Self-Aligning and Leak Monitoring Stuffing Box

Abstract

Disclosed is an improved stuffing box that is adapted to articulate within a housing body to accommodate a polished rod misalignment, maintain compression of a graphite stuffing material, prevent cross contamination of debris through the stuffing box interior and provide a means to monitor for fluid leaks. The device comprises a housing having an internally supported stuffing box, where the stuffing box is supported along an angular seat within the housing that allows reorientation of the box as the polished rod passes therethrough. A bonnet applies continuous load onto a gland pusher element using spring washers to compress the stuffing material through discontinuous heat cycles, while an upper and lower wiper element clean the polished rod before entering the stuffing box interior. A lantern ring within the stuffing box provides a venting aperture into the interior of the housing, whereby a pressure indicator monitors for fluid leaks during operation.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 61/557,770 filed on Nov. 9, 2011, entitled “Articulating Stuffing Box.” The above identified patent application is herein incorporated by reference in its entirety to provide continuity of disclosure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to drilling pumpjacks and stuffing box assemblies. More specifically, the present invention pertains to a new stuffing box that accommodates misalignment of an oil well polished rod, maintains compression of the stuffing box stuffing material, and further provides a means to monitor for leaks during deployment.

Most oil production involves the pumping of crude oil from underground reservoirs to the surface using a pumpjack device, which is a reciprocating mechanical device that draws oil through a well and to the surface for storage and further refining. Pumpjacks generally comprise a reciprocating horses head driven by a motor and counter weight. The head connects to a bridle and further connects to a polished rod. The polished rod reciprocates in and out of a stuffing box, which is a close-fit assembly that cleans the polished rod, prevents debris from entering or exiting the well, and further prevents fluid from leaking from the well during operation. Below the stuffing box, the polished rod connects to a series of sucker rods that travel the length of the well and downward toward the oil reservoir.

During operation, the stuffing box provides a dynamic seal along the length of the polished rod. Most conventional stuffing boxes include a central pathway through which the polished rod travels, while stuffing or packing material is compressed against the sidewalls of the polished rod to create a fluid seal and to prevent contamination from either side of the stuffing box from passing therethrough. A common problem with most conventional stuffing boxes is the propensity for the stuffing material to wear away over time. This problem arises generally when the polished rod and stuffing box to become misaligned over a period of use and as abrasive contaminants enter the stuffing box and wear away the stuffing material. Misalignment occurs when the mechanical assemblies naturally loosen or shift over time with respect to one another. This misalignment creates lateral loads on the packing material within the stuffing box, distorting the material and causing increased wear and heat. The existence of debris and contaminants within the box only execrate this wear. Eventually, the stuffing box may fail to provide an adequate seal around the surface of the polished rod, requiring workers to replace the packing material or the entire stuffing box assembly to prevent leaks.

The present invention provides a new stuffing box assembly that is adapted to address the current misalignment and wear problems in the art of stuffing boxes. The present invention accounts for misalignment of a polished rod in its construction, maintains compression of the packing material during non-uniform heat cycles, prevents contaminates from entering the box interior, and actively monitors for leaks from the stuffing box such that the operation can be shut down before a catastrophic leak event occurs. The first drawback of common stuffing boxes is the problem of misalignment of the articulating polished rod within the interior of the box, for which the present invention provides an articulating and self-orienting box structure that can pivot and rotate to account for side loads and non-concentric polished rod movement. Another drawback of most stuffing boxes is the build-up of heat through contaminate friction and non-continuous use in the field (heat cycling). The present invention utilizes a graphite packing material to keep the rod sealed and lubricated, while continuous compression is kept on the packing material using Belleville spring washers and a pusher gland assembly that can account for thermal expansion and maintain compression.

Further drawbacks of most common stuffing boxes include inadequate leak detection and insufficient metallurgy to operate long-term in the typical oil well environment. Leaks occur most commonly through bottom ring failure of a stuffing box, which can create shutdowns for repairs and for environmental inspections, which are both costly and time consuming. To address these concerns, the present invention utilizes a relief port to monitor within the stuffing box to monitor pressure within the device housing, capturing leaks as they occur for further action to be taken. Both ends of the stuffing box include wiper elements to remove debris, while the components of the assembly utilize nickel plated or stainless material to prevent corrosion from fluids and acids that can otherwise damage the stuffing box components. It is herein desired to disclose a stuffing box assembly that addresses the major drawbacks of most common stuffing boxes, and one that fulfills a long felt need for a reliable and robust assembly that can be readily deployed and implemented without major changes to existing pumping assemblies.

