Stuffing box assembly and sealing assembly for use therein

Information

  • Patent Application
  • 20070175627
  • Publication Number
    20070175627
  • Date Filed
    July 25, 2006
    17 years ago
  • Date Published
    August 02, 2007
    16 years ago
Abstract
A stuffing box assembly for use in sealing between a fixed housing and a rotatable member extending through the fixed housing comprising a housing forming a sealing assembly chamber, a rotatable member extending through the housing and a sealing assembly received in the chamber, the sealing assembly including an annular seal ring carrier, an annular seal ring carried by the carrier, the seal ring having an annular radially outer portion and an annular radially inwardly extending sealing lip, an annular seal ring spreader operatively engaged with the seal ring, an elastic biasing member operatively engaged with the seal ring spreader and an annular adjustable follower selectively axially immovable with respect to the housing, the spreader exerting a greater force on the sealing lip than the radially outer portion of the seal lip when the spreader is biased towards the seal ring.
Description
CROSS-REFERENCE OF RELATED APPLICATION

This Application Claims Priority from Provisional Application No. 60/736,891 filed Oct. 15, 2005 for Packing Assembly For Rotary Drilling Swivels, the disclosure of which is incorporated herein by reference for all purposes


BACKGROUND OF THE INVENTION

1. Field of the Invention


The present invention relates to a stuffing box and a sealing assembly for use in effecting fluid sealing between a fixed body and a rotating body and, in particular around the wash pipe of a rotary drilling swivel.


2. Description of Prior Art


In the drilling of oil and gas wells, a drill bit is rotated in a borehole by means of a string of drill pipe. The drill pipe is rotated on the surface mechanically by a rotating table mounted on a drilling platform or by a hydraulic motor, commonly referred to as a top drive. As is common in such oil and gas well drilling, drilling fluid or mud is circulated through the drill pipe and the drill bit to cool the drill bit and remove the cuttings, the mud being recirculated to the surface and the cuttings removed from the drilling fluid/mud so it can be reused.


The rotary drilling swivel commonly used in the drilling of oil and gas wells provides rotating support for the drill string suspended from it and a sealed passageway for circulating drilling fluids into the drill string. The drill pipe is in open-flow communication with a wash pipe, through which the drilling fluid flows, the wash pipe usually being stationary. A packing assembly forming part of the swivel rotates with the drill pipe, and is in sealing engagement with the wash pipe to prevent loss of drilling fluid out of the swivel assembly.


Depending on the depth of the well and/or well conditions, drilling fluid pressures can reach several thousand psi, and at these high pressures, conventional, prior art packing assemblies used to seal between the wash pipe and the rotary head to which the drill pipe is secured have reduced life, resulting in leaking.


In particular, as deeper wells are drilled at higher mud pressures, e.g., 6,000 psi, turning rates of 220 rpm and high flow rates of drilling mud, the wearing problem on the seals between the wash pipe and the rotary head to which the drill pipe is secured is exacerbated. For example, the wash pipe for a 3″ bore wash pipe may have a 3.65″ OD and rotate at 120 rpm at a maximum pressure of 3,500 psi. This calculates to PV of 398,565 psi-fpm. In contrast, when a 4″ bore wash pipe (OD=4,875″), typically used in deep, high-speed drilling, is employed at pressures of 6,000 psi and a turning rate of 220 rpm, a PV of 1,684,575 psi-fpm is reached. This PV value is typically more than four times more severe than that usually encountered in conventional drilling operations. Presently, packing materials used to seal between the wash pipe and the rotary head, under the severe conditions noted, have an expected life of from 20 hours to a maximum of several hundred hours. As is well known to those skilled in the art, once the packing fails, it is necessary to stop the drilling and replace the packing, an operation that in and of itself can take eight to ten hours. Furthermore, this is not the total downtime before drilling can be resumed. It will be appreciated that on a deepwater drill ship or rig, this amount of downtime translates to thousands of dollars and penalties.


Typical prior packings now used in rotary drilling swivels are usually made from molded rubber and fabric composites and in this regard, a number of combinations of various fabrics and elastomers can be employed depending upon the operating conditions. For example, a common elastomer is Buna-n rubber and a common fabric is cotton. To these composites can be added lubricating materials such as graphite, molybdemum disulfide, PTFE resins, etc.


It is becoming increasingly apparent that these typical prior art packings made from the materials described above do not have sufficient lifetime when operating under severe conditions of high mud pressures, high turning rates and high flow rates.


