End connector for high pressure reinforced rubber hose

Abstract

A swage fitted end connector for high pressure large diameter reinforced flexible rubber hose utilizing sine-wave locking of the reinforcement and particularly suited to the petrochemical and drilling industries. Two embodiments of the connector for use with wire reinforced thin internal tube hose are disclosed: one with a diameter of 3-inches and for burst pressures up to 20,000 psi and the other for a diameter of 5-inches and for burst pressures up to 18,000 psi. All of the connectors will withstand the rated burst pressure of the hose without pumping off or leaking thus any hose that utilizes the device will fail before the connector pops off the hose. The connectors are designed to meet or exceed the new API temperature ranges and new API flexible specification levels which became effective in October 2006.

Claims

1. An end connector for permanent attachment to reinforced hose having reinforcement, comprising: a stem having a coupler end, a hose receiver end; a ferrule attached to the stem at an attachment point adjacent the coupler end, the stem and ferrule having a cavity located therebetween, extending along a length of the end connector, configured to receive an end of a reinforced hose therein, and divided into: at least two gripping zones extending from adjacent a point where the ferrule is attached to the stem toward the hose receiver end, the at least two gripping zones including: a first gripping zone located adjacent the point where the ferrule is attached to the stem and having a first plurality of flutes and lands formed in the stem, a second plurality of flutes and lands formed in the ferrule, wherein the first gripping zone further includes an expansion zone located adjacent the attachment point and an expansion zone located adjacent the attachment point and between the attachment point and the first plurality, wherein a distance between each of the flutes of the first plurality in the stem is different from a distance between each of the flutes of the second plurality, as taken along a longitudinal central axis of the end connector; and a second gripping zone located nearer the hose receiver end than the first gripping zone and having a third plurality of flutes and lands formed in the stem, wherein a distance between each of the flutes of the third plurality is different from the distance between each of the flutes of the first and second plurality, as taken along the central axis, and having a fourth plurality of flutes and lands formed in the ferrule, wherein an axial distance between each of the flutes of the fourth plurality is different from an axial distance between each of the flutes of the second plurality, as taken along the central axis.

2. The end connector of claim 1, wherein the number of flutes and landings or the size of the flutes and lands of the first plurality is different from the number of flutes and lands or the size of the flutes and lands of the second plurality.

3. The end connector of claim 1, wherein the number of flutes and lands or the size of the flutes and lands of the third plurality is different from at least one of the first and second plurality.

4. The end connector of claim 3, wherein the third plurality of flutes and lands are different in number or the size of the flutes and lands of both the first and second plurality of flutes and lands.

5. The end connector of claim 1, wherein the different configuration between the third and fourth plurality of flutes and lands is a difference between the number of or the size of the flutes and lands.

6. The end connector of claim 1, wherein the first gripping zone further includes a reinforcement liner stop formed in the stem and located nearer the expansion zone than the first plurality of flutes and lands.

7. The end connector of claim 6, wherein the first plurality of flutes and lands is located between the reinforcement liner stop and an inner liner stop formed in the stem located nearer the hose receiver end than the first plurality of flutes and lands.

8. A high pressure reinforced hose assembly, comprising: an end connector having a coupler end and a hose receiver end, comprising: a ferrule attached to a stem at an attachment point adjacent the coupler end, the stem and ferrule having a cavity located therebetween, extending along a length of the end connector, configured to receive an end of a reinforced hose therein, and divided into: at least two gripping zones extending from adjacent a point where the ferrule is attached to the stem toward the hose receiver end, the at least two gripping zones including: a first gripping zone located adjacent the point where the ferrule is attached to the stem and having a first plurality of flutes and lands formed in the stem, and a second plurality of flutes and lands formed in the ferrule, wherein a distance between each of the flutes of the first plurality in the stem is different from a distance between each of the flutes of the second plurality, as taken along a longitudinal central axis of the end connector, and wherein the first gripping zone includes an expansion zone located adjacent the attachment point and located between the attachment point and the first plurality of flutes and lands; and a second gripping zone located nearer the hose receiver end than the first gripping zone and having a third plurality of flutes and lands formed in the stem, wherein a distance between each of the flutes of the third plurality is different from the distance between each of the flutes of the first and second plurality, as taken along the central axis, and having a fourth plurality of flutes and lands formed in the ferrule, wherein a distance between each of the flutes of the fourth plurality is different from the distance between each of the flutes of the second plurality, as taken along the central axis; and a section of high pressure reinforced hose having first and second ends, an innermost liner, and one or more reinforcement layers located over the innermost liner, the first end being received within the cavity such that a portion of the one or more reinforcement layers engages a reinforcement liner stop formed in the stem and located nearer the expansion zone than the first plurality of flutes and lands, the hose extending into the expansion zone and the innermost liner engaging an inner liner stop formed in the stem located nearer the hose receiver end than the reinforcement liner stop.

