GB2587383A

GB2587383A - Pipe coupling arrangement

Info

Publication number: GB2587383A
Application number: GB1913866.8A
Authority: GB
Inventors: Goichman Tal; Apter Avidor Ziv
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-09-26
Filing date: 2019-09-26
Publication date: 2021-03-31
Also published as: GB201913866D0

Abstract

A pipe coupling arrangement, comprising: A first and second pipe ends 12 and 16; A pipe coupling assembly 50, including: First and second flanges, said flanges having an inner flange surface (e.g. 52) forming a first opening (e.g. 53) receiving said metal pipe end; At least one gasket 64 radially enveloping an outer surface of said pipe ends; a gasket housing 61 including at least one gasket housing element (e.g. 62 or 66); At least a first wedge 71 disposed around said first pipe end; and at least a second wedge 76 disposed around said second pipe end; and; An axial closure arrangement 82 for axially closing a distance between said first and second flanges; Wherein said at least first wedge and said at least second wedge each have: A sloped surface (73); A radially-inward wedge surface (92) having at least one protruding element (95) protruding radially inwards; Whereby, as said axial closure arrangement is closed in a tightening mode, each of said first and second inner flange 52 surfaces envelops said respective sloped outer surface and delivers a radially-inward force thereto such that said at least one protruding element is embedded in said outer surface of said pipe ends.

Description

PIPE COUPLING ARRANGEMENT

FIELD OF THE INVENTION AND BACKGROUND

The present invention relates to pipe couplings, and more particularly, couplings for pipeline assemblies employed for conveying liquids and gasses 5 under high pressure.

The most common way to connect for conveying fluids under high pressure (e.g., above 60 bar, and often, above 100 bar) is by using pipe couplings requiring pipe ends having circumferential grooves disposed in the outer wall thereof.

Assembly of the coupling on the pipe ends is performed in a way that ensures that parts of the couplings are well inserted into the grooves. Thus, internal pressure multiplied by pipes section area produces tearing axial forces that are much smaller than shear force that the pipe groove can withstand. The external seals that are assembled in the coupling and pressed against the outer diameter of the pipe do not feel the axial or bending forces and moments. The idea behind this type of coupling is that the reaction forces against pressure induced axial forces come from shear force between the coupling protrusion and the groove of the pipe.

Examples of such commercially available couplings are Quickvic® and Shurjoint® couplings of Victaulic®. While this method is most widely used, as it produces reliable results in terms of forces against high pressure, it is disadvantageous in that it requires a preliminary, labor-intensive groove making procedure, using a dedicated machine and requiring physical support for the typically long heavy pipes to be grooved. Moreover, any mistake in groove position requires cutting and remaking the groove or using a new pipe element. The pre-grooving process may be a major component of the overall cost of the piping project.

The present inventors have recognized a need for improved pipe coupling arrangements for holding metal cylindrical pipe ends of a piping structure in fixed end-to-end relationship, particularly at high fluid pressures.

SUMMARY OF THE INVENTION

According to teachings of the present invention there is provided a pipe coupling arrangement for holding metal cylindrical pipe ends of a piping structure in fixed end-to-end relationship, the pipe coupling arrangement comprising a pipe coupling assembly including: (i) first and second flanges, the first flange having a first inner flange surface forming a first opening dimensioned to receive a first metal, cylindrical pipe end; the second flange having a second inner flange surface forming a second opening dimensioned to receive a second metal, cylindrical pipe end; (ii) a gasket arrangement for disposing between the first and second flanges, the gasket arrangement including at least one gasket dimensioned to radially envelop an outer surface of the first and second metal, cylindrical pipe ends, and adapted to seal therebetween; and a gasket housing including at least one gasket housing element, the gasket housing dimensioned to radially and axially contain the at least one gasket; (iii) at least a first wedge or wedge element dimensioned to envelop the first metal, cylindrical pipe end; and at least a second wedge or wedge element dimensioned to envelop the second metal, cylindrical pipe end; and (iv) an axial locking arrangement for axially maintaining the first and second flanges in a fixed relative position, in an assembled, operative mode; the axial locking arrangement optionally including at least a portion of an axial closure arrangement for axially closing a distance between the first and second flanges wherein at least one of the at least first wedge or wedge element and the at least second wedge or wedge element has: (i) a sloped outer surface sloping radially outwards, in the assembled, operative mode, towards an axial center of the gasket housing, and (ii) a radially-inward disposed wedge surface of the wedge or wedge element having at least one protruding element protruding radially inwards; and wherein, in the assembled, operative mode, each of the first and second inner flange surfaces is sloped radially outwards towards the axial center of the gasket housing; whereby, in a tightening mode, in which the first and second metal, cylindrical pipe ends are respectively disposed within the first and second openings, and within the gasket, and the distance between the first and second flanges is axially closed or tightened by the axial closure arrangement, each of the first and second inner flange surfaces envelops the respective sloped outer surface and delivers a radially-inward force thereto, such that the at least one protruding element of each of the first and second wedges or wedge elements is thrust in a radially-inward direction, such that in the assembled, operative mode, with the first and second metal, cylindrical pipe ends respectively snugly fitting radially within the first and second wedges or wedge elements, the at least one protruding element of each of the first and second wedges or wedge elements is respectively embedded in the outer surface of the first and second metal, cylindrical pipe ends, to achieve an anchored position.