Presently, there are materials that can be used to make packings or seals for these systems that can withstand these higher PV's, as well as the high heat loads generated at the interface of the packing or seal lip and the wash pipe surface. Thus, while more sophisticated materials such as PTFE, PTFE alloys, high temperature plastics and rigid elastomers/rubber composites can withstand these harsh operating conditions, they have disadvantages which affect their sealing ability. These materials, while they perform well initially, lose their sealing ability once the drilling is stopped and/or the mud pressure is reduced, e.g., when it is necessary to add a new joint of drill string or for some other reason encountered in the drilling operation. The reason that seals of these more sophisticated materials fail to seal under these conditions, i.e., moving from high PV's to low PV's, is because of their material make-up. Typically these materials are generally hard or rigid elastomers, plastics, etc., and generally yield under the initial stress and accordingly, lose their interference engagement with the wash pipe, such that when mud pressure is brought back up to operating conditions leakage occurs. As noted above, conventional packing materials of softer elastomers/rubber composites have sufficient elasticity to maintain a sealing force under high or low PV's, but they have poor wear characteristics.


SUMMARY OF THE INVENTION

In one embodiment the present invention provides a sealing assembly for use in sealing between a relatively rotatable housing and a member extending through the housing. The sealing assembly includes an annular seal ring carrier; an annular seal ring carried by the carrier, the seal ring having an annular, radially outer portion and an annular, radially inner portion; an annular seal ring spreader operatively engaged with the seal ring; an elastic biasing member operatively engaged with the seal ring spreader; and an annular follower. The spreader exerts a greater force on one of the radially inner or outer portions than the other of the radially inner or outer portions when the spreader is biased toward the seal ring.


In another embodiment, the present invention provides a stuffing box or packing assembly for use in sealing between a fixed housing and a rotatable member extending into the fixed housing, the stuffing box assembly including a housing having a bore for receipt of a rotatable shaft, the housing forming a sealing assembly chamber, and a sealing assembly as described above received in the sealing assembly chamber in the housing.




BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is an elevational view, partly in section, showing a prior art stuffing box/sealing assembly used in a rotary drilling swivel; and



FIG. 2 is a view similar to FIG. 1 showing one embodiment of the stuffing box/sealing assembly according to the present invention.



FIG. 3 is a view similar to FIG. 1 showing another embodiment of the stuffing box/sealing assembly according to the present invention.




DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Referring first to FIG. 1, there is shown a wash pipe/stuffing box or packing gland assembly used in a conventional rotary drilling swivel, the stuffing box assembly including a conventional prior art sealing or packing assembly, all of which are well known to those skilled in the art. Referring then to FIG. 1, a wash pipe 6 extends through a stuffing box assembly shown generally as 8 comprising a packing gland or stuffing box housing 10 forming an annular chamber 12 in surrounding relationship to wash pipe 6. Housing 10 has a first end wall 14 having a bore 14A therethrough and a second end (partially shown) which is threaded as at 16 to receive a threaded follower 18. As seen, there is a second stuffing box assembly 8A which is substantially a mirror image of assembly 8. Positioned in the annulus in chamber 12 surrounding wash pipe 6 is an annular seal ring carrier 2 which is sealed against follower 18 by means of an O-ring 1. An annular lip type seal ring 3 carried by carrier 2 and partially nested in seal ring carrier 4 is of a type commonly referred to as a V-ring or Chevron ring and has an annular, radially inwardly extending seal lip 3A which sealingly engages wash pipe 6. Annular seal ring carrier 4 carries an second identical seal ring 3 which is also partially nested in a lantern ring or adapter 5 through which lubricant can be injected through a port 20 in the well known manner. A third, identical seal ring 3 is also carried by lantern ring 5 and is nested in an annular, axially facing groove 13 in end wall 14 of housing 10.


Referring now to FIG. 2, there is shown one embodiment of the packing stuffing box/gland assembly of the present invention. The stuffing box assembly of FIG. 2, shown generally as 22, includes a housing 24 having a cylindrical side wall 25, an end wall 28 and is threaded opposite end wall 28 as at 30 to receive a threaded follower 32. Housing 24 forms a chamber 26 through which extends a wash pipe 34, an annulus being formed between the OD of wash pipe 34 and the inner cylindrical surface 36 of sidewall 25 of housing 24. Disposed in the annulus is an O-ring 38 that provides sealing between a seal ring carrier 40 and threaded retainer 32. Seal ring carrier 40 has an annular, axially and radially facing notch 42 in which is received a V-type or Chevron seal ring 44 having an annular, radially inwardly extending sealing lip 46 and an annular, radially outer portion 47 that also forms a sealing lip. Seal ring 44 is also nested in an annular adapter 45. As seen, seal ring 44 is engaged by an annular seal ring spreader 48 which is spaced radially inwardly from seal ring carrier 40. An annular wave spring 50 abuts one end of seal ring spreader 48. A second, annular wave spring 52 is separated from wave spring 50 by an annular spacer 54, wave spring 52 being engaged by a second annular spacer 56. A keeper ring 57, which can be an O-ring, holds spacer 56 in position.


