GASKETED SPECTACLE PLATE ASSEMBLY FOR INDUSTRIAL PIPE SYSTEMS

Abstract

A spectacle plate assembly and method for its production includes adhesively bonding a ring-shaped flexible sealing gasket to cover all, or substantially all of a contoured gasket receiving surface that is formed on both sides of the circular plate, the upper surfaces of the contoured gasket receiving surface lying above the plane of the surface of the adjacent plate to provide a unitary structure in preparation for positioning the plate between the opposing faces of a pair of stationary flanges.

Claims

1. A spectacle plate assembly comprising: a. a spectacle plate formed from a first circular solid or blind plate joined to a circular ring plate by a tie bar, where the opposing sides of each of the circular plates includes a grooved concentric contoured gasket receiving surface, the upper surfaces of which lie in a plane above the plane of the surrounding plate, and extend inwardly from a position proximate the peripheral edge of the plate a predetermined distance toward the center of the plate, the contoured gasket receiving surface being configured and dimensioned to receive a flexible sealing gasket that, in use, is positioned between opposing faces of stationary pipe flanges; b. a first adhesive composition applied to the contoured gasket receiving surfaces of each plate; c. a flexible sealing gasket configured and dimensioned to cover all, or substantially all of the respective contoured gasket receiving surfaces of the circular plates, the sealing gasket being securely bonded to the contoured gasket receiving surfaces of each plate, thereby providing a spectacle plate assembly that comprises a solid or blind plate and/or a ring plate having adhesively bonded and secured to their respective opposing contoured gasket receiving surfaces a sealing gasket that remains in place on the plate when the plate and gaskets are in a vertical or a horizontal orientation.

2. The spectacle plate assembly of claim 1 in which the contoured gasket receiving surface is grooved in accordance with ASME Standard 16.20 and lies above the plane of the surface of the adjacent plate.

3. The spectacle plate assembly of claim 1 in which the flexible sealing gasket is in the form of a unitary ring.

4. The spectacle plate assembly of claim 1 in which the flexible sealing gasket is formed from a plurality of arcuate sections corresponding to the receiving surface.

5. The spectacle plate assembly of claim 1 in which the adhesive bonding of the flexible sealing gasket resists displacement by a lateral force applied to the edge of the sealing gasket.

6. The spectacle plate assembly of claim 1 in which the flexible sealing gasket is graphite or polytetrafluorethylene (PTFE).

7. The spectacle plate assembly of claim 1 in which the thickness of the flexible sealing gasket is in the range of 0.4 mm to 0.7 mm.

8. The spectacle plate assembly of claim 1 in which the flexible sealing gasket is 0.5 mm thick.

9. A method of constructing a spectacle plate assembly that includes a spectacle plate formed from a first circular solid or blind plate joined to a circular ring plate by a tie bar, where the opposing sides of each of the circular plates includes a concentric contoured grooved gasket receiving surface extending inwardly a predetermined distance from a position proximate the peripheral edge of the plate toward the center of the plate, the respective upper surfaces of the contoured gasket receiving surface lying in a plane above the plane of the surrounding plate, the receiving surface being configured and dimensioned to receive a flexible sealing gasket that, in use, is positioned between opposing faces of stationary pipe flanges, the method comprising: a. applying an adhesive composition to the contoured gasket receiving surfaces of one or both of the circular plates; b. providing a pair of flexible sealing gaskets, each in the form of a ring that is dimensioned and configured to cover all, or substantial all of a receiving surface; c. contacting a surface of a flexible sealing gasket with the adhesive applied to each of the contoured gasket receiving surfaces to securely bond the flexible sealing gasket to the plate and thereby form a unitary spectacle plate assembly that can be positioned vertically between the opposing faces of stationary pipe flanges.

10. The method of claim 9 in which an adhesive composition is applied in the form of a spray.

11. The method of claim 9 which includes first applying a releasable masking composition to the surfaces of the plate adjacent the contoured gasket receiving surfaces to prevent the adhesive spray from contacting the adjacent surfaces.

12. The method of claim 11, where the masking composition is released by application of a solvent or by mechanical peeling of the mask from the surface of the plate.

13. The method of claim 9 in which each of the flexible sealing gaskets are bonded to one of the circular plates, in situ, while the plate is retained by the tie bar between the opposing surfaces of the stationary pipe flanges.