According to further teachings of the present invention there is provided a pipe coupling arrangement holding metal cylindrical pipe ends of a piping structure in a fixed end-to-end relationship, the pipe coupling arrangement comprising, in an assembled, operative mode: (a) a first metal, cylindrical pipe end; (b) a second metal, cylindrical pipe end; and (c) a pipe coupling assembly including: (i) first and second flanges, the first flange having a first inner flange surface forming a first opening receiving the first metal, cylindrical pipe end; the second flange having a second inner flange surface forming a second opening receiving the second metal, cylindrical pipe end; (ii) a gasket arrangement disposed between the first and second flanges, the gasket arrangement including at least one gasket radially enveloping an outer surface of the first and second metal, cylindrical pipe ends, and sealing therebetween; and a gasket housing including at least one gasket housing element, the gasket housing radially and axially containing the at least one gasket; (iii) at least a first wedge disposed around the first metal, cylindrical pipe end; and at least a second wedge disposed around the second metal, cylindrical pipe end; and (iv) an axial locking arrangement for axially maintaining the first and second flanges in a fixed relative position; wherein the at least the first wedge and the at least the second wedge each have: (i) a sloped, radially-outward surface sloping radially outwards towards an axial center of the gasket housing, and (ii) a radially-inward wedge surface having at least one protruding element protruding radially inwards; wherein a hardness (e.g., a Rockwell C hardness) of the at least one protruding element exceeds a hardness of a respective outer surface of the metal, cylindrical pipe end; and wherein each of the first and second inner flange surfaces is sloped in radially outwards towards the axial center of the gasket housing; whereby, in a tightening mode, as an axial closure arrangement for axially closing a distance between the first and second flanges is closed or tightened, each of the first and second inner flange surfaces envelops the respective sloped outer surface and delivers a radially-inward force thereto, such that the at least one protruding element of each of the first and second wedges or wedge elements is embedded in the outer surface of the first and second metal, cylindrical pipe ends, to achieve an anchored position.

According to further features in the described preferred embodiments, the pipe coupling arrangement includes at least a portion of the axial closure 20 arrangement.

According to further features in the described preferred embodiments, the pipe coupling arrangement includes the axial closure arrangement.

According to further features in the described preferred embodiments, the axial locking arrangement includes a least a portion of the axial closure 25 arrangement.

According to further features in the described preferred embodiments, the axial locking arrangement includes the axial closure arrangement.

According to further features in the described preferred embodiments, the axial closure arrangement has at least one threaded element adapted to pass through at least one opening in each of the first and second flanges, and includes threading complementary to the at least one threaded element for axially closing a distance, when rotated, between the first and second flanges.

According to still further features in the described preferred embodiments, in the tightening mode, the at least a first wedge or wedge element is axially fixed with reference to the first metal, cylindrical pipe end.

Typically, the at least a second wedge or wedge element is axially fixed 10 with reference to the second metal, cylindrical pipe end.

According to still further features in the described preferred embodiments, in the tightening mode, the at least a first wedge or wedge element (and typically the at least a second wedge or wedge element) is axially fixed with respect to the gasket housing.

According to still further features in the described preferred embodiments, in the tightening mode, an internal axial force of the first flange (in an internal axial direction towards the gasket housing) is converted into substantially solely radial motion of the first wedge or wedge element.

According to still further features in the described preferred embodiments, 20 in the tightening mode, an internal axial force of the second flange (in an internal axial direction towards the gasket housing) is converted into substantially solely radial motion of the second wedge or wedge element.

According to still further features in the described preferred embodiments, in the anchored position, the first flange (and typically also the second flange) and the at least one gasket housing are axially spaced apart.

According to still further features in the described preferred embodiments, in the anchored position, the first wedge or wedge element (and typically also the second wedge or wedge element) and the gasket are axially spaced apart.

According to still further features in the described preferred embodiments, 5 the radially-inward force delivered by the first (and typically also the second) inner flange surface is exerted over at least 50%, at least 60%, at least 70%, or at least 80% of a circumference of the sloped outer surface.

According to still further features in the described preferred embodiments, the radially-inward force delivered by the first (and typically also the second) 10 inner flange surface is exerted over at least 95% of a circumference of the sloped outer surface.

According to still further features in the described preferred embodiments, the span of the at least one protruding element encompasses at least 50% of an outer circumference of a respective pipe end of the first (and typically also the second) metal, cylindrical pipe end.

According to still further features in the described preferred embodiments, the span of the at least one protruding element encompasses at least 80% of the outer circumference.

According to still further features in the described preferred embodiments, 20 the span of the at least one protruding element encompasses at least 120% of the outer circumference.

According to still further features in the described preferred embodiments, the span of the at least one protruding element encompasses at least 150% of the outer circumference.

According to still further features in the described preferred embodiments, the pipe coupling assembly is disposed on an ungrooved portion of the first metal, cylindrical pipe end and typically, on ungrooved portions of both first and second metal, cylindrical pipe ends.

According to still further features in the described preferred embodiments, at least one of (and typically both of) the first and second metal, cylindrical pipe 5 ends is ungrooved.