Adapter 45 engages a second annular, spacer 60 which in turn engages a wave spring 62 which is spaced from another wave spring 64 by annular spacer 66. Wave spring 64 in turn engages a second, annular seal ring spreader 66. A second O-ring keeper 65 holds spacer 60 in place. A second seal ring 68 is carried in an annular notch 70 of a second seal ring carrier 72, seal ring 68 having an annular, radially inwardly extending sealing lip 74 which is engaged by spreader 67 and an annular, radially outer portion 69 that also forms a sealing lip. The seal ring 68 is nested in a second annular adapter 76 which in turn is nested in end wall 28 of packing gland 24.


It will be appreciated that when threaded follower 32 is tightened such that it is moved in the direction of arrow A, wave springs 50, 52, 62 and 64 will all be compressed. In this regard, the sizing of the spacers, the seal ring carriers, adapters, etc. is such that when the wave springs are in the relaxed position, i.e., not under compression, their axial extent would be greater than as shown in FIG. 2 or 3. However, once the wave springs are compressed, because the other components of the sealing assembly are properly dimensioned, the desired amount of pre-load can be exerted by the spreaders, e.g., 48 and 67, (?)against the seal ring lips 46 and 74, respectively. In effect, the stored energy in the wave springs 50, 52, 62 and 64 will operatively exert a force upon spreaders 48 and 67 such that sealing lips 46 and 74 will be urged into sealing engagement with the OD of wash pipe 34. Thus, even if the sealing lips 46 and 74 become plastically deformed or yield to the point where they would no longer be in adjacent sealing engagement with wash pipe 34, the energy stored in the wave springs will force the spreaders 48 and 66 into sealing engagement with the sealing lips 46 and 74 to maintain fluid tight engagement with wash pipe 34.


As can be seen from FIG. 2, the radially inner lips, e.g., lips 46 and 74 of seal rings 44 and 68, respectively, have an axially facing, frustoconical surface that is engaged by a complimentary, frustoconical surface on seal ring spreaders 48 and 66, respectively. The frustoconical surfaces on the seal rings have their largest diameter radially outwardly, their smallest diameter being radially inwardly. Conversely, the frustoconical surfaces on the spreaders have their largest diameter radially outwardly and their smallest diameter radially inwardly. The net effect of this is to have a force vector which is substantially perpendicular or at least transverse to the axis of the wash pipe 34.


Turning now to FIG. 3 there is shown yet another embodiment of the present invention. The stuffing box assembly of FIG. 3 shown generally as 90 has a housing 92 with an end-wall 94 and forms a chamber 96 through which wash pipe 98 extends. In this regard, end-wall 94 has a bore 100 therein. Housing 92 is threaded as at 102 for threadedly receiving a follower 104. With wash pipe 98 in place as shown in FIG. 3, there is an annulus formed around wash pipe 98, a sealing assembly, as described below, being disposed in the annulus.


Positioned in the annulus surrounding wash pipe 98 is a sealing assembly having a seal ring carrier 106, seal ring carrier 106 having an axially extending annular skirt 108 and a radially inwardly extending annular flange 110. An O-ring 112 provides sealing between a threaded follower 104 and seal ring carrier 106. Skirt 108 and flange 110 cooperate to form an axially extending, radially opening recess 114. Received in recess 114 is a spacer 116 that is engaged by seal ring 118 having a radially inwardly extending, annular sealing lip 120. Seal ring 118 also has an annular, radially outwardly extending sealing lip 122. An annular spreader 124 engages sealing lip 120 in a manner described more fully hereafter. A wave spring 126 engages spreader 124. A second wave spring 128 is nested between flange 110 and a spacer 130.


The assembly shown in FIG. 3 is also provided with a seal ring carrier 132 having a bore 134 that is in register with a bore 136 through the wall of housing 92. Carrier ring 132 is generally L-shaped having an annular, axially extending leg 136 and an annular, radially inwardly extending leg 138. Received in the notch formed by legs 136 and 138 is a second seal ring 140, having an annular, radially inwardly extending sealing lip 14, seal ring 140, as shown, being nested in end-wall 94 of housing 91.