2. Description of the Prior Art

Devices have been disclosed in the prior art that relate to stuffing boxes and shaft supports. These include devices that have been patented and published in patent application publications, and generally relate to improved means of applying compression to a stuffing material or accommodating for shaft lateral movement through a reciprocating cycle. The following is a list of devices deemed most relevant to the present disclosure, which are herein described for the purposes of highlighting and differentiating the unique aspects of the present invention, and further highlighting the drawbacks existing in the prior art.

Specifically, U.S. Pat. No. 5,711,533 to Angelo discloses an oilfield stuffing box that permits lateral displacement of the polished rod using a pair of flange plates that utilize bolt holes appreciably larger in diameter than the bolts employed to hold the plates together. As the polished rod moves laterally through its motion, the flanges are capable of moving relative to one another to account for the misalignment in lateral direction. A static seal between the two mating flange plates prevents leaks from occurring during the flange shifts. The stuffing box is supported by a divided first and second flange, the second being threadably connected to the wellhead and the first flange connecting to the stuffing box and further to the second flange to encapsulate the stuffing box within an interior volume defined by the two flanges. While the Angelo device allows for lateral movement of the polished rod, its construction relies on oversized holes that permit displacement of the flanges relative to one another. This arrangement can lead to wear between the flanges and is a less robust means of compensating for misalignment. A seal between the flanges prevents leaks during misalignment of the flanges; however no backup system is provided for preventing leaks after they occur.

U.S. Pat. No. 5,865,245 to Trout discloses a stuffing box gland that is adapted to compress the packing material against an internal polished rod. The housing includes a central passageway and a lower end for exerting compressive force on the packing within the stuffing box. Within the gland housing is a reservoir for storing lubricant material, whereby the exterior surface of the polished rod and the corresponding interior surfaces of the gland housing can be lubricated during operation. A wiper element is disposed along the lower portion of the housing to remove debris from the polished rod attached to the rod within the well, while an upper housing elastomeric wick removes debris from the polished rod when entering from above the housing. The Trout device discloses a stuffing box compression housing and polished rod lubrication device, which reduces wear caused by friction and abrasive debris. The present invention provides an upper and lower mounted polished rod debris removal means; however the design and structure of the Trout device diverges significantly from that of the present invention.

U.S. Pat. No. 5,845,909 to Angelo discloses a stuffing box designed to exert radial compression on an internal polished rod using a gland member and a plurality of stacked packing rings. The gland member surrounds the polished rod and encapsulates the packing rings, exerting axial load on the packing rings, where the rings are annular rubber carriers having a tapering upper and lower surface and an annular plastic dynamic seal. The tapering shape of the packing rings allows the axial load from the gland member to transform into radial compression on the polished rod, creating a dynamic seal to remove debris. The design of the packing rings accounts for thermal expansion of the rubber carriers and therefore flexing of the packing rings. The Angelo device provides a unique means of exerting load on the polished rod and a structure that accounts for thermal loads; however its design does not account for lateral misalignment of the polished rod and the stuffing box or address a need to monitor for leaks during operation.

U.S. Pat. No. 6,585,416 to Rimmer discloses a self-aligning shaft support for a pump pull rod that accounts for both rotary and reciprocal motion. A guide element bears against a bearing element within a housing, whereby lateral or angular movement of the shaft is accounted for at the bearing element interface between the housing and guide element. An angular face upon which the bearing element rests provides for angular movement of the guide element, whereby the angular face establishes a spherical ledge upon which the guide element rotates and bears against, allowing misalignment of the polished rod via relative motion along this interface. Similar to the Rimmer device is U.S. Pat. No. 2,628,112 to Herbard, which discloses a self-aligning and lubricating stuffing box having a housing that includes a spherical surface concave downward with a bottom bearing ring and an upper spherical surface concave upward with an upper bearing ring. The concave surfaces support a floating gland assembly that includes the stuffing material and a shaft therethrough.