According to still further features in the described preferred embodiments, the axial closure arrangement is adapted to close the distance between the first and second flanges in a solely linear or substantially solely linear fashion.

According to still further features in the described preferred embodiments, the at least one protruding element of each of the first and second wedges is sufficiently embedded in the outer surface of the first and second metal, cylindrical pipe ends such that the pipe coupling arrangement maintains the anchored position for a time period of at least 1 hour, at least 7 days, or at least one year at a fluid pressure of 100 bar within the piping structure.

According to still further features in the described preferred embodiments, the at least one protruding element of each of the first and second wedges is sufficiently embedded in the outer surface of the first and second metal, cylindrical pipe ends such that the pipe coupling arrangement maintains the anchored position for a time period of at least 1 hour, at least 7 days, or at least one year at a fluid pressure of 200 bar within the piping structure.

According to still further features in the described preferred embodiments, the Rockwell C hardness of the at least one protruding element exceeds a Rockwell C hardness of the respective outer surface of the metal, cylindrical pipe end by at least 5, at least 7, at least 10, or at least 15.

According to still further features in the described preferred embodiments, the Rockwell C hardness of the at least one protruding element of the radially-inward wedge surface exceeds a Rockwell C hardness of a respective wedge body of the at least the first wedge element by at least 5, at least 7, at least 10, or at least 15.

According to still further features in the described preferred embodiments, the Rockwell C hardness of the at least one protruding element is at least 40, at least 45, at least 50, at least 55, or at least 60.

According to still further features in the described preferred embodiments, the Rockwell C hardness of the radially-inward surface(s) of the gasket housing element(s) is at most 70, at most 68, or at most 65.

According to still further features in the described preferred embodiments, the sloped, radially-outward surface 73 has a slope or average slope within a range of 5' to 25' with respect radially-inward wedge surface 92, and more typically, within a range of 7' to 22°.

According to still further features in the described preferred embodiments, the at least one protruding element protrudes from the inner wedge element surface (in a radially inward direction) by at least 0.5mm, and more typically, at least lmm, at least 1.5mm, at least 2mm, or at least 3mm According to still further features in the described preferred embodiments, the at least one protruding element protrudes from the inner wedge element surface (in a radially inward direction) by a length within a range of 0.5-6mm, 20 1-6mm, 1-2.5mm, or 1.5-3.0 mm According to still further features in the described preferred embodiments, the at least one protruding element is dimensioned, and is of suitable relative hardness, so as to be embedded within the pipe (in a radially inward direction), after the tightening of the axial closure arrangement into the anchored position, by at least 3mm, at least 4mm, or at least 5mm According to still further features in the described preferred embodiments, the metal cylindrical pipe ends have an external diameter of at least 3mm, or at least 5mm. While the maximal diameter of the pipe ends may not be limited, typically the diameter of the opening is within a range of 3mm to 100cm, 3mm to 80cm, 3mm to 60cm, 5mm to 100cm, 5mm to 80cm, or 5mm to 60cm.

According to yet another aspect of the present invention there is provided a 5 method of affixing pipes in a fixed end-to-end relationship, substantially as disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. Throughout the drawings, like-referenced characters are used to designate like elements.

In the drawings: Figure 1 is a schematic, generally cross-sectional view of the inventive pipe coupling arrangement; Figure 2 provides a schematic, magnified portion of the cross-sectional view shown in Figure 1; Figure 3 is a schematic, partially exploded, perspective view including the inventive pipe coupling arrangement of Figure I; Figure 4 is a schematic, perspective view of an inventive gasket housing element having an integral wedge, as utilized in the inventive pipe coupling arrangement of Figure I; and Figure 5 is another schematic, perspective view of the inventive gasket 5 housing of Figure 4, showing the wedge profile and the protruding elements for anchoring the pipe coupling assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention allows for the facile connection between metal pipes, and obviates the need for initial machine grooving near the ends of the pipes.

The principles and operation of the pipe coupling arrangements and assemblies according to the present invention, and the methods of pipe coupling using such arrangements and assemblies, may be better understood with reference to the drawings and the accompanying description. Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

According to aspects of the present invention, and as collectively shown by way of example in Figures 1-5, there is provided a pipe coupling arrangement 100 holding metal cylindrical pipe ends of a piping structure in fixed end-to-end relationship, the pipe coupling arrangement comprising: (a) a first metal, cylindrical pipe end 12, (b) a second metal, cylindrical pipe end 16; and (c) a pipe coupling assembly 50. In an assembled, operative mode or configuration, pipe coupling assembly 50 includes: (i) a first flange 51 having a first inner flange surface 52 forming a first opening 53 receiving/for receiving first metal, cylindrical pipe end 12; and a second flange 56 having a second inner flange surface 57 forming a second opening 58 receiving/for receiving second metal, cylindrical pipe end 16; (ii) a gasket arrangement 60 disposed (in the assembled mode) between the first and second flanges, the gasket arrangement including at least one gasket 64 and a gasket housing 61, gasket housing 61 including at least one gasket housing element such as gasket housing elements 62, 66. Gasket housing 61 is adapted to radially and axially contain the at least one gasket 64, which is dimensioned to envelop an outer surface 13, 17 of the first and second metal, cylindrical pipe ends 12, 16, and seal therebetween; (iii) at least a first wedge or wedge element 72, 71 disposed (in the assembled mode) axially-outward with respect to gasket housing 61, and contacting and enveloping (or at least partially enveloping) first metal, cylindrical pipe end 12, and a second wedge or wedge element 76 disposed (in the assembled mode) axially-outward with respect to gasket housing 61, and contacting enveloping (or at least partially enveloping) second metal, cylindrical pipe end 16; and (iv) an axial locking arrangement 80 optionally having an axial closure arrangement 81. In the provided embodiment, arrangements 80, 81 have at least one element 82 adapted to pass into or through at least one axial locking and/or closure opening 84, 85 in each of the first and second flanges.