As in the case described in FIG. 2, since sealing lip 120 and spreader 124 have complimentary engageable frustoconical surfaces, when spreader 124 is urged toward sealing lip 120 by the springs 126 and 128 there is a resulting force vector generally perpendicular or at least transverse to wash pipe 98, thereby ensuring that sealing lip 120 is constantly urged radially inwardly against wash pipe 98.


The seal rings can be made from a large variety of materials which are wear and heat resistant. Non-limiting examples of materials which can be employed are PTFE alloys, high temperature plastics, rigid elastomer/rubber fabric composites, engineered plastics, and other materials that are capable of withstanding high temperatures and pressures but which can plastically yield or take a permanent set. Accordingly, the seal rings can be made of any plastic, elastomeric or composite materials which can withstand high temperatures, e.g., greater than about 300° F., and high pressures, e.g., greater than about 3,000 psi. The seal rings can be constructed in a variety of ways. Thus, the seal ring can be made of a single material, e.g., thermoplastic or thermosetting resin including such materials as nylon, polyesters, aramids, acrylics, glass, carbon and the like and can also incorporate reinforcements as, for example, a composite of a thermoplastic or thermosetting resin incorporating braided metal wire, fibrous materials such as fiberglass, carbon fibers, etc. Further, seal rings can be constructed such that the body of the seal and the sealing lip are made of one construction and there is a reinforcing heel bonded to the body of the seal to prevent extrusion. Such reinforcing or anti-extrusion sections are particularly desirable when the fluids being handled, e.g., drilling mud, contains abrasives or other solid materials.


As noted above, these more sophisticated materials and seal constructions for the most part have a tendency to plastically yield or take a permanent set when under load and/or high temperatures for extended periods of time and accordingly loose at least some of their sealing capabilities over time. However, the sealing assembly of the present invention compensates for this yield by utilizing the stored energy of the wave springs in combination with the seal ring spreaders to urge the sealing lips into sealing engagement with the wash pipe.


Although the seal ring is shown as being of the V- or Chevron type, the seal rings can have any cross-sectional configuration provided they have at least one annular, radially inwardly extending sealing lip which can sealingly engage the wash pipe in fluid-tight engagement and which can be urged radially inwardly under the action of the seal ring spreaders from force exerted by the wave spring(s).


In the description above, reference has been made to a seal ring carrier. The term carrier is intended to mean any body of whatever shape in or on which the seal rings can be nested, carried, positioned, housed or supported.


It will be appreciated that while two sealing assemblies of seal rings have been shown in FIG. 2, one or more such assemblies can be employed depending on the operating conditions. It will also be appreciated that while in each sealing assembly described above there are two wave springs, again depending upon the conditions of operation, one such wave spring would suffice obviating the necessity for certain spacers, e.g., spacers 54 and 66. Obviously, more wave springs can be employed if desired.


While the invention has been described with respect to wave springs, it will be appreciated that Belville springs and other annular-type springs can be used as well. It is also possible to employ compression-type coil springs, e.g., a compression-type coil spring having an ID greater than the OD of the wash pipe such that it can encircle the wash pipe or a series of small coil springs circumferentially arranged around the wash pipe and carried by a spring holder. However, washer-type springs such as Belville springs and wave springs are preferred because of more even force distribution exerted by such springs around their circumference.


While the invention has been specifically described with respect to a radially inwardly extending sealing lip, it will be appreciated, that the sealing lip could be radially outwardly extending. In circumstances where the sealing lip was radially outwardly extending, a seal ring carrier would be employed, albeit though in this circumstances seal ring carrier would be radially inwardly of the radially outwardly extending portion of the seal ring. Also, in cases where the sealing lip was radially outwardly extending, the seal ring spreader would be positioned radially outwardly of the seal ring carrier but would still serve the purpose of cooperating with a suitably disposed spring such as a wave spring, Belville spring, etc. to urge the radially outwardly extending sealing lip in a radially outwardly direction.