Both the Rimmer and Herbard devices disclose a stuffing box and shaft support that accounts for misalignments between the shaft and the stuff box housing. The misalignment is handled using a curved bearing surface, in a similar fashion as that provided for in the present invention; however, the design of the present housing provides for misalignment correction, lubrication of bearing elements, a means along the upper and lower portion of the housing to remove debris and sediment, as well as a means to monitor for well leaks and shut down operation as necessary in the event of a leak.

Finally, devices having been discloses that account for shaft misalignment through oversized housings with respect to the interior stuffing boxes. Both U.S. Pat. Nos. 2,235,289 and 2,267,183 to Dunn and Williams, respectively, offer interior clearance between the interior packing unit making contact with the interior reciprocating shaft and the exterior housing. The clearance allows lateral movement of the packing unit as the shaft reciprocates through its motion. Wearing bushings or similar mechanical bearing devices are provided to maintain a secure seal on the shaft while the lateral motion occurs. These devices, while offering a means to account for shaft misalignment, fail in the same way as the Trout device, where mechanical clearance is utilized as a means to allow motion. The present invention contemplates a curved bearing surface together with an interior and exterior housing that allow the polished rod to angularly move within the device without binding or increasing wear on the stuffing material.

The present invention provides a new stuffing box that maintains the compression of the stuffing material against a polished rod using a self-orienting construction to account for misalignments, a stuffing gland that accounts for heat cycling, a pair of wiper elements that remove contaminants from the polished rod and components with sufficient metallurgy to survive highly corrosive environments. Finally, a venting aperture allows for leaks to be monitored within a housing outside of the articulating stuffing box, allowing operational shutdown before large scale leaks occur. It is submitted that the present invention is substantially divergent in design elements from the prior art, and consequently it is clear that there is a need in the art for an improvement to existing stuffing box devices. In this regard the instant invention substantially fulfills these needs.

SUMMARY OF THE INVENTION

In view of the foregoing disadvantages inherent in the known types of stuffing box devices now present in the prior art, the present invention provides a new stuffing box construction that can be utilized for providing convenience for the user in oil well operations for deploying a robust and reliable stuffing box assembly.

It is therefore an object of the present invention to provide a new and improved stuffing box device that has all of the advantages of the prior art and none of the disadvantages.

It is another object of the present invention to provide a stuffing box device having a self-orienting structure that aligns itself with a polished rod passing therethrough to prevent the stuffing box from receiving increased lateral loads that would otherwise create higher levels of friction and wear on the stuffing material.

Another object of the present invention is to provide a stuffing box device that includes graphite stuffing material that is compressed using spring washers to maintain compression on the stuffing during heat cycling, preventing leaks and loosening of components over time and in between long periods of non-use.

Another object of the present invention is to provide a stuffing box device that includes a lantern ring within the stuffing box such that a relief port is provided, whereby leaking fluid will exit the port and into the stuffing box housing. Within the housing a fluid pressure indicator can be positioned to detect the leak and alert workers of the event.

Yet another object of the present invention is to provide a stuffing box device that includes an upper and lower wiper ring to remove dirt and sediment from the polished rod prior to entry into the stuffing box, whereby abrasive contaminates are prevented from entering the stuffing box and wearing the stuffing material.

A final object of the present invention is to provide a stuffing box device that includes nickel plated steel or stainless steel components to prevent corrosion caused by contact with well fluids.

Other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Although the characteristic features of this invention will be particularly pointed out in the claims, the invention itself and manner in which it may be made and used may be better understood after a review of the following description, taken in connection with the accompanying drawings wherein like numeral annotations are provided throughout.

FIG. 1 shows a cross section assembly view of the present invention.

FIG. 2 shows a cross section view of the body housing.

FIG. 3 shows perspective and overhead view of the body housing.

FIG. 4 shows a cross section view of the stuffing box.

FIG. 5 shows a cross section and overhead view of the seat.

FIG. 6 shows a cross section and overhead view of the gland

FIG. 7 shows a perspective view of the polished rod entering the gland above the housing.