Axial closure arrangement 81 may include a complementary closure assembly typically having complementary threading (not shown) for enabling (e.g., by relative rotation) the axial dosing of a distance between first and second flanges 51, 56 so as to assume the fixed end-to-end relationship. For example, the surface of element 82 may be threaded (e.g., a threaded bolt), with complementary threading being disposed on a nut (not shown), or on an inner surface (not shown) of the axial closure opening in the flange distal to the head 83 of the bolt (element 82).

This fixed end-to-end relationship may be maintained by axial locking arrangement 80. In the complementary threading embodiment, the complementary threading may serve both as an axial closure mechanism that enables axial closure or tightening, and as an axial locking arrangement that maintains the first and second flanges in a fixed end-to-end relationship.

Axial closure may be performed by various external devices. For complementary threading arrangements, a screwing tool or other known rotating mechanisms may be employed. For embodiments in which element 82 is a locking pin, or forms part of a locking pin assembly, various known mechanisms may be employed for axial closure of the flanges (i.e., towards the center of the gasket or gasket housing in an operative mode), including pneumatic, hydraulic, and screwing mechanisms. Once the pipe coupling assembly is brought to a closed state (or "fixed end-to-end relationship"), this closed state may be maintained by the axial locking arrangement (e.g., by the locking pin assembly).

In the complementary threading embodiment described hereinabove with reference to Figure 1, the complementary threading may serve both to enable the axial closure (via the rotation of at least one of the complementary threaded elements) and to axially lock the (relative) position of the first and second flanges.

The axial closure between the first and second flanges that is enabled by the axial closure arrangement may preferably be a solely linear or substantially solely linear closure in which the flanges are linearly drawn together, without rotation of either flange.

In some embodiments, and substantially as best viewed in the perspective view provided by Figure 4, first wedge or wedge element 72 may be attached or integrally attached to a portion of gasket housing 61 (in this exemplary embodiment, to gasket housing element 62), e.g., via at least one axial spacer 75, and second wedge or wedge element 76 may be attached or integrally attached to gasket housing 61 (in this exemplary embodiment, to gasket housing element 66), e.g., via at least one axial spacer 79.

In some embodiments, at least one axial spacer 75 and/or at least one axial spacer 79 may be discrete components, i.e., not integral with the gasket housing and not integral with the wedge or wedge elements.

In some embodiments, at least one axial spacer 75 and/or at least one axial 5 spacer 79 may be discrete components with respect to the gasket housing, but integral with the wedge or wedge elements.

In some embodiments, the first wedge or wedge element and the gasket are axially spaced apart, by a distance D (as shown in Figure I), when the arrangement is disposed in the anchored position. D may be any positive value, e.g., at least lmm, at least 2mm, at least 3mm, at least 4mm or at least 6mm, and typically, within a range of 1-50mm, 2-50mm, 3-50mm, and yet more typically, 3-40mm, 4-30mm or 5-25mm.

In some embodiments, a portion, or all of distance D may be provided by the wall of the gasket housing that axially envelops the gasket.

In some embodiments, a portion, or all of distance D may be provided by the wall of the gasket housing that axially envelops the gasket, along with the axial spacer.

In some embodiments, at least one of the first and second wedges may be a discrete component with respect to the gasket housing.

In some embodiments, the gasket housing may be formed of two or more discrete gasket housing elements, which complement each other in the axial direction. Typically, each of these discrete gasket housing elements is dimensioned to fractionally or partially cover the gasket, in the axial direction.

Figure 5 is another schematic, perspective view of the inventive gasket 25 housing element of Figure 4, showing a wedge profile 91 of first wedge or wedge element 72, a wedge profile 97 of second wedge or wedge element 76. Figure 5 further shows the protruding elements 95, 99, which are disposed, respectively, on the first and second radially-inward wedge surfaces 92, 96 of first and second wedge or wedge elements 72, 76. Protruding elements 95, 99 face and protrude radially inwards, toward the outer surface of the respective pipe ends, and serve to anchor the pipe coupling assembly into the outside surface of the pipe ends, as exemplified in Figure 2 with respect to protruding elements 95.