The seal ring spreaders can take many shapes. It is only necessary that the seal ring spreader be operatively engageable with the seal ring or a portion thereof, such that when an axial force is exerted on the portion of the seal ring spreader that engages the seal ring, it preferentially acts either on the radially inner portion of the seal ring or the radially outer portion of the seal ring. Stated differently, the seal ring spreader should be of a size and shape such that it operatively acts upon the seal ring to exert a greater force on one or the other of the radially inner portion of the seal ring or the radially outer portion of the seal ring when the spreader is biased towards the seal ring by the biasing members, e.g., the wave springs. It will, thus, be appreciated that various combinations of shapes of the seal ring and the seal ring spreader can be employed provided they cooperate to impart a force vector on the seal ring that urges either the outer portion of the seal ring in a generally radially outward direction or the inner portion of the seal ring in a generally radially inward direction.


In cases where both the outer and inner portions of the seal ring form sealing lips, i.e., an annular, radially outwardly extending sealing lip and an annular, radially inwardly extending sealing lip, then the spreader will be of a type that engages one or the other of the sealing lips preferentially with a greater force than any force that might be exerted on the other of the sealing lips, albeit minimal.


It is also to be understood that the fact that the seal ring spreader cooperates with the seal ring to selectively exert a greater force on either the radially inner portion or the radially outer portion does not preclude some engagement of the seal ring spreader with both the inner and outer portions, provided that a greater force is exerted on either the inner or outer portion of the seal ring relative to the other portion of the seal ring. Furthermore, the seal rings of the type used in the assemblies of the present invention, of their very nature, wear with time. Accordingly, it will be recognized that when a sealing assembly of the present invention is initially installed and, by way of example, if the seal ring spreader is exerting a greater force on an annular, radially inwardly extending sealing lip with essentially no force being exerted on the radially outer portion of the seal ring, whether that outer portion be another sealing lip or not, as the seal ring wears, the seal ring spreader may well engage the radially outer portion of the seal ring to some extent, albeit with still a lesser force than that exerted on the radially inwardly extending sealing lip.


While the invention has been described above with respect to sealing between a stuffing box and the wash pipe of a rotary drilling swivel, it is to be understood that it is not limited. The packing assembly can be used between any two relatively moveable bodies to effect fluid-type sealing between the bodies and is particularly applicable to environments which require that the seal ring be made of a material which can withstand high pressures, temperatures and is wear resistant but which has a tendency to undergo plastic yield or permanent set when under load, particularly for extended periods of time and/or at elevated temperatures.


Also, while the invention has been described with respect to a member, e.g., a wash pipe, extending through a housing, it will be apparent that the member could extend into the housing rather than through the housing.