9. The end connector of claim 8, wherein the number of flutes and lands or the size of the flutes and lands of the first plurality is different from the number of flutes and lands or the size of the flutes and lands of the second plurality.

10. The end connector of claim 8, wherein the number of flutes and lands or the size of the flutes and lands of the third plurality is different from at least one of the first and second plurality.

11. The end connector of claim 10, wherein the third plurality of flutes and lands are different in number or the size of the flutes and lands of both the first and second plurality of flutes and lands.

12. The end connector of claim 8, wherein the different configuration between the third and fourth plurality of flutes and lands is a difference between the number of or the size of the flutes and lands.

13. The end connector of claim 12, wherein ends of the first plurality of flutes and lands are defined by the reinforcement liner stop and the inner liner stop.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows the cross-section of a typical cable reinforced flexible rubber hose.

(2) FIG. 2 shows a cross-sectional view of the current state of the art end standard connector with an NTP termination. (This is an old-style connection in use for many decades.)

(3) FIG. 3A shows a cross-sectional view of the ferrule used in the advanced current state of the art ‘double lock sine-wave’ end connector. (The ‘double lock sine-wave’ end connector has been in use for the past five years.)

(4) FIG. 3B is a cross-section taken at 3B.

(5) FIG. 3C is a cross-section taken at 3C.

(6) FIG. 4A shows a cross-sectional view of the stem used in the advanced current state of the art ‘double lock sine-wave’ end connector.

(7) FIG. 4B is a cross-section taken at 4B.

(8) FIG. 4C is a cross-section taken at 4C.

(9) FIG. 4D is a cross-section taken at 4D.

(10) FIG. 5A shows the cross-sectional view of the ferrule used in the first embodiment of the instant invention, being a general improvement to the ‘double lock sine-wave’ connector. (Note the similarities between FIGS. 3A and 5A.)

(11) FIG. 5B is a cross section taken at 5B.

(12) FIG. 5C is a cross-section taken at 5C.

(13) FIG. 6A shows the cross-sectional view of the stem used in the first embodiment of the instant invention, being a general improvement to the ‘double lock sine-wave’ connector and forming a single lock sine wave within the overall device. (Note the dissimilarities between FIGS. 4A and 6A.)

(14) FIG. 6B is a cross-section taken at 6B.

(15) FIG. 6C is a cross-section taken at 6C.

(16) FIG. 7 is a sketch of the first embodiment of the improved end connector taken about the longitudinal center line showing the ferrule joined to the stem.

(17) FIG. 8A is an engineering drawing from the side taken about the longitudinal center line of the ferrule of the second and preferred embodiment of the improved end connector.

(18) FIG. 8B is a cross-section taken at 8B.

(19) FIG. 8C is a cross-section taken at 8C.

(20) FIG. 9A is an engineering drawing from the side taken about the longitudinal center line of the stem of the second and preferred embodiment of the improved end connector.

(21) FIG. 9B is a cross-section taken at 9B.

(22) FIG. 9C is a cross-section taken at 9C.

(23) FIG. 10 is a sketch of the second and preferred embodiment of the improved end connector taken about the longitudinal center line showing the ferrule joined to the stem. This figure also defines certain terms used in the disclosure and the gripping zones used in the claims.

(24) FIG. 11 shows the second and preferred end connector immediately before the “double-skived” high pressure reinforced hose is inserted into the end connector. Note that inner tube has been removed as well as the outer cover to expose the reinforcement.