With specific reference now to Figure 2, Figure 2 provides a schematic, magnified portion of the cross-sectional view shown in Figure 1, in which first wedge or wedge element 72 has assumed an anchored position with respect to first metal, cylindrical pipe end 12, and to outer surface 13 thereof. First wedge or wedge element 72 has: (i) a sloped, radially-outward surface 73 sloping radially outwards towards an axial center C of the gasket housing, and (ii) a radially-inward wedge surface 92 having at least one protruding element 95 protruding radially inwards. First inner flange surface 52 is sloped radially outwards towards axial center C of the gasket housing, and may be complementary or generally complementary to sloped, radially-outward surface 73. Consequently, as axial closure arrangement 80 (shown in Figures I and 3) is tightened or closed, first flange 51 moves in the axial A direction. This axial motion generates solely or substantially solely radially-inward forces, such that first inner flange surface 52 is urged against first wedge or wedge element 72, in the radial (radially inward) It direction.

It is advantageous for the Rockwell C hardness of protruding element 95 to exceed the Rockwell C hardness of a respective outer surface 13 of the metal, cylindrical pipe end, which facilitates the embedment of protruding element 95 25 into outer surface 13, to achieve an anchored position.

Typically, the Rockwell C hardness of the at least one protruding element exceeds the Rockwell C hardness of the respective outer surface of the metal, cylindrical pipe end by at least 5, at least 7, at least 10, or at least 15 (A Rockwell C).

In some embodiments, the Rockwell C hardness of the wedge or wedge element, or of the at least one protruding element thereof, is at least 40, at least 42, at least 45, at least 47, or at least 50.

In some embodiments, the Rockwell C hardness of the wedge or wedge 5 element, or of the at least one protruding element thereof, is at most 70, at most 68, or at most 65.

In some embodiments, the Rockwell C hardness of the metal, cylindrical pipe end, and/or the outer surface thereof, is at least 10 Rockwell C, at least 20 Rockwell C, or at least 25 Rockwell C. Typically, the hardness of the metal, cylindrical pipe end, and/or the outer surface thereof, is within a range of 10-30 Rockwell C. In some embodiments, the Rockwell C hardness of the at least one protruding element of the inner wedge element surface exceeds a Rockwell C hardness of a respective wedge or wedge element body by at least 5, at least 7, at least 10, or at least 20 (Rockwell C). This may be achieved by selective surface hardening of the inner wedge surface of the wedge or wedge elements.

In some embodiments, the at least one protruding element of the wedge or wedge elements is, or includes, one or more ridges.

In some embodiments, the at least one protruding element (or the contact area between the at least one protruding element and the outer surface of the pipe) encompasses at least 20%, at least 40%, at least 50%, at least 60%, and more typically, at least 80%, at least 90% (and in the case of a spiral protrusion or other arrangements imparting radial flexibility), at least 100%, at least 120%, at least 140%, at least 170%, at least 200%, or at least 250% of an outer circumference of the respective pipe end of the metal, cylindrical pipe ends. The at least one protruding element may be a continuous ridge and/or a series of individual protrusions.

In some embodiments, the at least one protruding element protrudes from the inner wedge element surface (in a radially inward direction) by at least 0.5mm, and more typically, at least lmm, at least 1 5mm, at least 2mm, or at least 3mm.

In some embodiments, the at least one protruding element protrudes from the inner wedge element surface (in a radially inward direction) by a length within a range of 0.5-6mm, 1-6mm, 1-2.5mm, or 1.5-3.0 mm In some embodiments, the at least one protruding element is dimensioned, and is of suitable relative hardness, so as to be embedded within the pipe (in a 10 radially inward direction), after the tightening of the axial closure arrangement into the anchored position, by at least 3mm, at least 4mm, or at least 5mm It must be emphasized that the above-described anchoring mechanism may essentially obviate the need for disposing protruding elements in the radially-inward surface(s) (e.g., radially-inward surface 65) of the gasket housing element(s). Consequently, these surfaces are typically devoid of protruding elements.

Alternatively or additionally, these surfaces need not have a high Rockwell C hardness. Typically, the A Rockwell C of the radially-inward surface(s) of the gasket housing element(s) with respect to the respective outer surface of the 20 metal, cylindrical pipe end is at most 5, at most 3, at most 1, or at most O. In some embodiments, the sloped, radially-outward surface 73 has a slope or average slope within a range of 5° to 25° with respect radially-inward wedge surface 92, and more typically, within a range of 7° to 22°.

In some embodiments, and most typically, the first flange and/or the second flange are axially spaced apart with respect to the at least one gasket housing, in in the anchored position, so as to leave an axial space 19.

In some embodiments, the sum of the arcs of all the first 72, 71 wedge elements is less than 360°, and more typically, at most 355°, at most 350°, at most 345° or at most 340°, so as to impart radial flexibility to the wedge elements.

The sum of the arcs of all the first wedge elements may actually exceed 360°, as long as the wedge elements exhibit sufficient radial flexibility (e.g., in a spiral configuration). Thus, in some embodiments, the sum of the arcs of all the first 72, 71, wedge elements is at least 360°, at least 450°, at least 540°, at least 630°, at least 720°, or at least 8 I 0°.

