GB2133083A

GB2133083A - Scored rupture disk apparatus

Info

Publication number: GB2133083A
Application number: GB08334058A
Authority: GB
Inventors: Sam Au Ou
Original assignee: BS&B Safety Systems LLC
Current assignee: BS&B Safety Systems LLC
Priority date: 1982-12-27
Filing date: 1983-12-21
Publication date: 1984-07-18
Also published as: GB2133083B; DE3346851A1; FR2538494B1; IT1168745B; FR2538494A1; JPS59133879A; CA1229540A; GB8334058D0; IT8324405A0

Abstract

A scored rupture disk apparatus including one or more scores (32) defining one or more blowout portions (42) therein, which remain attached to the apparatus by one or more unscored areas (44) which act as hinges upon the rupture of the disk, the disk including at least two portions of different thickness, the portion of lesser thickness including said one or more scores defining the one or more blowout areas and the thicker portion or portions of the apparatus, which may be provided by a separate supporting member attached, e.g. by welding, to the disk, having the unscored areas which act as hinges therein. <IMAGE>

Description

SPECIFICATION Scored rupture disk apparatus The present invention relates to improved scored rupture disk apparatus.

Commonly, such apparatus include one or more rupture disks which are supported between a pair of supporting members or flanges which are connected to a vessel or system containing fluid under pressure, the disks rupturing when excess fluid pressure occurs in the vessel or system.

Most rupture disks include annular flat flange portions to facilitate clamping between supporting members or flanges and concave-convex central dome portions which rupture when excess fluid pressure is exerted on the disks.

In operation of conventional rupture disks, fluid pressure is exerted on one side of the disks and the disks rupture in tension. In operation of reverse buckling rupture disks, fluid pressure is exerted on the convex side of the dome portions, which are thus placed in compression, and upon failure, the dome portions reverse and then ruptures.

Metal rupture disks have often included one or more scores on a surface thereof, usually the dome portion, and which create lines of weakness in the disks, so that upon rupture, the disks tear along the scores which define blowout portions which remain attached to the disks by unscored areas which act as hinges upon the rupture of the disks. Examples of such scored disks are described in U.S. Patent Nos. 3,005,573; 3,484,817 and 3,834,580.

Known scored rupture disks have been utilized successfully, but only when the fluid pressure at which the disks are designed to rupture is not extremely low or extremely high. For extremely low pressure applications the disk materials would have to be extremely thin, thus making the disks readily susceptible to damage and in applications where reverse pressure is created in the system being protected, i.e. a vacuum, special vacuum supports must be utillized to prevent their premature failure.

In extremely high pressure applications, scored rupture disks are not suitable because the disks are not strong enough to resist the tearing of parts therefrom by the violent flow of fluids through the disks after rupture.

According to the present invention there is provided a scored rupture disk having one or more scores on a surface thereof-defining one or more blowout portions which remain attached to said disk upon the rupture thereof, said rupture disk including at least two portions of different thickness, a portion of lesser thickness including said one or more scores thereon defining said one or more blowout portions and leaving an unscored area or areas which act as a hinge or hinges between said blowout portion or portions and the remainder of said disk upon the rupture of said disk and a thicker portion of said disk including said unscored areas which act as hinges, Such apparatus can be utilized in extremely low pressure applications without being readily susceptible to damage and without requiring ancillary vacuum support apparatus and can be utilized in extremely high pressure applications without the tearing away of parts occurring upon rupture.

In order that the invention may more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawings, in which: Figure 1 is a side cross-sectional view of one form of the apparatus of the present invention clamped between inlet and outlet supporting members; Figure 2 is a cross-sectional view taken along line 2-2 of Figure 1; Figure 3 is a side cross-sectional view similar to Figure 1 but showing the apparatus of the present invention after the rupture thereof; Figures 4 and 5 are side cross-sectional views of two other forms of the apparatus of the present invention; Figures 6, 7, 8, 9, 10, 12 and 14 are plan views of six further forms of apparatus of the present invention;; Figures 11, 1 3 and 1 5 are cross-sectional views taken along line 11-11, 13-13 and 1 5-1 5 of Figures 10, 12 and 14, respectively.

Referring now specifically to Figures 1-3, the illustrated apparatus 10 is shown clamped between a pair of pipe flanges 12 and 14 with gaskets 1 6 and 1 8 positioned between the apparatus 10 and the seating surfaces of the flanges 12 and 14. The flanges 12 and 14 are clamped against the apparatus 10 and gaskets 1 6 and 18 by a plurality of studs 20 which are disposed in complementary openings in the flanges 12 and 14 and by nuts 22 threadedly attached to the studs 20.

