WO2002014719A1 - A seal and a pipe system allowing for misalignment - Google Patents
A seal and a pipe system allowing for misalignment Download PDFInfo
- Publication number
- WO2002014719A1 WO2002014719A1 PCT/AU2001/001014 AU0101014W WO0214719A1 WO 2002014719 A1 WO2002014719 A1 WO 2002014719A1 AU 0101014 W AU0101014 W AU 0101014W WO 0214719 A1 WO0214719 A1 WO 0214719A1
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- WO
- WIPO (PCT)
- Prior art keywords
- pipe
- seal
- male
- female
- sealing
- Prior art date
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L21/00—Joints with sleeve or socket
- F16L21/02—Joints with sleeve or socket with elastic sealing rings between pipe and sleeve or between pipe and socket, e.g. with rolling or other prefabricated profiled rings
- F16L21/035—Joints with sleeve or socket with elastic sealing rings between pipe and sleeve or between pipe and socket, e.g. with rolling or other prefabricated profiled rings placed around the spigot end before connection
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/02—Sealings between relatively-stationary surfaces
- F16J15/021—Sealings between relatively-stationary surfaces with elastic packing
- F16J15/022—Sealings between relatively-stationary surfaces with elastic packing characterised by structure or material
- F16J15/024—Sealings between relatively-stationary surfaces with elastic packing characterised by structure or material the packing being locally weakened in order to increase elasticity
- F16J15/025—Sealings between relatively-stationary surfaces with elastic packing characterised by structure or material the packing being locally weakened in order to increase elasticity and with at least one flexible lip
Definitions
- TITLE A SEAL AND A PIPE SYSTEM ALLOWING FOR MISALIGNMENT
- the present invention relates to seals of the type used to seal adjacent or adjoining components in an assembly.
- seals it is known to use seals to facilitate the connection of adjoining components in situations where pressure differentials would otherwise produce leakage. They are also used in applications where it is important to avoid intermixing of different fluids across an interface between adjoining components in a system. A particularly important application is in pipelines and piping systems, where known seals are prone to a number of inherent disadvantages.
- Pipelines and pipe networks are usually formed by interconnecting a multitude of discrete pipe sections.
- the pipe sections must be securely joined to prevent failure.
- the joins must also be effectively sealed to avoid leakage and excessive loss of fluid pressure along the pipe.
- the sections to be connected are usually configured so that the outer diameter of each male end is marginally smaller than the inner diameter of the corresponding female end of the adjoining section.
- Such configurations may be achieved by using pipe sections of different size, by forming a circumferential rebate around the outer wall of one pipe section to form a male end, by flaring or pre-belling the wall of one pipe section to form a female end, by fitting an external collar around the abutting pipe ends so as to overlap the join, or by some combination of these techniques.
- One common form of pipe seal is the O-ring.
- This type of seal comprises an annular ring, normally of circular cross-sectional profile, formed from an elastomeric material such as rubber. It is typically retained within a circumferential groove formed around one end of a pipe section, normally the male end.
- the O-ring is sized to protrude radially beyond the upper marginal edges of the retaining groove, above the surrounding surface of the pipe end, so that upon insertion into a corresponding female end of an adjoining pipe section, the O-ring is resiliently compressed.
- a circumferential groove is also formed around the inner periphery of the female pipe end to facilitate captive retention of the O-ring and to resist withdrawal of the adjoining pipe sections, following installation.
- O-rings of this type have been found to function satisfactorily in relatively small scale and low pressure applications. However, they are problematic in the context of larger scale pipelines such as water and sewage mains, because of the relatively high levels of axial force required in order to compress the seal during engagement of the adjoining pipe ends. It has also proven to be difficult in practice to locate O-ring seals securely during installation, because of the tendency for these seals to roll along the surrounding surfaces in response to relative axial displacement of the pipe ends during the installation procedure. A further deficiency is that conventional O-ring seals have been found to provide inadequate sealing performance in high pressure applications.
- V-shaped pressure seals In an attempt to address some of these inherent limitations in conventional O-ring seals, V-shaped pressure seals, or V-seals, have been developed. These seals are also generally annular or ring shaped. However, the cross-sectional profile is typically V or U-shaped, being defined in profile by a pair of diverging "arms". In use, the seal is positioned such that one arm of the V diverges radially inwardly for sealing engagement with the outer circumference of the male pipe end, while the other arm diverges radially outwardly for sealing engagement with the inner circumference of the adjoining female pipe end. In this configuration, radial compression of the seal involves movement of the arms toward one another and advantageously, this requires considerably less axial installation force than a comparable O-ring seal.