(25) FIG. 12 shows the second and preferred end connector immediately after the “double-skived” high pressure reinforced hose is inserted into the end connector and before swaging.

(26) FIG. 13 shows the second and preferred end connector with the “double-skived” high pressure reinforced hose inserted into the end connector and after swaging is complete.

(27) FIG. 14 gives a table of connector dimensions for the second embodiment in the British System of Units.

(28) FIG. 15 gives a skiving table for the second embodiment in the British System of Units.

DESCRIPTION OF THE EMBODIMENTS

(29) FIG. 1 shows a standard weight schedule D cable reinforced hose. Schedule E hose will generally have 4 interlocking reinforcing plys. Not shown is a cross-section of a European light weight wire reinforced hose; however, it would be similar to FIG. 1, except there would be 6 interlocking wire plys and the inner tube would comprise one thin layer of rubber.

(30) The ferrule of the first embodiment of the instant invention is shown, in cross-section, in FIG. 5 and is machined from 4″×0.337 W Schedule 80 Pipe. [It is difficult to give metric equivalents.] The ferrule of the second embodiment is shown, in cross-section, in FIG. 8 and is machined from 9.00×0.750 wall mechanical tube (DOM). [It is difficult to give metric equivalents.] One end (the end that will be welded to the stem) is placed in a Roll Die and compressed to form a narrower neck as shown at the far left in FIGS. 5 and 8. The inside of the ferrule is machined to produce a series of lands and flutes (a total of six are shown in FIGS. 5A-5C with a total of ten being shown in FIGS. 8A-8C).

(31) In FIGS. 5A-5C the first embodiment, the lands all have the same radial height measured from the axial center line of the ferrule being 4.03.sup.φ. The first and second flutes (counting from the hose end of the ferrule) have a radial height of 3.88.sup.φ, the third flute has a height of 3.86.sup.φ and the final three flutes have a height of 3.83.sup.φ. FIGS. 8A-8C, being the second embodiment, is somewhat different and will be described in detail later paragraphs. In both embodiments the flutes are NOT axially spaced equidistantly along the ferrule. This is because it is known that as the ferrule is swaged (beginning from the hose end), the ferrule will move axially towards the hose end of the fitting until the reinforcement locks between the ferrule and the stem. The actual lock will not start to occur until the swage is about midway along the ferrule. Up to this point the inner tube and hose is free to move axially away from the termination end of the fitting. When lock occurs, all movement of the inner tube and hose will be towards the termination end of the fitting.

(32) Simple mechanical calculations based on material properties and the degree of swaging that will be applied allow the designer to calculate the flute spacing so that after the fitting is swaged to the hose, the bumps of the stem will fall approximately midway inside the lands of the ferrule. The manner in which the final position of the bumps at approximately midway within the lands is the key to this device and how it obtains the sine-wave lock between the reinforcement and the ferrule.

(33) The dimensions of the land and flute heights must not be read as a restriction but as an example. Similarly, the flute spacing shown must not be read as a restriction but as an example. Under some circumstances (larger diameter hose), it may be necessary to adjust these dimensions so that they vary with distance from the hose end forming an overall slope.

(34) At the end of the connector nearest the hose, the inside diameter of the ferrule is increased so that when the ferrule is swaged minimum pressure will be exerted on the rubber outer covering. The hose end is rounded as shown.

(35) The stem of the first embodiment of the instant invention is shown, in cross-section, in FIGS. 6A-6C and is machined from 3″×437 W Schedule SMLS Pipe. Six “bumps” are 0.06-inches and are equidistantly machined in the stem. As explained above, the relative position of the bumps on the stem and the lands on the associated ferrule is critical to forming the sine-wave lock between the ferrule and the reinforcement. Again, the dimensions given must not be construed as a restriction but as an example. This is because this dimension will vary with the size of the fitting and the type of reinforced hose. Any engineer with knowledge of materials and swaging may readily make adjustments to this disclosure for varying sizes of fittings, hose, hose type and materials that could be used in the manufacturer of the fitting. In fact the size of the bumps should be chosen by trial and error to have a minimum height just so that the bumps cause the sine-wave lock of the reinforcement plys in the ferrule. The best way to obtain the correct dimensions and spacing of flutes, lands, and bumps to by trial and error. Calculations will help.

