regulation system that uses a packing load assembly in accordance with the teachings of the present invention. [Diagram 2] FIG. 2 is a perspective view of a packing load assembly for use with the pressure regulating system of FIG. 1 in accordance with the teachings of the present invention. [Diagram 3] FIG. 3 is a cross-sectional view of a packing load assembly showing a movable follower element disposed in a preload position in accordance with the teachings of the present invention. [Figure 4] FIG. 4 is a cross-sectional view of a packing load assembly showing the moveable follower element in a loaded position in accordance with the teachings of the present invention. [Diagram 5] FIG. 5 is a cross-sectional view of a follower element of a packing load assembly in accordance with the teachings of the present invention. [Figure 6] FIG. 6 is a schematic diagram of a compact built-in housing. BEST MODE FOR CARRYING OUT THEINVENTION

[0018] The present invention relates to a pressure regulation system used in conjunction with a packing loading assembly to apply an axial load force to packing material contained within a fixture in an automated manner. The pressure regulation system may be used to apply an axial fluid force to a follower element which in turn applies an axial load force to the packing material, thereby controlling or adjusting the axial force. Those skilled in the art will readily appreciate that the present invention may be implemented in many different applications and embodiments and is not specifically limited to the specific embodiments described herein.

[0019] As used herein, the term "shaft" is intended to refer to any suitable device in a mechanical system to which a seal can be attached, including shafts, rods, and other known devices.

[0020] As used herein, the terms "axial" and "axially" refer to directions generally parallel to the axis of any shaft. As used herein, the terms "radial" and "radially" refer to directions generally perpendicular to the axis of any shaft. The terms "fluid" and "fluids" refer to liquids, gases, and combinations thereof.

[0021] The term "axially inboard" as used herein refers to portions of the stationary equipment and / or components of the mechanical seal that are proximate to the stationary equipment (e.g., mechanical system) in which the mechanical seal is used. Thus, the term refers to components of the mechanical seal or packing load assembly that are mounted on or within the stationary equipment or that are located deep or closest to the interior of the equipment (inboard). Conversely, the term "axially outboard" as used herein refers to portions of the stationary equipment and mechanical seal or packing load assembly that are distal to the equipment (outboard).

[0022] As used herein, the term "radially inner" refers to that portion of a mechanical seal, packing load assembly, or associated component that is proximate to any shaft, and conversely, the term "radially outer" refers to that portion of a mechanical seal, packing load assembly, or associated component that is disposed distally from the shaft.

[0023] As used herein, the terms "stationary device," "stuffing box," and / or "stationary surface" are intended to include any suitable stationary structure that accommodates a shaft or rod to which a mechanical seal or packing load assembly with a gland is secured. The stationary structure may include any type of commercial or industrial device, such as a pump, valve, etc. A person of ordinary skill in the art will also appreciate that the gland assembly may form part of the mechanical seal, packing load assembly, or stationary device.

[0024] As used herein, the terms "process medium" and / or "process fluid" generally refer to the medium or fluid being transported through a stationary apparatus. In a pump application, for example, the process medium is the fluid being pumped through the pump housing.

[0025] As used herein, the term "gland" is intended to include any suitable structure that enables, facilitates, or assists in the fastening of a mechanical seal or packing load assembly to a fastening device, while at least partially surrounding or containing one or more seal components. If desired, the gland may also provide fluid access to the mechanical seal.

[0026] As used herein, the term "mechanical seal" is intended to include any of a variety of sealing structures used to seal a process fluid between a moving (e.g., rotating) component and a stationary component of a stationary device, including, for example, single seals, split seals, tandem seals, double seals, concentric seals, gas seals, spiral seals, and other known seal types and configurations.

[0027] As used herein, "packing material" is intended to include resilient, at least partially compressible materials for sealing against various fluids within a gland or fastener over a wide range of pressures and temperatures.