FIG. 8 shows a cross section and overhead view of the gland pusher element.

FIG. 9 shows a cross section view and overhead view of the device bonnet.

FIG. 10 shows a cross section, overhead and perspective view of the ported lantern ring.

FIG. 11 shows a perspective view of the assembly in a working state, accepting a polished rod therethrough and connecting to a wellhead.

FIG. 12 shows another external perspective view of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is made herein to the attached drawings. Like reference numerals are used throughout the drawings to depict like or similar elements of the stuffing box. For the purposes of presenting a brief and clear description of the present invention, the preferred embodiment will be discussed as used for preventing misalignment of a polished rod with respect to the stuffing box, reducing wear, preventing contamination, preventing corrosion and detecting leaks as they occur within the housing. The figures are intended for representative purposes only and should not be considered to be limiting in any respect.

Referring now to FIG. 1, there is shown a cross section view of the stuffing box assembly 11 of the present invention. The assembly comprises a housing body 12 having an open interior volume 13 adapted to accept a rotating stuffing box device 20 therein. The interior of the housing body 13 comprises a beveled or contoured surface 14 and a contour seat 30 that comprises low friction interface upon which the base of the stuffing box device 20 is perched thereagainst. The stuffing box 20 is an elongated member having a rounded upper 22 and lower 21, whereby the rounded lower surface of the stuffing box 20 interfaces with the seat 30 and contoured surface 14 of the housing 12 to allow relative sliding. This allows the stuffing box device 20 to rotate relative to the housing 12. The upper portion 22 of the stuffing box connections to a gland pusher 40, which is sandwiched between an upper gland 50 and the upper portion 22 of the stuffing box. Spring washers or Belleville spring washers 51 and threaded bolts 52 compress the gland pusher 40 against the upper portion 22 of the stuffing box, drawing the gland 50 against the gland pusher 40.

The gland pusher 40 includes an outer extended diameter and a lowermost reduced diameter portion, whereby the lower portion of the gland pusher 40 compresses a stuffing material 60 within the stuffing box 20. The stuffing box stuffing material 60 is preferably a Grafoil or graphite packing material. The gland pusher 40 compresses the packing material 60 against the outer surface of the polished rod to maintain a dynamic fluid seal thereagainst, preventing well fluid from bypassing the packing material. The articulating structure of the stuffing box 20 itself within the housing 12 allows for misalignment of the polished rod to be accounted for by slight rotation of the stuffing box, preventing side loads and higher levels of wear.

To close off the open interior 13 of the housing body 12, an upper bonnet covering 70 is secured via a plurality of bolted fasteners 71 over the housing 12, whereby the bonnet 70 provides an opening within its center for clearance of the gland pusher 40 during periods of misalignment and lateral movement of the push and polished rod. In this way, the housing 12 remains stationary and is threadably connected 15 to a wellhead, while the polished rod travels in and out of the stuffing box 20 through the gland 50, gland pusher 40, housing seat 70, and stuffing box interior. The stuffing box 20, gland 50, and gland pusher 40 are capable of lateral movement to accommodate slight misalignments of the polished rod as it undergoes its reciprocal movement through the assembly. To prevent contaminates from entering the assembly, a first and second wiper ring 16 is installed on the top and bottom of the assembly to eliminate any debris from being pulled or pushed through the packing, which would otherwise be an abrasive that creates increased wear on the packing 60.

Within the interior 13 of the stuffing box is a lantern ring 80 that surrounds the polished rod and packing material. The lantern ring 80 comprises an orifice that allows leaking fluid to escape the packing material 60 and flow from the stuffing box into the housing interior 13. In the event of a fluid leak, the fluid will flow through the aperture and accumulate within the housing. A pressure sensor or switch is positioned within the housing to monitor the build-up of fluid. This sensor can provide workers with advanced notice of a leak as it occurs and before it becomes more wide spread. This allows workers to cease operation for replacement of the packing material 60 or repair of any of the elements in the assembly. Traditional stuffing boxes will fail without warning, creating workplace hazards, work stoppages and environmental clean-ups. The pressure switch monitors fluid pressure within the housing, whereupon a threshold pressure is indicated, a signal can be transmitted to the workers of the leak event.