The inventive pipe coupling arrangement, or the inventive pipe coupling assembly (e.g., in operative, assembled mode or configuration) may fulfill at least one, at least two, at least three, at least four, and most typically, all five of the following structural conditions: #1. in the tightening mode, the at least first wedge or wedge element and/or the at least second wedge or wedge element are axially fixed, respectively, with reference to the first and second metal, cylindrical pipe end; #2. in the tightening mode, the at least first wedge or wedge element (and typically the at least second wedge or wedge element as well) are axially fixed with respect to the gasket housing; #3. in the tightening mode, an internal axial movement or motion (i.e., axially inward motion, towards the axial center of the coupling or gasket) of the first flange is converted into substantially solely radial motion (i.e., radially inward motion, towards the radial center of the pipe when the pipe is in place) of the first wedge or wedge element, and the same may hold true for the second flange with respect to the second wedge or wedge element; #4. in the anchored position, the first flange (and typically the second flange) is axially spaced apart with respect to the at least one gasket housing; #5. in the anchored position, the first wedge or wedge element and the gasket (and typically the second wedge or wedge element and the gasket as well) are axially spaced apart.

In some embodiments, the inventive pipe coupling arrangement or assembly may fulfill at least both the structural conditions #1 and #5.

In some embodiments, the inventive pipe coupling arrangement or assembly may fulfill at least both the structural conditions #2 and #5.

In some embodiments, the inventive pipe coupling arrangement or assembly may fulfill at least both the structural conditions #3 and #5.

In some embodiments, the inventive pipe coupling arrangement or assembly may fulfill at least both the structural conditions #4 and #5.

In some embodiments, the inventive pipe coupling arrangement or assembly may fulfill at least the structural conditions #1, #3 and #5.

In some embodiments, the inventive pipe coupling arrangement or assembly may fulfill at least the structural conditions #2, #3 and #5.

In some embodiments, the inventive pipe coupling arrangement or assembly may fulfill at least the structural conditions #3, #4 and #5.

While Figure 2 shows only a portion of the first side of the inventive pipe coupling arrangement, it will be appreciated that the second side may be identical or substantially identical (e.g., a mirror image of the first side).

Figure 3 is a schematic, partially exploded, perspective view including the inventive pipe coupling arrangement and assembly of Figure 1. In this exemplary embodiment, gasket housing 61 includes gasket housing elements 62, 66, which together radially (3600) and axially encompass gasket 64 on both sides.

In some embodiments, gasket housing elements 62, 66 may be fixed and attached together by a closure assembly such as a tangential closure assembly 67. Closure assembly 67 may include at least one element (and typically two elements) such as a bolt 63 adapted to pass into or through at least one closure 5 opening 68, 69 disposed in each of gasket housing elements 62, 66, closure assembly 67 typically including a complementary closure assembly (e.g., having complementary threading, not shown) for fixing together gasket housing elements 62, 66 around gasket 64. For example, the surface of element 63 may be threaded (e.g., a threaded bolt), with complementary threading being disposed 10 on a nut (not shown), or on an inner surface (not shown) of the closure opening in the gasket housing element distal to the head of element 63.

It will be appreciated that pipe coupling assembly 50 may be adapted to accommodate first pipe end 12 and second pipe end 16, where the diameter of second pipe end 16 is different from the diameter of first pipe end 12.

While as shown, the wedge element may be integrally attached to the gasket housing by at least one axial spacer, in some embodiments, the wedge element may be a distinct component or element to the gasket housing.

In some embodiments, the axial spacing may be achieved by means of an axial spacer element that is distinct from both the wedge element and the gasket 20 housing.

In some embodiments, the axial spacing may be achieved by means of an axial spacer that is integral with the wedge element but distinct from the gasket housing.

In some embodiments, the axial spacing may be achieved by means of an 25 axial spacer that is integral with the gasket housing but distinct from the wedge element.

In some embodiments, the axial spacer has an axial length of at least I mm or at least 2mm, and may typically be in the range of 1-3mm In some embodiments, the axial spacing has an axial length of at least I mm or at least 2mm, and may typically be in the range of 1-3mm In some embodiments, the opening formed by the inner surface of the first and/or second inner flange surface has a diameter of at least 3mm, or at least 5mm. While the maximal diameter of this opening may not be limited, typically the diameter of the opening is within a range of 3mm to I 00cm, 3mm to 80cm, 3mm to 60cm, 5mm to 100cm, 5mm to 80cm, or 5mm to 60cm.

In some embodiments, the gasket is of the self-sealing gasket variety, i.e., pressure buildup within the pipe presses the gasket walls against the pipe surface, producing or augmenting the sealing effect.

In some embodiments, the gasket is adapted such that the sealing is effected or solely effected by a super-atmospheric pressure of a fluid disposed within the arrangement or assembly, e.g., between the cylindrical pipe ends.

In some embodiments, the gasket is adapted such a super-atmospheric pressure (e.g., at least 10 bar, at least 15 bar, at least 20 bar, or at least 25 bar) of a Iluid disposed within the arrangement or assembly (e.g., between the cylindrical pipe ends) acts on the gasket to contact, and be urged against, the outer surface of at least one of the cylindrical pipe ends, so as to effect the sealing.

In some embodiments, at least one of the pipe ends is devoid or functionally or substantially devoid of grooving or circumferential grooving in the outer wall or surface thereof.

In some embodiments, and most typically, both of the pipe ends are devoid of grooving or circumferential grooving in the outer wall or surface thereof.

In some embodiments, the pipe coupling assembly is disposed on an ungrooved portion of at least one (and typically both) of the pipe ends.