[0028] As used herein, the term "packing load assembly" is intended to include any selected component or assembly of components, including at least a gland, for example, for applying an axial load pressure to a packing material to provide a seal between at least a stationary component and a movable component of a stationary device.

[0029] The terms "ambient environment" or "ambient pressure" are intended to include an external environment or pressure other than the internal environment of a gland, packing load assembly, mechanical seal, or fixture.

[0030] The present invention relates to a packing load assembly having a gland with a sealed cavity therein that houses a piston load follower element that acts on the packing material. The piston load follower element is actuated by one or more externally regulated or controlled pressure sources that apply a pressurized fluid or medium, such as, for example, compressed air in the workshop or a suitable water supply. A pressure regulator can be used to help regulate, vary or control the pressure in the gland, thereby applying a generally or substantially constant or uniform axial load force to the packing material. As the packing material relaxes over time due to wear, thermal cycling, vibration, pressure surges, etc., the pressure fluid can be controlled, regulated or varied to help maintain a generally or substantially constant or uniform load on the packing material. The use of a fluid regulating element, such as a check valve in the supply line to the pressure regulator, allows the load on the packing material to be maintained even if the supply of pressurized fluid is momentarily stopped. A supply of pressurized fluid is typically available in industrial and commercial plants. The desired load can be set remotely at a convenient location away from the rotating machine component, such as a shaft.

[0031] The present invention relates to an improved live pressure load packing loading assembly or system concept that automatically energizes the packing material in a stationary device to compensate for packing compression and wear over time. The present invention also allows for packing adjustments away from the rotating machine parts. Once the packing material is installed and axially loaded with the proper compression, the radial pressure on the packing must be equal to or greater than the pump process fluid pressure at the wet end to provide a proper and sufficient seal. Packing material relaxation behavior can be caused by wear, thermal cycling, vibration, pressure surges, etc.

[0032] A structural component, such as a piston-loaded follower element, can be configured to provide a hydraulic or pneumatic axial load to the packing material when installed within the fixture to limit or prevent fluid leakage therefrom and form a positive seal with process fluid pressure from an equipment such as a pump. The gland component can be secured to a housing of the fixture and preferably houses the follower element.

[0033] FIG. 1 illustrates a pressure regulation system 10 of the present invention. The pressure regulation system 10 includes a pressurized fluid source 12 for containing and supplying pressurized fluid to a packing load assembly 18. The fluid may be a gas, such as air or nitrogen, or a liquid, such as water. The fluid source 12 is coupled to a pressure regulator 16 through a fluid conditioning device 14 via suitable piping or mechanical connections. The pressure regulator 16 may be any suitable structure or device for regulating or controlling the pressure of a fluid to a desired value. The pressure regulator 16 has a fluid inlet 16A for receiving fluid from the fluid source 12 and a fluid outlet 16B for delivering outlet fluid to the packing load assembly 18. Fluid from the pressurized fluid source enters the fluid inlet 16A at a first, higher pressure and typically exits the pressure regulator at the fluid outlet 16B at a second pressure, which may be less than or substantially equal to the inlet pressure. The pressure regulator 16 may include a mechanical structure, such as a pressure setting or adjusting element 16C (FIG. 5), which may include a spring, coupled to a sensor, such as a diaphragm or bellows, as known in the art. The sensor may be configured to sense or detect the pressure of the fluid at the outlet. The sensor may also be coupled to a restrictor element, such as a valve seat, which may be moved axially to control, adjust, or vary the amount of fluid exiting the regulator, thereby controlling the pressure of the fluid at the outlet. The pressure regulator may use feedback of the regulated pressure as an input to a setting or control mechanism for the regulator, which may control the opening of the restrictor element in response to changes in the feedback pressure. The structure and operation of pressure regulators are well known in the art and need not be described further herein.