Referring now to FIGS. 2 and 3, there are shown cross section and perspective views of the housing body 12 of the present invention. The housing body 12 comprises a cylindrical body having upstanding sidewalls 10, an open upper 17 having outward flanges 18 and a reduced lower that forms into a threaded coupling 15 adapted to connect directly to a wellhead. The interior 13 of the housing accepts the articulating stuffing box therein, while the base 14 of the interior comprises a downwardly slopping interface upon which the stuffing box is supported. This lower surface also accepts an angled seat, which extends the upwardly angled base of the housing and also provides securement of a circular seal 90 (FIG. 1) that prevents fluid from entering or exiting the housing during operation. The seat 30, as shown in FIG. 5, is a circular structure having an open interior 45, sloping inner walls 46 to interface with the stuffing box and a lower channel 19 for placement of a seal 90 (FIG. 1) between the seat and the housing interior 13.

Along the sidewall of the housing is a vent hole aperture 25. The vent hole 25 allows for placement of a pressure switch to shutdown the pumping operation in the event of a packing or seat leak, therefore stemming the leak from continuing. Along the upper portion of the housing is an outward flange 18 that comprises a plurality of fastener locations 26 through which to secure the bonnet fasteners therethrough and enclosure the upper portion of the housing. Finally, the lowermost portion 15 of the housing incorporates a passageway for the polished rod, whereby the polished rod enters the wellhead and connects to a sucker rod in the well. The passageway 15 is an elongated member having external threads for which to threadably engage a wellhead without alteration thereof.

Referring now to FIG. 4, there is shown a cross section view of the self-orienting stuffing box 20 adapted to be placed within the interior of the housing, support stuffing material against the polished rod, and provide a dynamic seal against the rod as it passes therethrough. FIG. 4 shows the stuffing box in an inverted orientation, where the upper portion of the box includes tapped apertures 23 to accept fasteners from the upper gland. The box 20 itself comprises an elongated member having a central passage way 24 to support packing material and a polished rod therethrough. A ledge 35 within the interior 24 supports the packing vertically as it is compressed downward using the packing glad and glad bolt fasteners. The compression is further assisted using spring washers 51 (FIG. 1) that prevent any reducing in compression due to heat cycling of the material. The packing is compressed downward, causing a natural expansion of its cross section such that the packing bears against the surface of the polished rod as it passes through 24, establishing a dynamic fluid seal that prevents well fluid from exiting the well. Positioned at the base of the stuffing box and below the ledge 35 is a wiper element 16 (FIG. 1) support 36, which cleans the surface of the polished rod as it is drawn into the stuffing box interior 24. This prevents sediment, debris and thick fluid from contacting the stuffing without a first pass of a wiper element 16 (FIG. 1). A second, upper wiper element 16 (FIG. 1) also provides the same functionality, and is positioned within the upper gland as shown in the cross section in FIG. 6.

The stuffing box comprises a largely cylindrical body structure and a first and second end. The first 22 and second 21 end are adapted to bear against the sloped interior surfaces of the housing as the box orients itself to account for misalignment of the polished rod passing therethrough. The first 22 and second 21 end of the box comprises a radius, creating a rounded edge 37 and forming a near spherical interface on both ends. The interface slides against the sloped interior supports of the housing as the polished rod moves through the box in both upward and downward directions. The box 20 is therefore floating within the housing and can orient itself as necessary given a misalignment of the polished rod as it moves through its motion. The range of motion of the polished rod and thus the orientation limits of the stuffing box are limited by the opening provided by the bonnet 70 (FIG. 1), which provides oversized opening to account for lateral displacement of the polished rod entering the assembly.

In the event of packing wear and eventual failure, a first and second venting port 38 is provided along the sidewalls 39 of the stuffing box 20 to allow fluid to escape into the interior of the housing. When this event occurs, the accumulation of fluid within the interior of the housing is monitored, such that operations can be ceased to replace the stuffing material. The stuffing itself is a graphite material that has inherent lubrication; however the stuffing is a wear item that will always require replacement over its lifetime. The given lifetime of the present stuffing box stuffing material is adapted to far exceed most traditional stuffing box stuffing material, where abrasive contaminates and polished rod wear are significantly reduced in the present assembly.

