Swivel misalignment coupling for connecting conduit sections

A swivel misalignment coupling for connecting pipe sections in a high-pressure conduit. In one embodiment, the coupling is a three-bolt coupling having a female coupling member, a male coupling member, and a swiveling collar member. The male and female coupling members have contact surfaces that are spherical to enable sealing contact between them. A seal ring may be positioned between the contact surfaces to ensure a good seal. The collar swivels around the male coupling member to facilitate fastening of the collar to the female coupling member, which holds the male and female coupling members in sealing engagement. Recesses may be positioned radially inward from the attachment points (e.g., bolt holes) of the female coupling member to reduce stress and potential deformation of the contact surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention may become apparent upon reading the following detailed description and upon reference to the accompanying drawings.

FIGS. 1A and 1Bare diagrams illustrating an exemplary implementation of a conduit system in accordance with one embodiment.

FIG. 2is a diagram illustrating a multi-section conduit using three-bolt swiveling misalignment connectors in accordance with one embodiment.

FIG. 3is a diagram illustrating the structure of a three-bolt swiveling misalignment connector as used in the example ofFIG. 2.

FIGS. 4A and 4Bare diagrams illustrating the male coupling member ofFIG. 3separately.

FIGS. 6A and 6Bare diagrams illustrating the female coupling member ofFIG. 3separately.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

As described herein, various embodiments of the invention comprise conduit systems and couplings for conduits, wherein the couplings are configured to facilitate easy and reliable connections of potentially misaligned conduit sections.

There are many applications for high-pressure and/or high strength conduits, particularly in the chemical and oil processing industries. The fluids that are conveyed by these conduits may be very hazardous. For instance, the fluids may be corrosive, poisonous, or harmful to the environment. Additionally, the fluids may be carried through the conduits at very high pressures or very high temperatures, making them even more dangerous if the conduits leak.

Various types of couplings have been developed to enable reliable connections to be formed between sections of high strength conduits. Typically, these connections are made by welding heavy flanges to the ends of the conduit sections and then bolting the flanges together with a gasket or seal between them. Often, the flanges are immovable, and a good seal can only be formed between the flanges if the sealing faces of the flanges are properly positioned and precisely aligned. In some applications, however, it is necessary to use many different conduit sections, or to install the conduit sections around other equipment, both of which make it difficult to accurately position or align all of the conduit sections so that good seals between the conduit sections can be ensured.

Misalignment couplings have been developed for some applications. These misalignment couplings are typically used to couple large diameter pipe sections, such as oil pipelines. Conventional misalignment couplings are typically very bulky devices that are secured by bolting together heavy flanges around the peripheries of the couplings' components. Conventional misalignment couplings are therefore normally very large, heavy devices that require a great deal of time and effort to assemble and thereby join the conduit sections. Consequently, these misalignment couplings are not well suited for use in conduit systems that use smaller-diameter (but still high-strength and/or high-pressure) conduits and require assembly of many different conduit sections.

It would therefore be desirable to provide systems and methods for coupling conduit sections together, wherein the couplings between the conduit sections have sufficient strength to provide reliable seals between potentially misaligned sections of conduit in a high-strength and/or high-pressure system, and wherein the couplings are configured to be lightweight and easily assembled.

Referring toFIGS. 1A and 1B, an exemplary implementation of a conduit system in accordance with one embodiment is shown. In this embodiment, the conduit system is used to interconnect various components of a truck-mounted fluid processing system.FIG. 1Ashows the left side of the system andFIG. 1Bshows the right side of the system.

Fluid processing system100is mounted on a truck110to enable the system to be easily transported. The truck-mounting of the system, however, places several constraints on the design of the system. For instance, because of the limited amount of space on the truck, the system must be designed to be as compact as possible. The components must therefore be placed very close to each other, and the interconnecting conduits must be routed around components that might not otherwise be in the way in a stationary (non-truck-mounted) implementation. Further, the components may not be as precisely positioned when mounted on the truck, so the conduits need to be able to account for potentially greater mis-positioning or misalignment than in a stationary implementation. Still further, the capacity limitations of the truck demand that the interconnecting conduits be as light as possible.

In the embodiment ofFIGS. 1A and 1B, two exemplary conduit sections are illustrated—one on the left side of the system and one on the right side of the system. On the left side of the system, conduit150connects an input manifold120to a main fluid processing component130. On the right side of the system, conduit160connects main fluid processing component130to output manifold121. Because output manifold120cannot be precisely positioned with respect to the input of processing component130, conduit150includes multiple conduit sections that are connected by corresponding couplings in order to allow the conduit to be securely connected to form a leak-free conduit. Conduit150includes four sections,151-154. Section151is rigidly coupled to input manifold120, while section154is rigidly coupled to processing component130. Conduit sections152and153are coupled together between sections151and154using couplings155-157that provide secure connections between the sections, even when they are misaligned.