[0034] The fluid regulation device 14 serves to control or regulate the flow of fluid between the fluid source 12 and the fluid regulator 16. According to one embodiment, the fluid regulation device 14 may be a check valve that serves to prevent the loss of fluid back through the pressure regulator 16 in the event that the fluid source 12 is unable to provide the input fluid and corresponding pressure to the inlet of the pressure regulator 16. That is, a check valve may be used in the supply line to the pressure regulator 16 to maintain the load on the packing material even if the supply of pressurized fluid is momentarily or sustainedly stopped. The structure and operation of check valves are well known in the art and need not be described further herein. The pressure regulation system may also employ one or more pressure sensors or detectors, such as, for example, pressure gauges, to measure the pressure of the fluid in the system at selected locations. The pressure sensors may be located at any selected location, such as on either side of the pressure regulator 16 or between the pressure regulator and the packing load assembly 18.

[0035] The pressure regulator 16 and / or the packing load assembly 18 may optionally communicate with the electronic device 22 directly or through a network 20. The pressure regulator and the packing load assembly may communicate directly with the electronic device 22 through any suitable wireless connection, such as a WiFi or Bluetooth connection. Alternatively, these devices may communicate with the electronic device 22 through a standard network 20. As is known, the network 20 may include one or more electronic devices, such as a server or a computer. These servers may include suitable processors, storage, and memory, as known in the art. Additionally, suitable operating software may be stored on the storage device to operate and control the server and, if desired, one or more elements of the pressure regulation system 10. The electronic device 22 may be any suitable device, such as a server, computer, tablet, smartphone, etc. Additionally, like the servers of the network 20, the electronic device may include known hardware, such as one or more processors, memory, storage, and other structures, such as, for example, an input device (e.g., a mouse and / or keyboard) and a display. Suitable system software may be stored on either or both of network 20 and electronic device 22 to control and operate one or more elements of pressure regulation system 10 .

[0036] 2-5 illustrate the features and elements of the packing load assembly 18 of the present invention. The packing load assembly 18 may include a gland element 30 coupled to a retainer 50 by a series of fastener elements 90. The retainer 50 may include, for example, a pump housing having a rotating shaft 28 extending outwardly therefrom and containing a process fluid that needs to be sealed within the pump housing. The retainer 50 may include a body 52 with a fastener receiving opening 54 formed therein. The body 52 also has a radially inner channel 56 formed therein having a bottom or flange portion 58 and an axially extending wall surface 60. The channel 56 contains a packing material, such as a series of annular packing elements 110 that form a seal between the shaft 28 and the body 52 of the retainer 50 to seal the process fluid therein. The channel may also contain one or more bushings or bearing elements, if desired or necessary, to help prevent one or more of the packing elements 110 from being inadvertently pushed out of the channel 56. Thus, in operation, the packing elements 110 help to form a seal between them and the shaft 28, and between them and the surface of the channel 56. The body of the fastener 50 has a top surface 52A and an opposing bottom surface 52B. The bottom surface 52B defines a channel 62 for receiving the sealing element. Those skilled in the art will readily recognize that the fastener housing can have any selected configuration, and that the configuration depicted herein is for illustrative purposes.

[0037] The packing load assembly 18 may include a gland element 30 and a follower element 70, which may be preassembled to the cartridge or may be separate attachable elements or components. The gland element 30 includes a body 32 having opposing top and bottom surfaces 32A, 32B, respectively, and a side or circumferential surface 32C. The top surface 32A defines a plurality of fastener receiving openings 34 for receiving a fastener assembly including a fastener element 90. The fastener element 90 may be a bolt-like element that mates with a jam nut 92 at an axially inner end and a washer 94 and a nut 96 at an axially outer end. Similarly, the top surface 32A of the body 32 of the gland 30 may include a plurality of centering openings 36 for receiving centering elements, such as a centering button 114. The centering button 114 serves to center the gland 30 relative to the shaft 28 during installation, as is known in the art. The bottom surface 32B of the gland 30 also includes an annular channel 40 that forms an annular chamber.