(36) The ferrule of FIGS. 5A-5C is welded to the stem of FIGS. 6A-6C at the ledge on the stem and the complete assembly (being the first embodiment) is shown in FIG. 7. The weld is carefully inspected to assure quality. If the completed fitting is to be used in H.sub.2S service, the fitting must be heat treated to reduce the possibly of hydrogen-sulphide stress cracking.

(37) The first embodiment fitting is permanently attached to a reinforced high pressure rubber hose using industry standard techniques—yet another plus for the device. The outer covering is usually skived to expose the reinforcement. The axial length of the skive is set by the axial length of the ferrule: one must make certain that approximately ½-inch of the outer cover falls under the hose end of the ferrule before swaging. The hose is then carefully placed within the cavity formed between the ferrule and the stem to approximately ½-inch from the far end of the cavity. This space allows for expansion of the hose during the swaging operation.

(38) As explained earlier, the swaging operation starts at the hose end of the fitting and moves axially along the fitting to the termination. As the ferrule is swaged, it moves radially inward towards the stem and axially outward towards the hose. As the ferrule moves axially inward, the stem bumps act to displace all plys of the reinforcement into the lands of the ferrule. At approximately midway along the ferrule (during swaging) the reinforcement at the hose end will lock in the form of a sine wave (following the shape of the ferrule). As the swaging operation continues, the ferrule will move axially away from the hose end of the fitting along with the hose. The sine wave lock progressively moves with the swage until swaging is stopped just past the last flute—away from the hose end. The ferrule will actually expand radially about the stem resulting in a volume which receives the excess rubber from the hose.

(39) It must be understood that there is no mechanical lock between the inner tube of the hose and the stem in the first embodiment. The mechanical lock is found between the lands and flutes of the ferrule in the form of a modified sine-wave and the reinforcement. During the course of testing to meet the newer API standards it was found that the first embodiment did not stand up to the new API standards for temperature and flexibility, hence the device was further enhanced to result in the second embodiment. However, the first embodiment of the device is still an improvement to the double-lock Baldwin device and adds to the art.

(40) Now let us examine the second and preferred embodiment which is a modification of the first embodiment necessitated by the new API standards for rotary hose involving both temperature and flexibility. As explained in the background section of this patent, the higher temperature causes the inner tube of a reinforced hose to more or less turn to mush which results in two problems. First, the lock between the reinforcement and the connector fails because the rubber turns to jelly, and, second, a swaged connector slides off the hose. In the case of both a swaged connector and a built-up hose assembly, the mushy (due to temperature) inner hose leaks and fluid comes out between the hose and the connector. Both the tendency for a swaged connector to come loose and the tendency for both a swaged connector and a build-up hose connector to leak are exacerbated by the flexibility standard. Hence the concept of the first embodiment was expanded to solve the problem.

(41) FIGS. 8A-8C show the ferrule for the second and preferred embodiment. There are essentially three sets of flutes (bumps) and lands (grooves) and a termination gripping section. Starting at the end of the connector furthermost away from the hose (the left side in the FIG. 8A), there is a ‘zero’ or expansion area, followed by the first set of four flutes all having the same radial height measured from the axial center line of the ferrule being 7.52.sup.φ with the lands between the first set of flutes having a radial depth of 7.78.sup.φ. The second set of flutes (two) has the same radial height and the third set of flutes (four) being 7.50.sup.φ and the land between these two flutes has a radial depth of 7.76.sup.φ. The lands between the third set of flutes has a radial depth of 8.03.sup.φ. Finally the there is a termination flute that is slopped and tappers off from a radial height of 7.67.sup.φ towards the end of the connector that touches the outer jacket of the hose. As stated earlier, in both embodiments the flutes are NOT axially spaced equidistantly along the ferrule.