- V-seals also have the advantage that, with the valley of the V oriented toward the high pressure side of the junction, the pressure differential across the seal tends to expand the arms of the V outwardly so as to enhance the effectiveness of the seal. In this way, the greater the pressure differential between the interior and the exterior of the pipe under normal operating conditions, the more effective the seal becomes. This feature of pressure responsiveness provides a further improvement over O-ring seals.
- seals of this type are different depending upon whether the pressure within the pipe is higher than the surrounding pressure or vice versa.
- the seals are also shaped differently according to whether they are to be used in conjunction with rebated, flared, or collared pipe ends.
- the proliferation in seals due to these variations spread across a large array of pipe thicknesses and diameters creates production inefficiencies, complicates inventory control, and ultimately leads to increased costs. It also gives rise to a significant potential for operator error during installation because of the possibility of the wrong type of seal being specified or used, or the correct seal being installed in an incorrect orientation.
- V-seals are not ideally suited to applications where the relative pressure between the interior and the exterior of the pipe fluctuates between positive and negative values. This is because the seals, being pressure responsive, are directionally biased and if optimised for one situation, they will be compromised in the other. Accordingly, if pressure across the interface is likely to be intermittently reversed, multiple seals in opposing orientations are required which further adds to the cost and complexity of the installation procedure. In practice, V-seals are also prone to fouling and moving out of position during the installation process.
- the invention provides a pressure seal for sealing first and second components in an assembly, said seal including a base, a first sealing portion, a second sealing portion spaced apart from the first, and connection means interactively connecting the first and second sealing portions, the base being adapted sealingly for location on the first component, whereby engagement with the second component compresses the first portion to form a first fluid seal, and said compression operates through the connection means to urge the second portion into engagement with the second component to form a second fluid seal between the first and second components.
- the seal is generally annular in shape and is preferably adapted to seal a connection between a male end of a first pipe section and a complementary female end of a second pipe section adjoining the first.
- the seal is preferably adapted to facilitate the assembly of a plurality of discrete pipe sections in series to form a pipeline.
- the first portion of the seal includes a first sealing rim and the second portion includes a second sealing rim displaced axially and radially from the first.
- the connection means preferably include a bridge section extending between the first and second sealing rims.
- the connection means preferably also include a resilient connection accommodating a limited degree of pivotal or rocking movement between the bridge section and the base.
- the base portion of the seal is adapted to be captively and sealingly retained within a channel or groove extending circumferentially around an outer surface of the male end of the first pipe section. More preferably, the base of the groove is inclined toward the proximal end of the first pipe section, to resist axial displacement or dislocation upon insertion into the female end of the adjoining pipe section.
- the rims are positioned such that with the seal supported on the male end of the first pipe section, and upon axial engagement with the second pipe section, the female pipe end initially passes over the second sealing rim to engage the first rim.
- the first portion of the seal including the first rim preferably begins to compress.
- the bridge section preferably rotates or rocks relative to the base, whereby the second sealing rim is urged radially outwardly into sealing engagement with the interior surface of the female pipe end.
- the seal includes a first outwardly diverging generally V-shaped notch extending circumferentially between the first sealing portion and the base.
- a second outwardly diverging generally V-shaped notch preferably extends circumferentially on the opposite side of the seal between the second sealing portion and the base.
- the first and second notches preferably converge toward one another, to define a neck region in the seal.
- the neck region is preferably adapted to facilitate the pivotal or rocking movement between the bridge section and the base, during which the first notch closes while the second notch opens, or vice versa.
- the cross-sectional profile of the seal as defined by the base, the first and second sealing rims and the intermediate V-notches is generally K-shaped.
- each of the V- notches is advantageously adapted to perform a pressure responsive function, whereby an increase in pressure on either side of the seal urges the respective rim and the associated side of the base apart with respect to one another and into enhanced sealing engagement with the adjacent pipe walls.
- the seal is pressure responsive on both sides.
- the seal is formed as a unitary component, from a suitable elastomeric material such as rubber, polyurethane, polyethylene, nylon, Nitrile, silicone or the like. It will be appreciated, however, that in alternative embodiments, the seal may be formed in multiple components, from multiple materials, or from similar materials of different stiffiiess, density, resiliency, flexibility or the like. It may also be internally reinforced or externally braced if required.
- connection means may additionally or alternatively include a fluid or a gel adapted to pass between the first and second portions of the seal or other means to provide the desired interaction.
- the invention provides a pipe system including a first pipe section having a male end and a second pipe section having a complementary female end, the male and female ends being adapted for connection in overlapping relationship to join the pipe sections together, the male end or the female end incorporating a first circumferential recessed channel disposed to permit a limited extent of relative radial displacement of the female end in response to axial misalignment between the pipe sections, thereby to accommodate a limited degree of relative rotational displacement about an axis normal to the axes of the adjoining pipe sections.