Referring now to FIG. 6, there is shown a cross section view and overhead view of the upper gland 50. The gland 50 is a circular compression element that sandwiches a gland pusher element against the stuffing material within the stuffing box interior. The gland 50 comprises an open interior to accept the polished rod therethrough, while its section includes a plurality of fastener holes 56 through which bolts are passed to clamp the gland and stuffing box together. Within the open interior, a notch 57 is provided along the interior surface to support the second wiper element, which cleans the polished rod as it passes through the top of the stuffing box assembly. This wiper element 16 (FIG. 1) removes dirt, sand and other debris from the external environment around the well, preventing contamination and abrasive wearing of the stuffing material that may otherwise occur at the interface between the polished rod and the stuffing material. Referring to FIG. 7, there is shown a view of the polished rod 100 entering the upper gland 50, passing through the wiper element 16, through the bonnet 70 of the housing 12 and into the stuffing box interior.

Referring now to FIG. 8, there is shown a cross section view and overhead view of the gland pusher element 40. The gland pusher element 40 is a hollow member having an open interior 65 to accept the polished rod therethrough and stepped sidewalls 66. The upper portion 67 of the pusher element has a wider wall thickness to interface with the upper gland between the compression fasteners. The fasteners draw the gland against the pusher element 40, whereby the base 68 of the pusher element fits within the interior passageway of the stuffing box and bears against the stuffing material about the sides of the polished rod. In this way, the gland pusher element 40 is used to compress the stuffing material and ensure a close tolerance fit between the polished rod and the stuffing material during operation. Spring washers 51 (FIG. 1) maintain uniform compression of the fasteners against the gland pusher 40 and thus compression of the stuffing material.

Referring now to FIG. 9, there is shown a cross section and overhead view of the bonnet 70. The bonnet 70 secures over the housing via a plurality of fasteners that extend through the bonnet and into the housing upper flange. The bonnet 70 comprises an open interior 72 to accept the polished rod and the compression fasteners of the upper gland. The opening 72 in the bonnet 70 is adapted to provide freedom of lateral movement of the polished rod, where the diameter of the opening 72 determines the extremes of the misalignment for which the stuffing box and upper gland may accommodate before the fasteners of the glad bear against the interior walls of the opening. The bonnet underside includes notches 19 to accept circular seals 90 (FIG. 1) therein. In an alternate embodiment, the bonnet lower surface includes angled interior projections that provide a curved means for which the upper portion of the stuffing box to bear and slide thereagainst, providing a mirrored interface with respect to the interior seat.

Referring now to FIG. 10, there is shown a cross section, overhead and perspective view of the lantern ring 80 positioned within the passageway of the stuffing box. The lantern ring 80 is a close fit assembly that surrounds the polished rod and provides a first and second port 81 through which leaking fluid may escape into through the apertures of the stuffing box and into the open interior of the housing. The lantern ring 80 is an elongated sleeve 82 having an upper and lower portion 82 of greater outer diameter than the body portion 83 of the sleeve where the ports 81 are located to allow the internal pressure within the stuffing box passageway to be released into the stuffing box and outer chamber. This allows for detection of a leak that is caused by packing or stuffing box seal failure, which may then signal an alarm or shuts the pump down to prevent further damage.

Referring now to FIGS. 11 and 12, there are shown views of the assembly of the present invention in a working state and from an external perspective. The upper portion of the assembly comprises an upper gland 50 that includes a wiper element, which function to prevent dust and dirt accumulation at the packing entrance and to support bolts that compress the packing gland against the internal stuffing material. The glands 50 and stuffing box rotate with the polished rod 100, thereby eliminating distortion of the packing, as well as eliminating torque on the rod. The base of the stuffing box bears against a rounded housing seat within the base of the housing that comprises an RTFE or a similar low-friction surface and an O-ring seal that prevents blow by on the back of the seat. The articulation capabilities of the unit keep the pump aligned at all times. If the polish rod falls out of alignment, the packing ball may rotate within the housing to keep the packing in line with the rod.