Claims
  • 1. A sealing assembly for use in sealing between a housing and a member extending into said housing, said housing and said member being relatively rotatable comprising: an annular seal ring carrier; an annular seal ring carried by said carrier, said seal ring having an annular, radially outer portion and an annular, radially inner portion; an annular seal ring spreader operatively engaged with said seal ring; an elastic biasing member operatively engaged with said seal ring spreader; and an annular, adjustable follower, said spreader exerting a greater force on one of said radially inner or outer portions than the other of the said radially inner or outer portions of said seal ring when said spreader is biased toward said seal ring by said biasing member.
  • 2. The sealing assembly of claim 1 wherein said housing is fixed relative to said member and said seal ring carrier comprises an axially extending skirt and a radially inwardly projecting flange, said skirt and said flange cooperating to form a radially opening annular recess, said seal ring, said spreader and said biasing member being received in said recess.
  • 3. The sealing assembly of claim 2 wherein said radially inner portion of said seal ring comprises a radially inwardly extending sealing lip and said spreader exerts said greater force on said inner portion of said seal ring.
  • 4. The sealing assembly of claim 2 wherein there are a plurality of said biasing members.
  • 5. The sealing assembly of claim 3 wherein there are plurality of said biasing members.
  • 6. The sealing assembly of claim 3 wherein said radially inwardly extending sealing lip has an axially facing, frustoconical sealing lip surface and said spreader has an axially facing, frustoconical engagement surface, said frustoconical sealing lip surface and said frustoconical engagement surface being complimentary to one another, the smallest diameter of said frustoconical engagement surface being radially inwardly, the largest diameter of said frustoconical sealing lip surface being radially outwardly.
  • 7. The sealing assembly of claim 2 wherein said radially inner portion comprises a radially inwardly extending sealing lip having an axially facing, frustoconical sealing lip surface and said spreader has an axially facing, frustoconical engagement surface, said frustoconical sealing lip surface and said frustoconical engagement surface being complimentary to one another, the smallest diameter of said frustoconical engagement surface being radially inwardly, the largest diameter of said frustoconical sealing lip surface being radially outwardly.
  • 8. The sealing assembly of claim 1 wherein said housing is fixed relative to said member and said seal ring carrier has an axially and radially inwardly opening notch and said radially outer portion of said seal ring is received in said notch.
  • 9. The sealing assembly of claim 8 wherein said spreader and said biasing member are disposed radially inwardly of said carrier.
  • 10. The sealing assembly of claim 9 wherein there are a plurality of said biasing members.
  • 11. The sealing assembly of claim 8 wherein said radially inner portion of said seal ring comprises a radially inwardly extending sealing lip and said spreader exerts said greater force on said carrier portion.
  • 12. The sealing assembly of claim 11 wherein said sealing lip has an axially facing, frustoconical sealing lip surface and said spreader has an axially facing frustoconical engagement surface, said frustoconical sealing by surface and said frustoconical spreader surface being complimentary to one another, the smallest diameter of said frustoconical engagement surface being radially inwardly, the largest diameter of said frustoconical sealing lip surface being radially outwardly.
  • 13. The sealing assembly of claim 9 wherein there are a plurality of said biasing members.
  • 14. A stuffing box assembly for use in sealing between a fixed housing and a rotatable member extending into said housing, comprising: a housing having a bore for receipt of said rotatable member and forming a sealing assembly chamber; a sealing assembly received in said chamber, said sealing assembly comprising: an annular seal ring carrier having a bore therethrough, said bore in said seal ring carrier and said housing being in register; an annular seal ring carried by said carrier, said seal ring having an annular, radially outer portion and an annular, radially inwardly extending lip for sealingly engaging said rotatable shaft; an annular seal ring spreader operatively engaged with said seal ring; an elastic biasing member operatively engaged with said seal ring spreader; and an annular, adjustable follower selectively, axially moveable with respect to said housing, said spreader exerting a greater force on said sealing lip than said radially outer portion, when said spreader is biased towards said seal ring by said biasing member.
  • 15. The stuffing box assembly of claim 14 wherein said seal ring carrier comprises an axially extending skirt and a radially inwardly projecting flange, said skirt and said flange cooperating to form an annular recess, said seal ring, said spreader and said biasing member being received in said recess.
  • 16. The stuffing box assembly of claim 14 wherein said radially outer portion of said seal ring comprises a sealing lip.
  • 17. The stuffing box assembly of claim 14 wherein there are a plurality of said biasing members.
  • 18. The stuffing box assembly of claim 15 wherein there are a plurality of said biasing members.
  • 19. The stuffing box assembly of claim 14 wherein said radially inwardly extending sealing lip has an axially facing, frustoconical sealing lip surface and said spreader has an axially facing, frustoconical engagement surface, said frustoconical sealing lip surface and said frustoconical engagement surface being complimentary to one another, the smallest diameter of said frustoconical engagement surface being radially inwardly, the largest diameter of said frustoconical sealing lip surface being radially outwardly.
  • 20. The stuffing box assembly of claim 15 wherein said radially inwardly extending sealing lip has an axially facing, frustoconical sealing lip surface and said spreader has an axially facing, frustoconical engagement surface, said frustoconical sealing lip surface and said frustoconical engagement surface being complimentary to one another, the smallest diameter of said frustoconical engagement surface being radially inwardly, the largest diameter of said frustoconical sealing lip surface being radially outwardly.
  • 21. The stuffing box assembly of claim 14 wherein said carrier has an axially and radially inwardly opening notch and said radially outer portion of said seal ring is received in said notch.
  • 22. The stuffing box assembly of claim 21 wherein said spreader and said biasing member are disposed radially inwardly of said carrier.
  • 23. The stuffing box of claim 21 wherein there are a plurality of said biasing members.
  • 24. The stuffing box assembly of claim 22 wherein sealing lip has an axially facing, frustoconical sealing lip surface and said spreader has an axially facing frustoconical engagement surface, said frustoconical sealing by surface and said frustoconical spreader surface being complimentary to one another, the smallest diameter of said frustoconical engagement surface being radially inwardly, the largest diameter of said frustoconical sealing lip surface being radially outwardly.
  • 25. The stuffing box assembly of claim 22 wherein there are a plurality of said biasing members.
  • 26. The sealing assembly of any of claims 1, 4, 5, 10 or 13 wherein said biasing member(s) comprises a wave spring(s).
  • 27. The stuffing box of any of claims 14, 17, 18, 23 or 25 wherein said biasing member(s) comprises a wave spring(s).
Provisional Applications (1)
Number Date Country
60736891 Nov 2005 US