Similarly, because the output of processing component130and the input of manifold121cannot be precisely positioned, conduit160includes multiple sections that are coupled together to allow secure connection of the conduit. Conduit sections161-164are coupled together using couplings165-168. These couplings allow the conduit sections to be securely coupled together despite potentially being misaligned. It should be noted that conduits150and160may need to have multiple sections in order to allow inclusion of special-purpose conduit sections such as section164, which includes conduit branches170and171and corresponding valves.

Referring toFIG. 2, a multi-section conduit using three-bolt swiveling misalignment connectors in accordance with one embodiment is shown in more detail. In this embodiment, conduit200includes two conduit sections (210,211) and three couplings (220,221,222). Coupling221allows conduit sections210and211to be misaligned with respect to each other. Couplings220and222allow conduit200to be misaligned with respect to the components that are interconnected by the conduit. These may, for example, be functional components or additional conduit sections.

Couplings220-222are three-bolt swiveling misalignment connectors. As described above, the misalignment feature allows the conduit sections to be securely connected and to have good seals even though the ends of the conduit sections are not precisely aligned with each other. Each coupling uses three bolts, equally spaced around the periphery of the coupling to secure the two flanges of the coupling together. The use of only three bolts allows the coupling to be quickly assembled or disassembled. This is important in systems that include many different conduit sections and that may have to be frequently assembled or disassembled, such as for maintenance purposes. The three-bolt connection also reduces the weight of the coupling in comparison to more conventional couplings that use more bolts and require heavier flanges. The coupling is designed so that at least one of the flanges of the coupling can swivel around the end of the corresponding conduit section. This facilitates alignment of the bolt holes in the two flanges so that the coupling can be quickly and easily assembled.

Referring toFIG. 3, the structure of a three-bolt swiveling misalignment connector as used in the example ofFIG. 2is shown in more detail. In this example, coupling300includes a female coupling member310, a male coupling member320and a swiveling flange or collar330. Female coupling member310is configured so that a rear end311of the member can be welded to a first conduit section. Likewise, the rear end321of male coupling member320is configured to be welded to a second conduit section. Female coupling member310has a pocket that is formed by an inward-facing contact surface312. Male coupling member320has a nose formed by outward-facing contact surface322. The nose of male coupling member320fits into the pocket of female coupling member310. In this embodiment, each of contact surfaces312and322is spherically shaped so that contact between the surfaces can be maintained when the coupling members are misaligned. A seal ring340may be positioned between the contact surfaces in order to ensure a good seal between the flanges. Seal ring340may be a simple o-ring, a tapered seal ring (see U.S. Pat. No. 4,452,474), or any other suitable type of seal ring.

Male coupling member320has a shoulder323which extends radially outward from the member. Collar330is positioned around male coupling member320so that it abuts a rearward-facing (with respect to the male coupling member) surface of shoulder323. Collar330is then bolted to female coupling member310, pulling the collar toward the female coupling member and thereby forcing male coupling member320toward the female coupling member. The bolts are tightened to apply contact pressure between the contact surfaces of the male and female coupling members (or between these contact surfaces and the corresponding contact surfaces of the seal ring positioned between the contact surfaces). In order to accommodate misalignment of the coupling members, the bolt holes (e.g.,392) may be slightly oversized and both the bolts (e.g.,390) and nuts (e.g.,391) and seats therefor may be slightly rounded.

It should be noted that terminology used herein such as “radial” directions and “inward-facing” and “outward-facing” surfaces should be referenced with respect to the axis350at the centerline of the respective component. It should also be noted that, for each of the coupling members, “rear” refers to the end of the coupling member that is configured to be welded or otherwise connected to the corresponding conduit section, while “forward” refers to the end of the coupling member (398,399) that is farthest from this conduit.

Referring toFIGS. 4A and 4B, male coupling member320is shown separately.FIG. 4Ais a view of male coupling member320along the axis (centerline) of the member. From this view, it can be seen that male coupling member320is generally annular in shape and has no protruding tangs around the periphery of the member for bolting it to the female coupling member.FIG. 4Bis a cross-sectional view of male coupling member320showing the structure of the coupling member. As noted above, an outward-facing contact surface322is configured to contact the female coupling member (or a sealing ring between the male and female coupling members) to provide a sealing connection between them. Contact surface322is spherical in this embodiment, but may have other shapes in alternative embodiments. In this embodiment, shoulder323extends radially outward beyond contact surface322to form a stop326that limits the axial misalignment between the male and female coupling members. (At approximately 10° in misalignment in this embodiment, the stop contacts the female coupling member and prevents further misalignment.) In addition to forming stop326, shoulder323forms a rear contact surface325. When collar330is positioned around male coupling member320, the collar contacts surface325of the coupling member and applies pressure to this surface to urge the male coupling member into contact with the female coupling member.