14. The method of claim 9 in which the adhesive composition is applied with a manual applicator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The improved method and system of the present disclosure will be described in further detail below and with reference to the attached drawings in which the same reference numerals are used to describe the same or similar elements:

[0025] FIGS. 1A and 1B are, respectively, side elevation and cut-away views illustrative of a typical spectacle blind and flange assembly of the prior art;

[0026] FIG. 2 is a top plan view of a typical spectacle plate of the prior art;

[0027] FIG. 3 is a top front perspective cross-sectional exploded view of a spectacle plate illustrating installation of sealing gasket of the present disclosure;

[0028] FIG. 3A is a detailed cross-sectional end view of the left end of the plate shown in FIG. 3;

[0029] FIG. 4 is a cross-sectional view of a spectacle plate similar to FIG. 3 showing the sealing gasket on the upper surface of the plate; and

[0030] FIG. 4A is an exploded detailed end view similar to FIG. 3A with the sealing gasket above the finished surface of the plate.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0031] As will be understood from the above description of FIG. 1A of the prior art that illustrates a typical installation of a blind spectacle plate between stationary opposed flanges, in order to rotate the specialized pipe fitting around the opening (18) in the tie bar (16) that joins the blind and ring plates (12, 14), it is necessary to loosen the securing nut (24) on its bolt (22), and to remove all of the other bolts from their positions extending between the flange faces (26a, 26b).

[0032] Referring now to FIG. 3, a sealing gasket (100) of the present disclosure is bonded to the upper contoured gasket receiving surfaces (50) of the ring plate (14). As best shown in FIGS. 3B and 4B, it will be seen that a plane defined by the top or high points of the contoured gasket receiving surface (50) lies above the plane of the surface of the surrounding plate (14). In an embodiment, the bottom of the grooves or lowermost contoured regions formed in the receiving surface lie in the plane of the surface of the plate.

[0033] In a preferred embodiment, the sealing gasket (100) is secured in place by spray adhesive (92) that is applied to the receiving surface (50) by an appropriate applicator (90) in an amount that is sufficient to maintain the gasket securely in position, without significantly modifying the contours of the receiving surface.

[0034] Suitable adhesives include multi-purpose commercial and industrial adhesives preferably applied in the form of a spray. The adhesive can most conveniently be applied to the grooved receiving surface of the plate in a viscosity that will avoid excessive flow, particularly when the plate is in the vertical position in the field. Some overspray beyond the perimeters of the grooved surface can be tolerated.

[0035] The specific adhesive material applied is selected with a view to eventually removing the adhesive when the gasket is to be replaced. For this reason, adhesives that are epoxy-based which form a very strong bond with the surface of the metal plate are less desirable. As is the practice in the prior art, when a new gasket is to be applied, the grooved surface must be prepared to provide a clean and uniform surface, typically by means of wire brushes and the like which will not damage the contours of the surface being prepared. Chemical solvents may also be used, depending upon the nature of the material to be removed.

[0036] The surface of the plate lying outside of the grooved surface to which the adhesive material is to be applied can be treated with an appropriate masking composition to prevent the adhesive spray from making direct contact with the adjacent metal surfaces. The masking material is applied prior to the application of the spray adhesive by placing an impermeable barrier over the receiving surface that can easily be removed after application of the adhesive. The mask can be a polymer that is easily stripped from the metal surface of the plate.

[0037] The viscosity of the liquid adhesive should be such that will be subject to minimal flow from the point of application so that the receiving surface can be uniformly coated with a sufficient amount of the adhesive to secure the sealing gasket (100) in place after it has been positioned. Thus, the bonding agent should have sufficient tack to maintain the sealing gaskets in position on both sides of the spectacle plate when it is rotated into position between the faces of the flanges. The selection of adhesives having the required properties as described above is within the skill of the art.

[0038] From the above description, it will be understood that the characteristics of the sealing gasket include a tensile strength value sufficient to resist damage and/or deformation when cut from a sheet or a web to form the ring, or sections of a ring that correspond to the receiving surfaces of the plate, and also during its manual installation in the field when the plate is in a vertical position. In this regard, it is to be understood that the sealing gasket can alternatively be applied incrementally in smaller arcuate sections to cover the plate's receiving surfaces, rather than as a complete one-piece ring.

[0039] Other properties of the material from which the sealing gasket is derived include resistance to chemicals that are present in the fluid(s) in the pipeline and in the facility where the gaskets will be used, as well as compatibility with the adhesive(s) that will be applied. The adhesive material should be fire resistant and preferably not flammable; and it should not be adversely affected by temperatures to which the material will be exposed during use.