[0038] The side 32C of the gland 30 may include one or more fluid supply ports 38 for supplying pressurized fluid to the packing load assembly 18 for applying pressure to the packing element 110 through the follower element 70. The fluid supply port 38 may include a first wide port portion 38A for coupling to any selected fluid connection element, such as a pipe. The fluid supply port 38 includes a second radially extending portion 38B and a third axially extending portion 38C in communication with the channel 40. A pair of opposing channels 42 and 44 are formed on the sides of the channel 40 for receiving the sealing elements 46 and 48, respectively. The sealing elements 46 and 48 form a fluid tight seal with the follower element 70. The fluid supply port 38 may be formed on other surfaces of the gland 30, if desired. One skilled in the art will readily recognize that the gland may have any selected shape or configuration, and the configuration currently shown is for illustrative purposes.

[0039] The follower element 70 is axially movable and sized and configured to apply an axial load or force to the packing element 110 when properly pressurized by fluid applied through the fluid supply port 38. The follower element 70 is movable between a preload position ( FIG. 3 ) and a loaded position ( FIG. 4 ). In the preload position, the follower element 70 contacts or is slightly separated from the packing element 110 but does not properly or sufficiently apply a load or axial force. When pressurized fluid is applied to the fluid supply port 38, the follower element 70 moves from the preload position to the loaded position and applies an axial force or load to the packing element to seal the process fluid within the fixture 50.

[0040] As shown in Figures 3-5, and in particular in Figure 5, the follower element 70 includes a body portion 72 having a first axial end with a bucket-like structure 74 and an opposing second end with a stem-like structure 75 with a foot portion 76. The bucket-like structure 74 has a body having a U-shaped bucket structure that defines a chamber 78 that connects and cooperates with the channel 40 to form a pressurized chamber for axially moving the follower element 70. The bucket structure 74 has a pair of radially spaced opposed walls 74A and 74B connected by a bottom wall 74C. The walls 74A, 74B, and 74C have inner and outer surfaces. The stem-like structure has a body having a substantially elongated, narrow stem-like shape terminating at its distal end with a foot portion 76. The foot 76 has a greater radial planar area than the stem-like structure 74 and is configured to contact the axially outermost packing element 110 and exert an axially inward force to axially load the packing element 110. One skilled in the art will readily appreciate that the follower elements can have any selected configuration and that the configuration currently shown is for illustrative purposes.

[0041] The pressure regulation system 10 includes a pressure regulation subassembly 130 that includes selected elements of the pressure regulation system, which may include, for example, at least a fluid source and a pressure regulator. FIG. 6 illustrates one embodiment of a self-contained pressure regulation subsystem 130 suitable for use with the packing load assembly 18 according to the teachings of the present invention. As illustrated, the pressure regulation subsystem 130 may include a housing 132 that may have any selected shape or size, and is preferably formed as an enclosure. The enclosure may have any suitable cover element, such as a door (not shown), if desired. The pressure regulation subsystem 130 may be mounted within the housing 132. The illustrated pressure regulation subsystem 130 may include a self-contained pressurized fluid source 134 that may be connected to the pressure regulator 16 by a suitable fluid conduit, such as piping. The fluid source 134 may be the same as or similar to the fluid source 12. The pressure regulator 16 may include a pressure setting element 16C for setting a pressure level of the fluid at the outlet 16B of the pressure regulator. If desired, a fluid regulation element, such as a check valve (not shown), may also be included in this subsystem. As illustrated, one or more optional pressure sensors, such as a pressure gauge 138, may be used to detect or sense pressure at selected locations in the pressure regulation subsystem 130.