- the channel in the male pipe end or spigot effectively translates the female corner nip point, up to the limit of relative rotational displacement about the normal axis between the adjoining pipe sections.
- the male or female pipe end incorporates a second circurnferential recess, groove or channel spaced apart from the first channel and adapted in use to locate a pipe seal in an overlapping region between the male and female pipe ends.
- the first channel is recessed into the male pipe end.
- the second channel is also recessed into the male pipe end, forwardly of the first channel.
- the system is adapted for use with a double-rimmed pressure seal, as previously defined. This type of seal is particularly advantageous in the present context, because the neck region, between the base and the bridge section, readily deforms to accommodate the relative rotational displacement between the adjoining pipe sections, without compromising the performance or efficiency of the seal in any way.
- the male end also incorporates a circumferential land between the first and second channels, defining a zone of minimal radial clearance between the male and female pipe ends.
- the circumferential land thereby tends to define the point or region of relative rotation between the adjoining pipe sections about the normal axis.
- a nose section of the male pipe end disposed forwardly of the second channel and the seal has a diameter less than that of the circumferential land, so as to permit an additional degree of said relative rotational displacement generally about the land surface before the outer peripheral rim section abuts the adjacent inner peripheral surface of the surrounding female pipe end.
- the nose section preferably incorporates a tapered, frusto-conical outer surface oriented so as to facilitate surface-to-surface contact between the male pipe end and the adjacent inner surface of the female pipe end, thereby avoiding a relatively sharp spigot corner nip point, at the limit of relative rotational displacement.
- the pipe sections are formed from fibre reinforced cement (FRC), and the male and female end formations, including the various grooves, channels and lands as defined, are moulded or machined into the corresponding outer and inner surfaces on the respective ends of these sections.
- FRC fibre reinforced cement
- a plurality of straight pipe sections manufactured in accordance with this aspect of the invention maybe joined end to end in series to form a curved pipeline, or a gently radiused corner in an existing pipeline, without the need for separately manufactured curved pipe sections, elbow junctions, or the like.
- Figure 1 is a front elevational view showing a seal according to a first aspect of the present invention
- Figure 2 is a side elevation showing the seal of Figure 1;
- Figure 3 is a cross-sectional view taken along line HI-HI of Figure 1;
- Figure 4 is an enlarged cross-sectional view of the seal taken from Figure 3;
- Figure 5 is a cross-sectional view showing the seal of Figures 1 to 4 in position on the male end of a first pipe section, ready for engagement with the female end of an adjoining pipe section;
- Figure 6 is a cross-sectional view similar to Figure 5, showing the adjoining pipe sections fully engaged with the seal in the operative position;
- Figures 7 to 19 are a series of cross-sectional views similar to figure 4, showing a variety of alternative embodiments of the invention, designed for different pipe sizes, pressures, materials, situations and applications;
- Figure 20 is a side elevation showing a pipe section according to a second aspect of the invention.
- Figure 21 is an enlarged side elevation showing the spigot formed on the male end of the pipe section of figure 20;
- Figure 22 is a cross-sectional view of the pipe section of figure 20;
- Figure 23 is an enlarged cross-sectional view of the spigot on the male end of the pipe section
- Figure 24 is an enlarged cross-sectional view of the socket on the female end of pipe section
- Figure 25 is an enlarged cross-sectional view showing the inter-engagement of the spigot of the first pipe section with the socket on the female end of a second like pipe section at the inner radius of a bend, in response to relative rotation between the two pipe sections;
- Figure 26 is an enlarged cross-sectional view similar to figure 25, but showing the interaction between the adjoining pipe sections at the outer radius.
- the invention provides an annular pressure seal 1 for joining and sealing first and second pipe sections in a pipeline.
- the seal includes a base 2, a first sealing portion 3, and a second sealing portion 4 (as best seen in Figure 4).
- the first portion includes a first sealing rim 5, while the second portion includes a second sealing rim 6 displaced axially and radially from the first with the seal in the relaxed configuration.
- the first and second sealing portions are interconnected by means of abridge section 10.
- the seal further includes a first outwardly diverging V-shaped notch 12 extending circumferentially between the first sealing portion 3 and the base.
- a second outwardly diverging V-shaped notch 13 extends circumferentially on the opposite side of the seal, between the second sealing portion 4 and the base.
- the first and second notches 12 and 13 converge toward one another, to define an intermediate neck 14 in the seal.
- This neck is adapted resiliently to accommodate a limited degree of pivotal or rocking movement in either direction between the bridge section 10 and the base, during which the first notch 12 progressively closes while the second notch opens, or vice versa.