(42) The stem of the second embodiment of the instant invention is shown, in cross-section, in FIGS. 9A-9C, and is machined from 6⅝-inch O.D. mechanical tubing—Gr. 4130 [again it is difficult to give a metric equivalent]. Starting from the end furthermost from the hose (the left side in the Figure) there are two longitudinal flat areas having a relative height of 6.413.sup.φ and 5.46.sup.φ. It will be seen that the first of these two areas acts in conjunction with the ferrule after and during swaging to form an expansion zone (zone 1). The second area acts as a stop to the reinforcement as the hose is placed within the complete connector as well as allowing some movement of the reinforcement during swaging until the swage operation reaches this zone at which the ferrule and stem will crimp about the reinforcement to form a first gripping zone (zone 2) when the connector is swaged.

(43) This is followed by four flutes also having a relative height of 5.46.sup.φ. It will be seen that this set of flutes and lands will align with the first set of flutes and lands of the ferrule after swaging to form a second gripping zone (zone 3). The lands between these flutes have a relative depth of 5.33.sup.φ. The last flute is somewhat different and is followed by another (third) longitudinal flat area having a relative height of 4.98.sup.φ. It will be seen that this area will align with the second set of flutes and lands in the ferrule to form a third gripping zone (zone 4), which will act somewhat like a double crimp when the connector is swaged. (Note the backward slope in the transition between the flute and the flat spot—this is not necessary but will be explained.) This is followed by a series of four bumps having a height of 4.98.sup.φ with lands between the bumps having a relative depth of 4.88.sup.φ. It will be seen that these bumps will align with the third set of flutes and lands in the ferrule to form a sinusoidal like fourth gripping zone (zone 5).

(44) There is then a gentle transition back to a flat area having a relative height of 4.98.sup.φ. It will be seen that this transition acts in conjunction with the ferrule to form a stress reduction and termination zone (zone 6). As explained above, the relative position of the bumps and flutes on the stem and the lands on the associated ferrule is critical to forming the sine-wave lock between the ferrule, the reinforcement, and the stem.

(45) Again, the dimensions given must not be construed as a restriction but as an example. This is because this dimension will vary with the size of the fitting and the type of reinforced hose. Any engineer with knowledge of materials and swaging may readily make adjustments to this disclosure for varying sizes of fittings, hose, hose type and materials that could be used in the manufacturer of the fitting. In fact the size of the bumps should be chosen by trial and error to have a minimum height just so that the bumps cause the sine-wave lock of the reinforcement plys in the ferrule. The same techniques used in the first embodiment to obtain the correct height, depths and spacing must be employed, i.e., trial and error.

(46) The ferrule of FIGS. 8A-8C is welded to the stem of FIGS. 9A-9C at the ledge on the stem and the complete assembly (being the second embodiment) is shown in FIG. 10. The weld is carefully inspected to assure quality. If the completed fitting is to be used in H.sub.2S service, the fitting must be heat treated to reduce the possibly of hydrogen-sulphide stress cracking.

(47) The second embodiment fitting is permanently attached to a reinforced high pressure rubber hose using highly modified industry standard techniques. First the outer covering is skived to expose the reinforcement. The axial length of the outer skive is set by the axial length of the ferrule: one must make certain that approximately ½-inch of the outer cover falls under the hose end of the ferrule before swaging. Second, the inner carcass, which is essentially the inner tube, is skived to expose the reinforcement (not a usual procedure in rotary hose). The axial length of the internal skive is set by the axial length of the fitting between points “B” and “D” (see FIG. 10).

(48) The hose is then carefully placed within the cavity formed between the ferrule and the stem to approximately where the reinforcement rests against point “B,” which acts as a stop against the reinforcement, and the inner tube rests against point “D”, thus assuring proper placement of the hose within the connector. The space between points “A” and “B” allows for expansion of the hose and or the reinforcement during the swaging operation.