[0042] The illustrated pressure regulation subsystem 130 may also include an optional pressure intensifier 140. The pressure intensifier 140 may be used to increase the pressure of the fluid exiting the pressure regulator to a high level suitable for use in the packing load assembly 18. Specifically, the pressure intensifier 140 has a fluid inlet 140A and a fluid outlet 140B. Fluid enters the intensifier at the fluid inlet 140A at a first pressure level and exits at the fluid outlet 140B at a second, higher pressure level. As is known in the art, the pressure intensifier 140 may be configured to achieve a predetermined pressure increase. Thus, the pressure intensifier may be selected to provide sufficient pressurized fluid at the fluid outlet 140B to apply an axial load to the packing element 110. The pressurized fluid 142 exiting the pressure regulation subsystem 130 is then conveyed to the packing load assembly 18 to bias the packing element 110.

[0043] In operation, the pressure regulation system 10 of the present invention may function and operate as follows: The packing load assembly 18 of the present invention may be mounted to a fixture 50 including a stuffing box or shaft 28. A series of stacked packing elements 110 are mounted within a channel 56 of the fixture 50. The packing load assembly 18 includes a gland 30 and a follower element 70. The gland 30 is then coupled to the fixture 50. Specifically, the foot 76 of the follower element is positioned adjacent to and in contact with the axially outermost packing element 110. The bucket-like structure 74 of the follower element 70 is received within the channel 40 of the gland 30. The gland 30 is secured to the fixture 50 by a fastener assembly including a fastener element 90, a jam nut 92, a washer 94, and a nut 96. A centering device 114 may be used to center the packing load assembly 18 around the shaft 28. The packing load assembly can also use a clip element (not shown) which can have a select portion received between the follower element and the upper surface of the fastener to hold the follower element in a preloaded position during assembly and prior to operation, if desired.

[0044] The gland 30 includes a body 32 having a channel 40 formed in a lower or bottom surface 32B for receiving an upper bucket-like portion of a follower element 70. The gland 30 also has a fluid supply port 38 formed in a side surface 32C thereof in communication with the channel 40. Additional sealing elements, such as O-rings, may be used to help seal the pressurized fluid within the packing load assembly. The follower element 70 has an upper portion including a bucket-like structure 74 forming a chamber 78 disposed within the channel 40 formed in the gland 30, and an opposing lower portion including a foot 76 configured to contact the stacked packing elements 110 to apply an axial load thereto. The channel 40 and the corresponding chamber formed thereby in combination with the chamber 78 of the bucket-like structure 74 form a pressurized fluid chamber.

[0045] The follower element 70 may be placed in a first or initial preload position where the uppermost surface of the bucket-like structure 74 of the follower element 70 is adjacent to or in contact with the floor or bottom wall surface 74C of the gland channel 40. The exterior or outer surface of the walls 74A, 74B of the bucket-like structure 74 may also contact the side walls or sides of the gland channel 40 if desired. The channel 40 in combination with the chamber 78 of the bucket-like structure 74 forms a fluid chamber that can be pressurized by the fluid source 12 to move the follower element 70 axially inward to a loaded or applied position where the feet 76 of the follower element apply an axial load to the stacked set of packing elements 110. When axially loaded, the packing elements 110 form a fluid seal to help reduce or prevent leakage of process fluid from the fixture 50.

[0046] The pressure regulation system 10 provides a fluid, such as water, oil, air, or nitrogen, from a fluid source 12, which passes through a fluid regulator 14 to a pressure regulator 16. The pressure regulator 16 can be controlled by an electronic device 22, either directly or via a network 20, and optionally remotely. The electronic device 22 serves to set or define the pressure of the fluid leaving the pressure regulator 16 by establishing or setting a pressure level. Preferably, the pressure of the fluid leaving the pressure regulator 16 can be set manually via a setting element 16C. The fluid leaving the pressure regulator 16 can be selected according to the needs of the system. The pressurized fluid is introduced by suitable conduits or piping to a fluid supply port 38 formed in the gland 30. The fluid supply port 38 communicates with a channel 40 in the gland and cooperates with a chamber 78 in the follower element to form a pressurized fluid chamber.