- the cross-sectional profile of the seal as thus defined by the base, the first and second sealing portions, the intermediate V-notches and the neck is generally K-shaped.
- the seal is ideally formed as a single, unitary component from a suitable elastomeric material such as rubber, polyurethane, nylon, silicone or the like. It will be appreciated, however, that in alternative embodiments, the seal may be formed from multiple components, from multiple materials, or from similar materials of different stiffness, density, resiliency, flexibility or other material characteristics. It may also be internally reinforced or externally braced if required.
- Figures 5 and 6 show the use of the seal to form a fluid tight connection between a male end 15 of a first pipe section 16 and the complementary female end 17 of a second pipe section 18, as part of a pipeline assembly.
- the male end 15 of the first pipe section is defined by means of an annular external rebate 19 formed in the outer side wall of one end of that pipe section.
- the female end 17 is defined by means of an annular internal rebate 20 formed in the inner side wall of the adjoining pipe section 18.
- the outer diameter of the male pipe end 15 is marginally less than the inner diameter of the corresponding female pipe end 17, to allow for a limited degree of overlapping interengagement.
- This system is particularly well suited for use with pipes formed from fibre reinforced cement (FRC), which typically have relatively thick side walls.
- FRC fibre reinforced cement
- the base portion 2 of the seal is then captively and sealingly retained within a groove 25 extending circumferentially around the outer surface of the male pipe end 15.
- the groove is advantageously inclined toward the end of the section, ⁇ so as to resist axial displacement, dislocation or rolling of the seal out of position upon engagement with the female end of the adjoining pipe sect on.
- the asymmetry of both the seal and the groove also helps to prevent inadvertent installation of the seal in the incorrect orientation.
- preferred angle of inclination is between 5° and 30°, and is ideally around 10° to the horizontal (i.e. with respect to the axis of the pipe section).
- the pipe sections are positioned ready for engagement, as shown in Figure 5.
- the female pipe end initially passes over the second rim 6, to engage the first rim 5. This occurs because in the relaxed condition the first rim 5 protrudes radially outwardly beyond the second rim.
- the first portion 3 of the seal, including the first rim 5 begins to compress radially inwardly.
- the bridge section 10 rotates about the neck 14 relative to the base.
- the second sealing rim 6 is urged radially outwardly into sealing engagement with the interior surface of the female pipe end.
- the base of the seal is retained securely in position within the inclined groove 25 in the male pipe end.
- Figure 6 the configuration of the seal with the pipe ends fully engaged is shown in Figure 6.
- the first rim forms a first seal
- the second rim forms a second seal with the internal surface of the female pipe end.
- the first rim, the second rim and the intermediate bridge section lie in substantially the same plane, such that the bridge portion also performs a sealing function.
- the inner edge of the retaining groove 25 incorporates an inclined shoulder 30, corresponding to an inclined face 31 formed in the first portion of the seal.
- this shoulder abuttingly supports the face 31 on the seal, to ensure adequate sealing pressure is maintained at the first rim.
- the base seals against the inner surface of the retaining groove. In this configuration, with the seal in a state of resilient compression, a secure fluid tight connection is formed between the adjoining pipe sections.
- the first and second V-notches 12 and 13 are advantageously adapted to perform a pressure responsive function.
- an increase in relative pressure on either side of the seal urges the respective rim and the corresponding side of the base more forcefully into engagement with the surrounding pipe walls, thereby to enhance the effectiveness of the seal.
- the seal is pressure responsive in both directions and so its performance is not compromised irrespective of whether the pressure within the pipe is positive or negative relative to the surrounding atmosphere.
- Figures 7 to 19 are a series of cross-sectional views, showing seals in a similar orientation to that shown in figure 4, according to a number of alternative embodiments of the invention. Corresponding features are denoted by equivalent reference numerals, and so these alternative embodiments are not described individually in great detail. Nevertheless, certain salient features should be noted.
- the inner face of the base 2 incorporates an axial array of circumferentially extending ribs 35, and interstitial grooves 36. These ribs are disposed for engagement with the mating outer surface of the circumferential retaining groove or recess 25, which extends around the outer periphery of the associated male pipe end.
- the localised pressure concentrations in the vicinity of the ribs provide improved sealing performance between the base of the seal and the retaining groove. This feature has been found to be particularly significant in preventing slow leakage under low-pressure conditions, when the pressure-responsive sealing enhancement provided by the V-notches is at a sub- optimal level.
- Similar ribbing formations may additionally or alternatively be provided on one or more of the outer surfaces of the seal if required, to enhance sealing and resist leakage between the sealing rims and the mating inner peripheral surface of the surrounding female pipe end, again particularly under low-pressure conditions.