[0040] It has been found that suitable commercially available materials for fabricating the sealing gasket (100) include graphite and polytetrafluorethylene (PTFE) in sheet form ranging in thickness from 0.4 mm to 0.7 mm. A preferred thickness of the flexible sealing gasket material is 0.5 mm.

[0041] In most installations, the ring plate will be in position to permit the continuous flow of fluid through the piping system and the opposite blind plate will typically be exposed to the elements for relatively long periods of time. Under such operating conditions, it will be understood that the sealing gaskets of the present disclosure will be installed at such time as preparations are made for the changing of the position of the spectacle blind plate fitting to seal the flanges against fluid flow. Routine cleaning of the respective grooved receiving surfaces in the plates will be performed as necessary to restore the surfaces (50) before the sealing gaskets (100) are bonded in place.

[0042] If the spectacle plate has been stored at a location in a protected environment, e.g., inside of a building, the seals can be installed on the spectacle plate receiving surface when the plates are fabricated, or during their storage prior to installation, or in a maintenance facility in close proximity to the time and place of their installation.

[0043] The same or different types of adhesive can be applied to the spectacle plates if the sealing gaskets are to be assembled prior to storage for a significant period of time. For example, a different adhesive composition may be preferable for securing the sealing gasket to the plate in the field.

[0044] In a further embodiment, the sealing gasket can be produced in a range of sizes to meet the known ASME specifications of a number of spectacle plates of varying diameter. Costs can be minimized by cutting a series of circular seals of decreasing diameters from a single, large sheet of the gasket material.

[0045] The sealing gasket can also be pre-coated on one side with an adhesive material to which is applied a manually removable protective release layer of, e.g., coated paper, a polymeric film, or the like to form a robust laminate that can be packaged and shipped for later use in the field or in a protected facility as described above. The protective release layer can be marked or otherwise provided with indicia to facilitate their correct positioning on the grooved receiving surfaces. They will be manually removed at the time of installation on the plate.

[0046] From the above, it will be understood that a method is provided for constructing a spectacle plate assembly that includes a spectacle plate formed from a first circular solid or blind plate joined to a circular ring plate by a tie bar, where the opposing sides of each of the circular plates includes a grooved concentric contoured gasket receiving surface, the upper surface of the grooves lying in a plane above the plane of the surrounding plate and extending inwardly a predetermined distance from a position proximate the peripheral edge of the plate toward the center of the plate, the contoured gasket receiving surface being configured and dimensioned to receive a sealing gasket that, in use, is positioned between opposing faces of stationary pipe flanges, where the method includes the following steps: [0047] a. providing a sealing gasket in the form of a ring that is dimensioned and configured to cover all, or substantial all of the grooved receiving surface; [0048] b. applying an adhesive composition to a side of the sealing gasket; [0049] c. providing the adhesive on the sealing gasket with a manually removable protective release cover to isolate the adhesive composition, to thereby provide an adhesive-coated ring-shaped sealing gasket with a protective release cover that can be stored and transported for later use; [0050] d. providing a pair of ring-shaped sealing gaskets prepared in accordance with steps (a)-(c) for use with a spectacle plate secured between a pair of flanges; [0051] e. manually removing the release cover from the adhesive on one of the ring-shaped sealing gaskets and affixing and securely bonding it to the grooved receiving surface on one side of a spectacle plate; and [0052] f. repeating step (e) on the opposite side of the spectacle plate to thereby provide a unitary spectacle plate assembly with integrated sealing gaskets for placement between the opposing flange faces.

[0053] Practice of this method will further reduce the time required to complete the assembly in situ, i.e., in the field at the precise location of the pipe flanges where the spectacle plate is installed. The use of film seals that are precoated with the appropriate adhesive and release layers will minimize the risk and damage to gaskets and contribute to ease of installation.

[0054] As will be seen from the above detailed description, the present method and system provides the advantages of reducing the time for changeover and installation of the spectacle plate, assures a secure and fluid-tight seal, and avoids the risk of loss and/or damage to the gasket.

[0055] While the novel sealing gasket of this disclosure and its method of manufacture and use with spectacle plates have been described in detail above, other modifications and adaptations rill be apparent to those of ordinary skill in the art, and the scope of protection for the invention is to be determined by the claims that follow.