[0047] The pressurized fluid acts on the bucket-like structure 74 of the follower element 70, specifically, on a piston load area 84 defined between an outer surface of the radially outermost wall 74A of the bucket-like structure 74 and an outer surface of the radially innermost wall 74B of the bucket-like structure 74. The piston area 84 defined by the bucket-like portion of the follower element is sized and dimensioned such that the axial load applied to the packing element through the follower element is sufficient to provide a seal of the process fluid within the stationary apparatus, given the pressure of the fluid provided by the fluid source 12. One skilled in the art would be able to readily determine the appropriate amount of piston area based on the overall dimensions of the packing load assembly, including the size of the follower element and gland, and the pressures of the source and process fluids. The force of the pressurized fluid acting on the piston area 84 of the follower element 70 axially moves the follower element 70 from a preloaded position to a loaded position and therebetween, if the follower element 70 is sufficiently pressurized. That is, when sufficiently pressurized, the piston loaded follower element 70 moves axially to a second loaded operating position to apply a selected load force to the packing element 110. In this second position, the upper bucket-like 74 portion of the follower element 70 is spaced from the floor of the gland channel 40. The fluid supply port 38 may be coupled to any suitable fluid supply.

[0048] The electronic device 22 can optionally control the amount of force applied to the packing element by varying, adjusting, or controlling the pressure of the fluid at the pressure regulator 16. That is, the pressure regulator 16 can sense the pressure in the packing load assembly 18 by sensing the fluid pressure at its fluid outlet 16B. The electronic device 22 can control the outlet pressure of the pressure regulator 16 by adjusting or manipulating a setting element of the pressure regulator. In this manner, the pressure applied to the packing element 110 via the piston load follower element 70 can be varied or adjusted in real time based on the sealing ability of the packing material and based on the load characteristics of the packing element 110. In particular, the pressure of the process fluid can change during operation of the packing load assembly, and the sealing ability or characteristics of the packing material can change over time. In this manner, the pressure in the packing load assembly changes, and therefore the load force applied to the packing element required to maintain a fluid seal also changes over time. The electronic device 22 via the pressure regulator can vary, adjust or modify the pressure of the pressurized fluid introduced to the packing load assembly 18 to apply and maintain a selected constant or uniform pressure to the packing element in real time. This force can thus be continuously and dynamically controlled to maintain a substantially uniform pressure on the packing element 110. Alternatively, the pressure of the fluid supplied to the packing load assembly 18 can be set by the pressure regulator by manually adjusting the regulator setting element 16C. The terms "substantially uniform" or "substantially constant" as used herein are intended to include the ability to adjust, vary or control the pressure of the fluid supplied to the packing load assembly such that the pressure varies by less than 2.0 psi, and preferably less than 1.0 psi.

[0049] According to one embodiment, the force applied to the packing element 110 via the piston load follower element 70 can be remotely controlled via any suitable network 20. Additionally, the fluid supply pressure provided to the packing load assembly 18 can be controlled such that the pressure is automatically adjusted based on the wear characteristics of the packing material of the packing element 110. There is no need to manually assess the sealing ability of the packing material or manually adjust the force applied to the packing element 110, such as by tightening the gland bolts, as is done in the prior art. Rather, the system 10 of the present invention can remotely control the load pressure applied to the packing element 110 and control it in an automated manner, thereby reducing or eliminating the need to manually tighten the gland bolts.

[0050] Additionally, the gland 30 and piston load follower element 70 can form a cartridge capable of generating a hydraulic or pneumatic cylinder actuation force. Thus, the present invention improves upon prior art products that dynamically load pump packing by providing a relatively constant or uniform force to the packing element 110, rather than the fluctuating forces of prior systems or the diminishing or changing force profile applied by the load spring, based on wear characteristics of the packing material. Thus, according to another embodiment, the present invention allows an operator to manually adjust the force applied to the packing material via the setting element 16C of the pressure regulator 16, if necessary or desired.