- the first sealing portion 3 and or the associated rim are relatively thicker than in the seal illustrated, for example, in figure 4. This minimises the risk of the lip inadvertently folding back over itself either during the installation procedure, or subsequently under adverse pressure conditions.
- This feature also provides additional overall “bulk” to the seal. This improves sealing performance as well as enhancing the retention force at the interface between the adjoining pipe sections, which can be particularly important when larger radial clearance spaces between the male pipe spigot and the surrounding socket are involved.
- the stiffness of the seal will further increase non- linearly when the two halves of the rear portion on either side of the V-notch 12 come into contact with one another, thereby actively resisting further compression.
- the upper legs operate by a mechanism similar to that of the other seals.
- the underside of this version incorporates a circular profile and functions in a manner similar to that of a conventional O-ring seal.
- the groove in the pipe spigot would be relatively narrow in order to preserve pipe strength, but sufficiently deep to prevent rearward movement of the seal as the adjoining pipe sections engage during assembly.
- the seal is provided with increased thickness at the base to improve the initial "bulking" of the seal upon installation, and thereby increase the retention force, without compromising the intended sealing mechanism.
- the thickness of the neck region 14 has been increased, to enhanced the overall stiffness of the seal and to minimise the risk of either or both of the sealing lips or supporting portions inadvertently folding back during installation or under excess pressure conditions.
- the rearward leg 3 is significantly thicker and bulkier than the forward leg, so as to provide increased retention force and again to minimise the possibility of the associated lip from folding back onto itself.
- the overall shape, as well as the configurations of the individual constituent elements of the seal may be adjusted and optimised to suit the particular size of the pipe, the material properties of the seal, the nature of the pipe sections to be joined, the size of the clearance between them, the pressure conditions, and other operating parameters.
- the bridge section and associated neck region may be substituted by other forms of connection means.
- the seal may, for example, incorporate a fluid or a gel able to move between the first and second portions of the seal during compression and installation. Other arrangements based on mechanical movement, fluid pressure and the like are also contemplated.
- the seal according to this first aspect of the invention provides a number of important advantages. Firstly, it compresses radially far more easily than a conventional O-ring seal and therefore requires significantly less axial force on the adjoining pipe sections in order to install. At the same time, by virtue of the dual sealing rim arrangement and the synergistic interaction between them, sealing performance is substantially improved. Because the seal is pressure responsive, it can be used in relatively high pressure applications and because it is double sided, only one seal is required even in situations where the pressure within the pipe intermittently alternates between positive and negative values. The seal does not readily foul or move out of position during installation and once installed, cannot subsequently move out of position. Because the same seal configuration can be used in virtually any application, it substantially improves production efficiency and streamlines inventory control.
- the seal cannot easily inadvertently be installed in an incorrect orientation, which substantially eliminates the risk of operator error.
- the seal enables a smooth, substantially flush pipe connection both internally and externally, without the need for collars, flanges, or other external fittings. Not only does this produce a superior aesthetic result, also reduces inventory and manufacturing costs. Furthermore, it substantially reduces the thickness and depth of trenches required in the case of underground pipes, which in turn substantially reduces excavation and installation costs. In all these respects, this aspect of the invention represents a practical and commercially significant improvement over the prior art.
- this second aspect provides a mechanism to permit a limited degree of rotation between adjoining pipe sections, about an axis that is normal to the longitudinal axes of those sections.
- rotation is used to describe the situation where one pipe section is coupled to another (either by means of an external collar or by means of a male spigot formed on the end of one pipe section and a complementary female recess formed in the in the corresponding end of the next pipe section), and then moving the free end of the second pipe so that an included angle is formed between the axes of the adjoining pipes.
- This rotational capacity is of considerable benefit in that it avoids stress concentration and accumulation in the pipe joints in situations when the pipes are not - Im precisely axially parallel. Stress build-up in these circumstances can eventually cause pipes to crack.
- the invention provides a pipe system including a first pipe section 51 having a male end 52 and a second pipe section 53 having a female end 54 (see figures 19 to 23).
- the male and female ends are adapted for connection in overlapping relationship to join the pipe sections together.
- the connection is sealed using an angular pipe seal, which is preferably a double-acting K-seal of the type previously described (not shown for the sake of clarity in figures 20 to 26).
- the male pipe end 52 incorporates a first circumferential recessed channel 60, the function of which will be described more fully below.
- the male pipe end also incorporates a second circumferential recess, groove or channel 61, spaced forwardly of the first channel 60 toward the proximal end of the associated pipe section 51.