(49) As explained earlier, the swaging operation starts at the hose end of the fitting and moves axially along the fitting to the coupling end. As the ferrule is swaged, it moves radially inward towards the stem and axially outward towards the hose. As the ferrule moves axially inward, the stem bumps act to displace all plys of the reinforcement into the lands of the ferrule. At approximately point “D” within the connector (during swaging) the reinforcement at the hose end will lock in the form of a sine wave (following the shape of the ferrule). As the swaging operation continues past point “D” toward point “A”, the ferrule will move axially away from the hose end of the fitting along with the hose. The sine wave lock between the stem, reinforcement and ferrule progressively moves with the swage until swaging is stopped just past the last flute near point “B”. Sometimes the swaging will continue to a point between points “B” and “A”. The ferrule will actually expand radially about the stem resulting in a volume which receives the excess reinforcement from the hose (zone 1).

(50) It must be understood that there is a mechanical lock between the stem and the ferrule between points “B” and “C” as a ‘crimp’ (the first gripping zone—zone 2) and then there is the important mechanical lock between points “C” and “D” in the form of a modified sine-wave (zone 3). It is this sinusoidal lock (the second gripping zone) that holds the connector to the hose. There is then a further mechanical lock found between points “D” and “E” being the third gripping zone formed between the second set of flutes and lands on the ferrule and the third flat area of the stem (zone 4).

(51) The set of bumps located between points “E” and “F” on the stem interact with the third set of flutes and lands on the ferrule to form a fourth gripping zone which results in the form of a modified sine-wave between the inner carcass and the reinforcement (zone 5). It is this lock that stops the fluid from leaking around the stem of the connector and to the outside of the hose when the inner tube turns mushy due to high temperatures. Essentially this sinusoidal lock is the same as the first embodiment.

(52) Finally, the transition area between point “F” and the end of the connector interacts with the termination flute of the ferrule to form a fifth gripping and termination zone (zone 6). The process is illustrated in FIGS. 11 through 13. It is possible to skip the second skive (i.e., the section of hose that falls in zone 5)—as in the first embodiment; however, the probability of fluid leakage will now be present.

(53) Now let us try to understand the operation of the swaged connector when the hose is subjected to high temperature fluids which tend to cause the inner tube to become mushy (i.e., the inner tube looses strength and turns to jelly). The lip at point “D” inhibits the passage of mushy rubber back towards the open end of the connector. Similarly the corresponding slopped sections of the ferrule and stem (sloping towards each other when swaged) at the hose end of the connector in conjunction with the double crimp lock between points “D” and “E” and the sine-wave lock between point “E” and “F” of the connector serve to retain the mushy inner carcass thereby preventing fluid leak from the connector. Finally, because of the sine-wave lock between the reinforcement, the stem, and the ferrule (between points “C” and “D”); the connector cannot be pumped-off from the hose. The pump-off force is transferred from the first connector (at one end of the hose) to the reinforcement through the hose (the actual reinforcement) and onto the second connector (at the other end of the hose). Providing the reinforcement is not damaged (the point of the sine-wave lock), then the reinforcement will not fail within the connector. However, any failure will occur in the hose which makes the whole assembly much safer.

(54) The inventive step is the realization that a series of bumps in the stem could replace the original double sine wave lock of the Baldwin et al device. Furthermore, this device no longer requires expansion of the stem and no longer requires a step in the stem to reduce column buckling. Furthermore, machining is simplified and the number of elements (double lock sine) is reduced to a single lock sine wave. The second embodiment of the device is an improvement to the double-lock Baldwin device, adds to the art, and meets the new API specifications.

(55) It must be remembered that all dimensions given in this disclosure are for example and must not be read a limitation because dimensions will change with hose diameter and pressure ratings. The number of corresponding flutes and lands will be set by the diameter of the hose and the pressure rating and thus are subject to change. Two examples have been given, one for three inch hose (the first embodiment) and one for five inch hose (the second embodiment). Two tables are shown in FIGS. 14 and 15 which give the fundamental dimensions for the second embodiment connector, as well as details as to skive dimensions. The techniques described in this disclosure will allow a person skilled in the manufacturing art to duplicate the two embodiments for various diameters and pressure ratings.

(56) A high pressure rotary hose assembly can readily be assembled from a specified length of specified high pressure hose from either of the two embodiments disclosed above by the hose manufacturer or a local distributor. As the specifications increase in temperature and flexibility requirements the hose assembly would be swaged from the second and preferred embodiment.