[0051] The loading mechanism of the present invention is operable with a wide variety of packing materials, including injectable packing materials. When injectable packing materials are used, the stuffing box can be refilled and thus no adjustment of the packing gland is required to return to its original position as the piston is pushed back within the gland and the optimum pressure load is maintained by the pressure regulator 16.

[0052] The gland 30 and / or piston load follower element 70 can be adjusted to provide a wide range of axial travel and pressure, thus eliminating or reducing the need for periodic manual adjustments required with conventional bolted glands.

[0053] The present invention also provides more accurate packing load control than typical bolted gland assemblies. Additionally, the system of the present invention allows for remote adjustment for safety (e.g., no manual adjustment of gland bolts near the rotating shaft). Specifically, many plant regulations do not allow for a mechanic to be near a rotating element after the pump has started. However, the system 10 of the present invention can be configured to allow the packing gland to be easily and remotely (i.e., from a safe distance) adjusted. Additionally, the system 10 can employ existing hydraulic (i.e., water or oil) or pneumatic (i.e., air or nitrogen) systems present in many industrial facilities, eliminating the need for significant retrofitting of fixtures to accommodate these gland and follower element assemblies.

[0054] In the system of the present invention, the load applied to the packing element 110 can be relatively constant or uniform, compared to prior art systems in which the deflection of the loading structure changes over time, thus subjecting the packing element 110 to a non-constant or varying load.

[0055] It will thus be seen that the present invention effectively attains the objects set forth above, among those made apparent from the preceding description. Since certain changes may be made to the above construction without departing from the scope of the invention, it is intended that all matter contained in this description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

[0056] Moreover, the following claims are to be understood as covering all the general and specific features of the invention described herein, as well as all statements regarding the scope of the invention.

Claims

1. A pressure regulation system (10) for a fastening device (50) using a set of stacked packing elements (110), comprising: a fluid source (12) for providing a source of fluid; a pressure regulator (16) for adjusting the pressure of the fluid to form a pressurized fluid; a packing load assembly (18) for sealing process fluid within the retention device (50), the packing load assembly (18) for applying an axial load force from the pressure regulator (16) to the packing elements (110) via the pressurized fluid, the packing load assembly (18) including an axially movable follower element (70) and a gland (30) for receiving the follower element (70), the gland (30) being axially disposed immediately adjacent to the retention device (50) and constructed and arranged to be fixed directly to the retention device (50), the follower element (70) being disposed between the packing elements (110) and the gland (30) and contacting at least one of the packing elements (110) at a first end and selectively contacting the gland (30) at an opposing second end; The gland (30) is a body (32) having a top surface (32A), an opposing bottom surface (32B), and a side surface (32C); a plurality of fastener-receiving openings (34) formed in said body (32) for receiving fastener elements (90); a gland channel (40) formed in the bottom surface (32B) of the body (32) defining a gland pressure chamber for receiving the second end of the follower element (70); a fluid supply port (38) formed in said side (32C) and in fluid communication with said gland channel (40).

2. 2. The pressure regulation system of claim 1, wherein the pressure regulator (16) includes an inlet (16A) for receiving the fluid from the fluid source (12) and an outlet (16B) for supplying the pressurized fluid.

3. 10. The pressure regulation system of claim 1, further comprising a fluid regulator (14) disposed between the fluid source (12) and the pressure regulator to regulate the flow of the fluid therebetween.

4. The pressure regulation system of claim 3 , wherein the fluid regulator comprises a check valve.

5. The ground channel (40) has a bottom wall, first and second opposing side wall surfaces, 2. The pressure regulation system of claim 1, further comprising a sealing channel (42, 44) formed in each of said first and second opposing sidewall surfaces for receiving a sealing element (46, 48).