- the second channel 61 is adapted to locate the pipe seal in an overlapping region 62 between the male and female pipe ends in the assembled configuration.
- the second channel is therefore essentially analogous in structure and function to the circumferential groove 25 illustrated in figures 4 to 6 in connection with the first aspect of the invention.
- the male pipe end or spigot 52 also incorporates a circumferential parallel land 65 between the first and second channels 60 and 61.
- This land represents the section of maximum external diameter of the spigot, and thereby defines a zone of minimal radial clearance in the overlapping region 62 between the male and female pipe ends.
- the land section is therefore the part of the male pipe end upon which the female end will primarily bear, and its diameter is as close to the internal diameter of the surrounding female pipe end as process capabilities and manufacturing tolerances will allow, while still ensuring a clearance fit.
- the first channel 60 is configured to permit a limited extent of relative radial displacement of the female pipe end in response to axial misalignment between the pipe sections. Importantly, this allows the joint to accommodate a limited degree of relative rotational displacement about any axis normal to the longitudinal axes of the adjoining pipe sections. Because the parallel land section 65 is relatively short and constitutes the zone of minimal radial clearance in the overlapping region between the pipe ends, it allows this rotation to occur with minimal restriction in the manner of a pseudo "ball joint".
- the first circumferential channel or recess 60 between the land and the transitional shoulder between the spigot and the normal outer diameter of the pipe, allows the female pipe to rotate about the parallel land section, without coming into contact with the section of the spigot behind the seal (see figure 25). Without this recess, in order to accommodate the same degree of rotation, the radial clearance between the male and female pipe ends would need to be so great as to seriously compromise the performance of the seal.
- the channel 60 incorporated as described, the radial clearance between the male and female pipe ends in the region of the land can be minimised or substantially eliminated, thereby contributing greatly to seal location, retention and performance.
- a leading nose section 66 of the spigot disposed forwardly of the second channel adjacent the outer rim, has a diameter less than that of the land, and is formed to define a tapered, frusto-conical surface 68.
- This surface 68 is inclined at a specified angle, predetermined so as to provide or at least approximate surface-to-surface contact between the nose section 66 of the male pipe end and the surrounding inner surface of the female pipe end.
- the nose section reduces the effective length of the spigot in a rotational context, but without reducing the actual extent of overlapping engagement between the spigot and the surrounding female pipe end.
- the outer rim of the nose section is this chamfered so as to minimise contact pressure and avoid a relatively sharp spigot nip point at the limit of rotational displacement.
- a chamfer 69 on the inner peripheral edge of the female pipe end minimises stress concentrations in the first channel 60 and effectively avoids a relatively sharp socket nip point at the limit of rotational displacement.
- the chamfer 69 also provides a tapered lead into the female recess, and interacts with the tapered and chamfered end of the male spigot, to assist in positioning of the seal, and to accommodate a greater degree of rotation and axial misalignment, during installation.
- This feature is particularly advantageous because in practice, contractors often attempt to insert the male pipe into the female at an angle. The pipe is then typically rotated into an approximately parallel position, with the insertion and assembly being accomplished in effect, simultaneously. Without the tapered lead provided by a combination of the frusto-conical nose on the male spigot and the chamfer on the rim of the female socket, pipe assembly in this way is significantly restricted.
- a pressure seal of the type previously described in connection with the first aspect of the invention is particularly advantageous in conjunction with the pipe connection system according to this second aspect, because the neck region of the seal, between the base and the bridge section, readily deforms resiliently to accommodate the relative rotational displacement without compromising the performance or efficiency of the seal in any way.
- this seal is stably located and captively retained in its seat within the second circumferential groove, so as to minimise the likelihood of inadvertent dislocation during rotational movement between the adjoining pipe sections about a normal axis in the manner described.
- other seal arrangements such as O-ring and V-seals may alternatively be used.
- the pipe sections may be formed from any suitable material including most plastics, metals, concretes, terracottas, FRPs and the like.
- the pipe sections are formed from fibre reinforced cement (FRC), and the male and female end formations, including the various grooves, channels, chamfers and lands, are moulded or machined into the corresponding outer and inner surfaces of the respective ends of these sections.
- FRC fibre reinforced cement
- This material has been found to provide significant advantages in terms of strength, durability, versatility, impact resistance and resistance to corrosion and environmental degradation, as well as production cost.
- the preferred method of fabrication whereby the spigots and sockets are integrally formed with the pipe ends is particularly well adapted for use with relatively thick- walled FRC pipes.
- this method also obviates the need for separate collars and the like around the joints, which greatly reduces assembly time, facilitates the installation procedure, and further reduces inventory and production costs.