The base of the housing 12 comprises a threaded wellhead connection 15, allowing the device to be installed onto a conventional oil wellhead 110. This enables the device to be used without requiring modification of an existing oil well head 110. All wetted components of the assembly are preferably comprised of a nickel-plated steel, stainless steel material, or similar corrosive resistance material. The fluid and sediment within well contains high levels of H₂S acid and other corrosive material. The use of material suitable for the intended environment enhances the life of each component and reduces replacement costs. The stuffing compression is held constant within the stuffing box via the use of the upper gland, tensioned bolts and Belleville spring washers 51 that maintain uniform tension on the bolts. The washers 51 flex in order to limit the stresses placed on the device that occur due to packing compression, which is caused by changes in temperature and pressure. Additionally, a wiper ring is installed on both the top and bottom of the packing system to eliminate any debris from being pulled or pushed through the packing. The stuffing material is therefore prevented from high levels of wear as a result of polished rod side loads and contaminates within the interior of the stuffing box. The stuffing material itself is a graphite material, which is a low friction material that reduces friction such that it does not readily overheat and wear. Grafoil packing is the preferred material, in that it does not have to be lubricated externally and is heat resistant, thereby preventing the device from heating up during periods of dry pumping which can be caused by failure of the pump, loss of suction that can occur due to gassing, level issues, or by a blocked discharge. The ability to operate without external lubrication frees workers from the task of monitoring the stuffing box lubrication levels and eliminates the requirement of lubricant material. The material itself is low friction and thus is uniformly lubricated, preventing pockets of wear and heat generation seen in traditional lubricated stuffing box stuffing material.

It is therefore submitted that the instant invention has been shown and described in what is considered to be the most practical and preferred embodiments. It is recognized, however, that departures may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

Claims

1. A stuffing box device, comprising:

a housing having an interior volume, upstanding sidewalls, an open upper, and an open lower;

a stuffing box adapted to fit within said housing interior, said stuffing box having sidewalls, a curved upper and lower surface, and an passageway therethrough;

said housing interior volume having a seat providing a sloping surface upon which said stuffing box curved lower surface is slideably supported;

an upper gland fastened to said stuffing box upper portion to compress a pusher gland against a stuffing material within said stuffing box interior;

a bonnet enclosing said housing open upper, said bonnet comprising an aperture therethrough;

said gland, pusher gland, bonnet, stuffing box and stuffing material having a pathway to accept a shaft therethrough.

2. The device of claim 1, further comprising a lantern ring within said stuffing box, said lantern ring comprising a sleeve having at least one venting port through which fluid and pressure may flow to said stuffing box.

3. The device of claim 1, wherein said stuffing box further comprises at least one venting aperture through which fluid and pressure may flow to said housing interior.

4. The device of claim 1, wherein said housing further comprises at least one aperture through which pressure is monitored within said housing interior.

5. The device of claim 1, wherein said upper gland fasteners compress said pusher gland against said packing material and spring washers maintain tension in said fasteners.

6. The device of claim 1, wherein said housing interior seat further comprises a seal to prevent fluid from entering or existing said housing interior through said housing lower.

7. The device of claim 1, wherein said housing open lower further comprises a threadable interface for connection to a wellhead.

8. The device of claim 1, wherein said stuffing box stuffing material is compressed against an internal ledge and against a shaft within said passageway to establish a dynamic fluid seal about said shaft.

9. The device of claim 1, wherein said packing is a graphite material requiring no external lubrication.

10. The device of claim 1, wherein wetted components of said assembly comprise a nickel plated steel.

11. The device of claim 1, wherein wetted components of said assembly comprise a stainless steel.

12. The device of claim 1, wherein said bonnet secures to a flange about said housing upper via a plurality of fasteners.

13. The device of claim 1, wherein said bonnet lower surface within said housing interior further comprises a curved interface for contact with said stuffing box curve upper surface.

14. The device of claim 1, wherein said upper gland further comprises an upper wiper element that wipes said shaft surface as it passes thereby.

15. The device of claim 1, wherein said housing interior seat a lower wiper element that wipes said shaft surface as it passes thereby.