The pipe coupling arrangement of the present invention may allow for the easy, quick and low-cost coupling of pipework, more specifically, metal pipework, and yet more specifically, metal pipework designed to operate at high pressures of at least 10 bar or at least 15 bar, and more typically, at least 20 bar, at least 25 bar, at least 30 bar, at least 40 bar, at least 50 bar, at least 60 bar, at least 80 bar, at least 100 bar, at least 120 bar, at least 150 bar, at least 200 bar, or at least 250 bar.

Typically, the pipe coupling arrangement of the present invention is suitable for operation within a pressure or nominal pressure range of 10 to 300 bar, 10 to 250 bar, 10 to 200 bar, 15 to 300 bar, 15 to 250 bar, 15 to 200 bar, 20 to 300 bar, 20 to 250 bar, 20 to 200 bar, 25 to 250 bar, 25 to 200 bar, 30 to 250 bar, 30 to 200 bar, 40 to 250 bar, 40 to 200 bar, 50 to 300 bar, 50 to 250 bar, 50 to 200 bar, 60 to 300 bar, 60 to 250 bar, 60 to 200 bar, 70 to 300 bar, 70 to 250 bar, 70 to 200 bar, 80 to 300 bar, 80 to 250 bar, 80 to 200 bar, 90 to 300 bar, 90 to 250 bar, 90 to 200 bar, 100 to 300 bar, 100 to 250 bar, 100 to 200 bar, 120 to 300 bar, 120 to 250 bar, 150 to 300 bar, 150 to 250 bar, or 200 to 300 bar.

The pipe coupling arrangement of the present invention enables reliable 20 direct pipe connection and may completely obviate the need for preliminary grooving of the respective pipe ends, even under the piping pressures or pressure ranges provided hereinabove.

The inventors have found various ways of attaining superior performance at pressures near the higher end of the above-provided pressure ranges.

It is important that the selected components and materials of construction are appropriate for the operating conditions, most notably pressure, but temperature, pH, etc., as well. For example, care should be taken to select gaskets and gasket materials that are suitable for these elevated operating pressures.

For higher pressures, the protruding elements should typically have Rockwell C high hardness (absolute). as well as a large A Rockwell C with 5 respect to the pipe ends. Longer protruding elements may also be more appropriate for such higher pressures.

The radially-inward force delivered by the inner flange surface should be exerted over the entire circumference (i.e., as close as practically possible) of the sloped outer surface of the wedge.

Similarly, the number of rings or spirals of protruding elements may be increased for stronger anchoring of the wedge.

The tightening forces should be suitably strong, such that the components responsible for generating and maintaining the tightening forces should be robustly designed, accordingly.

As used herein in the specification and in the claims section that follows, the term "bar", with respect to pressure, refers to bar gauge.

As used herein in the specification and in the claims section that follows, the term "fixed end-to-end relationship" with respect to a pipe coupling arrangement holding and/or anchoring and/or sealing of metal cylindrical pipe ends of a piping structure, is specifically meant to include elbow arrangements, arrangements, tee reducing coupling arrangements, and valve arrangements such as ball-valve arrangements. Those of skill in the art will readily appreciate that other known pipe coupling arrangements exist that would also fall under the definition of "fixed end-to-end relationship".

As used herein in the specification and in the claims section that follows, a component or a surface thereof having a hardness below 0 (zero) on the Rockwell C scale, is assigned a Rockwell C hardness of 0 (zero).

As used herein in the specification and in the claims section that follows, the term "internal" with respect to an axial vector, e.g., "internal axial motion", refers to a direction towards the axial center of the gasket housing.

As used herein in the specification and in the claims section that follows, the term "substantially" with respect to the term "solely radial motion-, e.g., with respect to a wedge, is meant to exclude parasitic motions in the non-radial direction. Thus, a generally radial motion having such a parasitic non-radial vector or component would fall within the limitation "substantially solely radial motion".

As used herein in the specification and in the claims section that follows, the term "substantially" with respect to the term "solely linear", is meant to exclude parasitic motions in the non-linear direction. Thus, a generally linear movement having such a parasitic non-linear vector or component would fall within the limitation "substantially solely linear-and the like. The term "solely linear" is meant to exclude linear closure achieved by rotation (e.g., the linear advancement of a flange by screwing/rotation).

As used herein in the specification and in the claims section that follows, the term "at least one of A and B" and the like is equivalent to an inclusive "or", and includes any one of "only A", "only B", or "A and B". Similarly, the term "at least one of A, B, and C" and the like is equivalent to an inclusive "or", and includes any one of "only A", "only B", "only C", "A and B", "A and C", "B and C", or "A and B and C".

As used herein in the specification and in the claims section that follows, the terms "top", "bottom", "upper", "lower", "height" and "side" and the like are utilized for convenience of description or for relative orientation, and are not necessarily intended to indicate an absolute orientation in space.

As used herein in the specification and in the claims section that follows, the term "substantially" is to be understood as understood by those of skill in the art, unless defined otherwise.