Referring toFIGS. 5A and 5B, collar330is shown separately.FIG. 5Ais a view of collar330along the axis of the collar, whileFIG. 5Bis a cross-sectional view of the collar. Referring toFIG. 5A, it can be seen that, in contrast to the male coupling member, collar330has a flange with three tangs331-333extending radially outward, each having a bolt hole therethrough. The tangs enable the collar to be bolted to the female coupling member. Collar330includes a contact surface334or that comes into contact with rear contact surface325of male coupling member320and urges the male coupling member into contact with the female coupling member when the coupling is assembled. When the collar is positioned around the male coupling member, the coupling member can rotate or swivel within the collar and is not impeded by the bolts that connect the collar to the female coupling member. The collar can therefore be swiveled and aligned with the bolt holes of the female coupling member without having to move the male coupling member or the conduit section welded to the male coupling member.

Referring toFIGS. 6A and 6B, female coupling member310is shown separately.FIG. 6Ais a view of female coupling member310along the axis of the coupling member, andFIG. 6Bis a cross-sectional view of the female coupling member.

Referring toFIG. 6A, it can be seen that female coupling member310, like collar330, has a flange, including three tangs313-315extending radially outward from the flange, with both holes therethrough (e.g., bolt hole336, having center335). The flange and tangs are stationary with respect to female coupling member310, in contrast to the flange of collar330, which swivels around male coupling member320. The tangs and bolt holes female coupling member310are evenly spaced around the periphery of the coupling member so that they can be aligned with the bolt holes of the collar for assembly of the coupling.

Referring toFIG. 6B, female coupling member310has an inward-facing contact surface312configured to contact the male coupling member and thereby provide a sealing connection between the coupling members. In this embodiment, there is a recess in contact surface312in which a sealing ring360can be seated to provide a good seal between contact surface312of the female coupling member and contact surface322of the male coupling member.

FIGS. 6A and 6Balso show that each tang (313,314,315) of female coupling member310has a generally triangular-shaped recess (316,317,318) therein. In a conventional coupling, the flange is larger and accommodates more bolts (e.g., typically at least six) positioned around the periphery of the flange. The greater number of bolts are used not simply to provide sufficient contact pressure between the contact surfaces of the coupling components, but also to the evenly distribute the contact pressure around the peripheries of components.

Because only three bolts are used in this embodiment, there could be an uneven distribution of contact pressure around the contact surfaces of the coupling member if the thickness of the flange were the same across the entirety of each tang. In other words, the bolts could apply pressure at the three tangs, causing inward deformation of the female contact surface312near the tangs so that this contact surface does not meet the tolerances required for a good seal. The coupling could therefore leak. By providing the triangular recesses between the tangs and the contact surface, the tangs are allowed to flex somewhat without deforming the contact surface inward at those points. The greater thickness around the outer edge of the flange (e.g., at tangential portion319) or helps to transfer contact pressure to points between the tangs. Recesses316-318thereby reduce stresses and resulting deformation of the female contact surface and improve the seal produced by the coupling.

It should be noted that it is not necessary in this embodiment to provide recesses in the tangs of collar330because deformation of the collar that may be caused by the tightening of the bolts in the assembled coupling may affect contact between the collar and the shoulder of male flange320, but little, if any, of this deformation is transferred to contact surface322of the male flange.

It is contemplated that various embodiments of the present coupling are suitable for high-pressure conduits (e.g., conduits that must be pressurized to over 200 psi). Some embodiments of the coupling may withstand internal pressures of over 1000 psi. The high-pressure performance of the present coupling is therefore comparable to conventional high-pressure couplings. Both of these types of couplings are typically forged and/or machined, in contrast to the type of stamped-metal fixtures used in common low-pressure plumbing applications. The present coupling may be employed in a variety of applications ranging from smaller diameter pipes (e.g., 3 inch diameter) to larger pipelines (over 10 inches in diameter), similar to larger high-pressure pipe flanges. As noted above, however, the present coupling provides the advantage of easy assembly because the coupling is lighter, has fewer bolts than conventional couplings, and swivels. Further, the coupling allows connections of conduits in applications in which tight positioning and alignment tolerances may not be met using conventional couplings.

It should be noted that, while the foregoing description focuses on an exemplary embodiment that uses bolts to fasten the flange of the female coupling member to the flange of the swiveling collar, alternative embodiments may employ other types of fasteners. For instance, rather than providing bolt holes at the attachment points (tangs) of the flanges, the attachment points may be configured to be fastened together by clamps. Still other fasteners may also be used.

It should be noted that references herein to conduits and pipes should be construed interchangeably, and should further be construed to include types of conduits that are not simple tubular members. For example, manifolds, valve bodies and other components through which fluid may flow are considered to be conduits or pipes for the purposes of this disclosure.