6. 2. The pressure regulation system of claim 1, wherein the follower element (70) includes a first end having a bucket-like structure (74) and an opposing second end having a stem-like structure (75), the bucket-like structure (74) having a U-shaped body having opposing first and second side walls (74A, 74B) and a bottom wall (74C) forming a pressure chamber (78), and the stem-like structure (75) has a foot (76) at a distal end thereof for contacting an axially outermost one of the plurality of packing elements (110).

7. 7. The pressure regulation system of claim 6, wherein the bucket-like structure (74) is sized and configured to be at least partially received within the gland channel (40) of the gland (30).

8. 7. The pressure regulation system of claim 6, wherein the follower element (70) is movable between a first preload position, in which the follower element (70) is disposed at an axially outermost position, and a second loaded position, in which the follower element (70) moves axially inward and the foot (76) of the follower element contacts and applies a load force to the axially outermost one of the plurality of packing elements (110).

9. 7. The pressure regulation system of claim 6, wherein the gland channel (40) has opposing sidewalls spaced radially from one another and connected by a bottom wall, and the movable follower element (70) is configured to move between a first preload position in which the bucket-like structure (74) of the follower element is disposed within the gland channel (40) and an upper surface of the bucket-like structure contacts the bottom surface of the gland channel, and a second loaded position in which the follower element (70) moves axially inward and the upper surface of the bucket-like structure (74) is axially separated from the bottom wall of the gland channel (40).

10. 7. The pressure regulation system of claim 6, wherein the gland pressure chamber of the gland and the pressure chamber of the follower element cooperate to form a pressurized chamber for selectively moving the follower element axially as a function of the pressure of the fluid in the pressurized chamber.

11. 3. The pressure regulation system of claim 2, further comprising an electronic device (22) in communication with and for controlling the pressure regulator (16), the electronic device controlling the pressure of the pressurized fluid exiting the outlet (16B) and conveyed to the packing load assembly (18).

12. 12. The pressure regulation system of claim 11, wherein the gland (30) has a fluid supply port (38) formed therein, and the pressure regulator (16) conveys pressurized fluid to the follower element (70) through the fluid supply port (38).

13. A packing load assembly for mounting to a fixture using a set of stacked packing elements (110), comprising: A gland (30) for attachment to a fixing device (50), a body (32) having a top surface (32A), an opposing bottom surface (32B), and a side surface (32C); a plurality of fastener-receiving openings (34) formed in said body (32) for receiving fastener elements (90); a gland channel (40) formed in the bottom surface (32B) of the body (32) to define a gland pressure chamber; a gland including a fluid supply port (38) formed in said side (32C) and in fluid communication with said gland channel (40); an axially movable follower element (70) coupled at one end to said gland (30) and coupled at an opposing end to at least one of said packing elements (110), a first end having a bucket-like structure (74) with a generally U-shaped body having first and second opposing side walls (74A, 74B) and a bottom wall (74C) forming a chamber (78); and an opposed second end having a stem-like structure (75) having a foot (76) at its distal end for contacting an axially outermost one of the plurality of packing elements (110).

14. 14. The packing load assembly of claim 13, wherein the gland pressure chamber and the chamber (78) of the bucket-like structure (74) are fluidly coupled to form a pressurized chamber for axially moving the follower element (70) between a first preload position and a second loaded position.

15. 15. The packing load assembly of claim 14, wherein the gland channel (40) has first and second radially spaced apart wall surfaces and a bottom wall connected to the first and second wall surfaces, wherein the bucket-like structure (74) is disposed within the gland channel (40) and an upper surface of the bucket-like structure (74) contacts the bottom wall of the gland channel (40) when the follower element (70) is disposed in the first preload position, and wherein the upper surface of the bucket-like structure (74) is radially separated from the bottom wall of the gland channel (40) when the follower element (70) is disposed in the second loaded position.

16. 14. The packing load assembly of claim 13, wherein the gland (30) has a plurality of centering openings (36) formed in an upper surface thereof, each of the plurality of centering openings (36) being sized and configured to receive a centering element (114).

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