It will be appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

Claims

WHAT IS CLAIMED IS: 1. A pipe coupling arrangement holding metal cylindrical pipe ends of a piping structure in a fixed end-to-end relationship, the pipe coupling arrangement comprising, in an assembled, operative mode: (a) a first metal, cylindrical pipe end; (b) a second metal, cylindrical pipe end; and (c) a pipe coupling assembly including: (i) first and second flanges, said first flange having a first inner flange surface forming a first opening receiving said first metal, cylindrical pipe end; said second flange having a second inner flange surface forming a second opening receiving said second metal, cylindrical pipe end; (ii) a gasket arrangement disposed between said first and second flanges, said gasket arrangement including at least one gasket radially enveloping an outer surface of said first and second metal, cylindrical pipe ends, and sealing therebetween; and a gasket housing including at least one gasket housing element, said gasket housing radially and axially containing said at least one gasket; (iii) at least a first wedge disposed around said first metal, cylindrical pipe end; and at least a second wedge disposed around said second metal, cylindrical pipe end; and (iv) an axial closure arrangement having at least one threaded element passing through at least one opening in each of said first and second flanges, said axial closure arrangement including threading complementary to said at least one threaded element for axially closing a distance between said first and second flanges; wherein said at least said first wedge and said at least. said second wedge each have: (i) a sloped, radially-outward surface sloping radially outwards towards an axial center of said gasket housing, and (i1) a radially-inward wedge surface having at least one protruding element protruding radially inwards; wherein a hardness of said at least one protruding element exceeds a hardness of a respective outer surface of said metal, cylindrical pipe end; and wherein each of said first and second inner flange surfaces is sloped radially outwards towards said axial center of said gasket housing; whereby, as said axial closure arrangement is closed in a tightening mode, each of said first and second inner flange surfaces envelops said respective sloped outer surface and delivers a radially-inward force thereto, such that said at least one protruding element of each of said first and second wedge elements is embedded in said outer surface of said first and second metal, cylindrical pipe ends, to achieve an anchored position.
2. The pipe coupling arrangement of claim I, wherein, in said tightening mode, each of said at least a first wedge and said at least a second wedge are axially fixed, respectively, with reference to said first and second metal, cylindrical pipe ends.
3. The pipe coupling arrangement of claim 1 or claim 2, wherein, in said tightening mode, said at least first wedge is axially fixed with respect to said gasket housing.
4. The pipe coupling arrangement of any one of claims 1 to 3, wherein, in said tightening mode, an internal axial motion of said first flange is converted into substantially solely radial motion of said first wedge.
5. The pipe coupling arrangement of any one of claims 1 to 4, wherein, in said anchored position, said first flange and said at least one gasket housing are axially spaced apart.
6. The pipe coupling arrangement of any one of claims 1 to 5, wherein, in said anchored position, said first wedge element and said gasket are axially spaced apart.
7. The pipe coupling arrangement of any one of claims 1 to 6, wherein said radially-inward force delivered by said first and second inner flange surfaces is exerted over at least 80% of a circumference of said sloped outer surface.
8. The pipe coupling arrangement of claim 7, wherein said radially-inward force delivered by said first and second inner flange surfaces is exerted over at least 95% of said circumference of said sloped outer surface.
9. The pipe coupling arrangement of any one of claims 1 to 8, wherein a span of said at least one protruding element encompasses at least 50% of an outer circumference of a respective pipe end of said first and second metal, cylindrical pipe ends.
10. The pipe coupling arrangement of claim 9, wherein said span of said at least one protruding element encompasses at least 80% of said outer circumference.
11. The pipe coupling arrangement of claim 9. wherein said span of said at least one protruding element encompasses at least 120% of said outer circumference.
12. The pipe coupling arrangement of claim 9, wherein said span of said at least one protruding element encompasses at least 150% of said outer circumference.
13. The pipe coupling arrangement of any one of claims 1 to 12, wherein said pipe coupling assembly is disposed on an ungrooved portion of said first metal, cylindrical pipe end.
14. The pipe coupling arrangement of any one of claims 1 to 13, wherein said first metal, cylindrical pipe end is unrooved.
15. The pipe coupling arrangement of any one of claims 1 to 14, wherein said axial closure arrangement is adapted to close said distance between said first and second flanges in a solely linear or substantially solely linear fashion.
16. The pipe coupling arrangement of any one of claims 1 to 15, wherein said at least one protruding element of each of said first and second wedges is sufficiently embedded in said outer surface of said first and second metal, cylindrical pipe ends such that the pipe coupling arrangement maintains said anchored position for a time period of at least 1 hour at a fluid pressure of 100 bar within the piping structure.
17. The pipe coupling arrangement of any one of claims 1 to 15, wherein said at least one protruding element of each of said first and second wedges is sufficiently embedded in said outer surface of said first and second metal, cylindrical pipe ends such that the pipe coupling arrangement maintains said anchored position for a time period of at least 1 hour at a fluid pressure of 200 bar within the piping structure.
18. The pipe coupling arrangement of claim 17, wherein said time period is at least 7 days.
19. The pipe coupling arrangement of any one of claims 1 to 18, wherein a Rockwell C hardness of said at least one protruding element exceeds a Rockwell C hardness of said respective outer surface of said metal, cylindrical pipe end by at least 5, at least 7, at least 10, or at leas( 15.
20. The pipe coupling arrangement of any one of claims 1 to 19, wherein a Rockwell C hardness of said at least one protruding element of said radially-inward wedge surface exceeds a Rockwell C hardness of a respective wedge body of said at least said first wedge element by at least 5, at least 7, at least 10, or at least 15.