- the various features of the system as described could also be integrally formed by other fabrication methods suitable to the materials used for the pipes, or alternatively incorporated into collars or other supplementary fittings if required.
- the first and second pipe sections incorporating the fittings and features permitting rotational engagement as defined may not necessarily be in the form of substantially identical pipe sections joined in end to end relationship, but may alternatively, for example, be in the form of a pipe section and a collar, junction or other complementary component.
- the capacity to "rotate" one pipe relative to another is particularly useful in situations where a pipeline needs to be laid in bad soils, which include highly expansive soils such as black soil and marine silts, or in mine subsidence areas, for example.
- the capacity for a limited degree of pipe rotation in this sense is also of value where line deflection is needed in order to bring a pipeline around a relatively large radius corner.
- pipe rotational capacity can eliminate the need for additional fittings such as bends and junctions the resultant system is therefore cheaper, requires fewer components, and makes use of fewer joints, which ultimately leads to increase strength, capacity and reliability.
- Rotational capacity is also of benefit where a degree of flexibility in the pipeline adjacent rigid structures is required.
- a degree of flexibility in the pipeline adjacent rigid structures is required.
- a pipe is joined to a rigid structure such as a revetment wall, a manhole, a pit or the like
- it is of benefit if the system can rotate as the soil outside the rigid structure subsides over time, and the pipeline drops. In such circumstances, non-rotating joints are prone to failure at the juncture between the pipe and the adjoining structure.
- Increasing the rotational capacity of a pipe system is also advantageous in that greater rotation will facilitate shorter radius bends, and thereby allow for more versatility in application, which in turn enhances the marketability of the system.
- the present invention allows these various advantages to be obtained, in a system that is not inherently compromised in terms of the arrangement or performance of the pipe seals.
- the second aspect of the invention therefore also provides both practical and commercially significant improvements over the prior art, whether used in conjunction with the first aspect, or independently of it.
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Abstract
Description
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Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NZ524623A NZ524623A (en) | 2000-08-16 | 2001-08-15 | A seal and a pipe system allowing for misalignment |
AU2001281580A AU2001281580B2 (en) | 2000-08-16 | 2001-08-15 | A seal and a pipe system allowing for misalignment |
AU8158001A AU8158001A (en) | 2000-08-16 | 2001-08-15 | A seal and a pipe system allowing for misalignment |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AUPQ9458A AUPQ945800A0 (en) | 2000-08-16 | 2000-08-16 | A seal |
AUPQ9458 | 2000-08-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2002014719A1 true WO2002014719A1 (en) | 2002-02-21 |
Family
ID=3823513
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/AU2001/001014 WO2002014719A1 (en) | 2000-08-16 | 2001-08-15 | A seal and a pipe system allowing for misalignment |
Country Status (4)
Country | Link |
---|---|
AU (1) | AUPQ945800A0 (en) |
NZ (1) | NZ524623A (en) |
TW (1) | TW507056B (en) |
WO (1) | WO2002014719A1 (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1764533A2 (en) * | 2005-09-20 | 2007-03-21 | Bayer MaterialScience LLC | Gasket |
WO2010092024A1 (en) * | 2009-02-13 | 2010-08-19 | Valeo Systemes Thermiques | Seal |
EP2360410A1 (en) | 2010-02-12 | 2011-08-24 | Henn GmbH & Co.KG | Connector |
AT12491U1 (en) * | 2011-01-27 | 2012-06-15 | Henn Gmbh & Co Kg | POETRY |
CN109073081A (en) * | 2016-03-18 | 2018-12-21 | Gea机械设备有限公司 | Sealing system for being sealed to gap |
EP3564567A1 (en) * | 2018-04-30 | 2019-11-06 | Theodor Cordes GmbH & Co. KG | Sealing ring with support flag |
EP3862599A1 (en) * | 2020-02-07 | 2021-08-11 | ContiTech Techno-Chemie GmbH | Lamellar sealing ring with x-shaped cross-sectional geometry |
CN116702522A (en) * | 2023-08-08 | 2023-09-05 | 常州星宇车灯股份有限公司 | Method for detecting radius of chamfer surface of rubber groove of automobile lamp |
EP4296546A1 (en) * | 2022-06-22 | 2023-12-27 | Wagner International Ag | Seal for sealing a follow-up plate against a container and follow-up plate and conveyor with the seal |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7253429B2 (en) * | 2019-04-08 | 2023-04-06 | Tmtマシナリー株式会社 | Coupling device and spinning take-up equipment |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU1573523A (en) * | 1923-12-21 | 1925-01-06 | Hoskins Ikon and Stefl Company Limited | Improvements in or connected with cast iron steel and other pipes |
US2809853A (en) * | 1954-03-31 | 1957-10-15 | Hamilton Kent Mfg Company | Pipe and socket with flexible lip gasket |
FR1545368A (en) * | 1967-10-18 | 1968-11-08 | Sealing for sleeved pipes | |
US3698744A (en) * | 1971-01-06 | 1972-10-17 | Clow Corp | Axially locked pipe joint |
US4133563A (en) * | 1976-02-12 | 1979-01-09 | Sadayoshi Yamazaki | Pipe joint |
GB1555196A (en) * | 1976-04-05 | 1979-11-07 | Wolf Woco & Co Franz J | Spigot and socket pipe joints |
US4690414A (en) * | 1983-06-20 | 1987-09-01 | Mehren Rubber A/S | Means for sealing the gap between two axially displaceable sealing surfaces |
US4830408A (en) * | 1981-06-05 | 1989-05-16 | Dril-Quip, Inc. | Connector assembly |
-
2000
- 2000-08-16 AU AUPQ9458A patent/AUPQ945800A0/en not_active Abandoned
-
2001
- 2001-08-15 TW TW090119962A patent/TW507056B/en not_active IP Right Cessation
- 2001-08-15 NZ NZ524623A patent/NZ524623A/en unknown
- 2001-08-15 WO PCT/AU2001/001014 patent/WO2002014719A1/en active IP Right Grant
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU1573523A (en) * | 1923-12-21 | 1925-01-06 | Hoskins Ikon and Stefl Company Limited | Improvements in or connected with cast iron steel and other pipes |
US2809853A (en) * | 1954-03-31 | 1957-10-15 | Hamilton Kent Mfg Company | Pipe and socket with flexible lip gasket |
FR1545368A (en) * | 1967-10-18 | 1968-11-08 | Sealing for sleeved pipes | |
US3698744A (en) * | 1971-01-06 | 1972-10-17 | Clow Corp | Axially locked pipe joint |
US4133563A (en) * | 1976-02-12 | 1979-01-09 | Sadayoshi Yamazaki | Pipe joint |
GB1555196A (en) * | 1976-04-05 | 1979-11-07 | Wolf Woco & Co Franz J | Spigot and socket pipe joints |
US4830408A (en) * | 1981-06-05 | 1989-05-16 | Dril-Quip, Inc. | Connector assembly |
US4690414A (en) * | 1983-06-20 | 1987-09-01 | Mehren Rubber A/S | Means for sealing the gap between two axially displaceable sealing surfaces |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1764533A2 (en) * | 2005-09-20 | 2007-03-21 | Bayer MaterialScience LLC | Gasket |
EP1764533A3 (en) * | 2005-09-20 | 2007-08-29 | Bayer MaterialScience LLC | Gasket |
US7314590B2 (en) | 2005-09-20 | 2008-01-01 | Bayer Materialscience Llc | Method of preparing a coated molded plastic article |
WO2010092024A1 (en) * | 2009-02-13 | 2010-08-19 | Valeo Systemes Thermiques | Seal |
FR2942286A1 (en) * | 2009-02-13 | 2010-08-20 | Valeo Systemes Thermiques | SEAL |
EP2360410A1 (en) | 2010-02-12 | 2011-08-24 | Henn GmbH & Co.KG | Connector |
AT12491U1 (en) * | 2011-01-27 | 2012-06-15 | Henn Gmbh & Co Kg | POETRY |
CN109073081A (en) * | 2016-03-18 | 2018-12-21 | Gea机械设备有限公司 | Sealing system for being sealed to gap |
EP3564567A1 (en) * | 2018-04-30 | 2019-11-06 | Theodor Cordes GmbH & Co. KG | Sealing ring with support flag |
EP3862599A1 (en) * | 2020-02-07 | 2021-08-11 | ContiTech Techno-Chemie GmbH | Lamellar sealing ring with x-shaped cross-sectional geometry |
EP4296546A1 (en) * | 2022-06-22 | 2023-12-27 | Wagner International Ag | Seal for sealing a follow-up plate against a container and follow-up plate and conveyor with the seal |
CN116702522A (en) * | 2023-08-08 | 2023-09-05 | 常州星宇车灯股份有限公司 | Method for detecting radius of chamfer surface of rubber groove of automobile lamp |
CN116702522B (en) * | 2023-08-08 | 2023-10-31 | 常州星宇车灯股份有限公司 | Method for detecting radius of chamfer surface of rubber groove of automobile lamp |
Also Published As
Publication number | Publication date |
---|---|
TW507056B (en) | 2002-10-21 |
AUPQ945800A0 (en) | 2000-09-07 |
NZ524623A (en) | 2003-11-28 |
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