The inlet flange 12 is connected either directly or by a conduit (not shown) to a vessel or system containing fluid under pressure. The outlet flange 14 can be left open to the atmosphere or can be sealingly connected to a conduit (not shown) which leads pressurized fluids relieved through the apparatus 10 to a vent or a storage or reprocessing location. The apparatus 10 comprises a rupture disk 24 of substantially uniform thickness and a reinforcing member 26 also of substantially uniform thickness rigidly attached to the rupturable disk 24 on the inlet side. The rupture disk 24 includes an annular flat flange portion 28 connected to a central concaveconvex dome portion 30 positioned with the concave surface thereof facing the inlet flange 1 2.

The concave-convex dome portion 30 includes a single continuous score 32 formed on the concave surface thereof which defines a substantially circular blowout portion 34 and leaves an unscored area 36 thereon which acts as a hinge between the blowout portion 34 and the remaining portion of the disk 24 upon the rupture thereof (see Figure 3).

The reinforcing member 26 comprises an annular flat flange portion 40 of the same size and shape as flange portion 28 and a concave-convex portion 42 connected to flange portion 40 by a solid connecting portion 44. As best shown in Figure 2, the reinforcing member 26 is orientated with respect to disk 24, so that the connecting portion 44 is positioned adjacent and reinforces the unscored area 36 of the rupture disk 24. The central portion 42 of the reinforcing member 26 includes an arcuate slot 45 positioned to overlie and expose all of the score 32 in the rupture disk 24.

The convex surface of portion 42 of the same shape as the concave surface of portion 30 of the rupture disk 24, so that the concave-convex portions of the reinforcing member and rupture disk fit in nesting relationship, in which they are rigidly attached by a plurality of spot welds 46, or other attachments. The apparatus 10 thus includes portions of two thicknesses, the portion of least thickness (the rupture disk 24) including the scores 32, and the thickest portion (the rupture disk 24 together with the reinforcing member 26) including the unscored areas which act as hinges.

As seen in Figure 3, in operation of the apparatus 10, when fluid pressure from the vessel or system being protected exceeds the pressure at which the apparatus 10 is designed to rupture, the rupture disk 24 tears along the line of weakness therein formed by the score 32 and the force of fluid relieved by the rupture of the apparatus 10 flowing therethrough bends the blowout portion 34 of the rupture disk 24 as well as the central portion 42 of the reinforcing member 26 on the hinge comprised of the unscored portion 36 of the disk 24 and the connecting portion 44 of the reinforcing member 26. Thus, the blowout portion 34 and central portion 42 thereof remain attached to the annular flat flange portions of the disk 24 and reinforcing member 26.As indicated previously, if reverse pressure is exerted on the apparatus 10, i.e. the pressure exerted on the rupture disk 24 by way of the outlet flange 14 is greater than the pressure exerted on the rupture disk 24 and reinforcing member 26 by way of the inlet flange 12, damage to including the reversal of the apparatus 10 does not take place due to the presence of the reinforcing member 26 therein.

In Figure 4, apparatus 50 is shown which is identical to the apparatus 10 except that the reinforcing member 52 is positioned on the outlet side of the rupture disk 54 which includes a single score 56 defining a substantially circular blowout portion. The reinforcing member 52 is identical in configuration to the reinforcing member 26 of the apparatus 10 and is spot welded to the convex side of the rupture disk 54 by a plurality of spot welds 58.

In Figure 5, apparatus 60 includes a rupture disk 62 identical to the rupture disk 24 of the apparatus 10, and has a single score 64 defining a substantially circular blowout portion. First and second reinforcing members 66 and 70 are respectively attached by spot welds 68 to the concave side and by spot welds 72 to the convex side of the rupture disk 62.

The selection of a particular form of the apparatus of this invention as illustrated in Figures 1-5 depends on various factors, such as the design rupture pressure of the apparatus, whether the pressurized fluid is corrosive, etc. When the pressurized fluid is corrosive, the arrangement of Figure 4 would most likely be used rather than that illustrated in Figures 1-3 to place the reinforcing member out of contact with the corrosive fluid. In extremely high pressure applications, the arrangement of Figure 5 would be used to provide extra reinforcement to the hinge. While the apparatus illustrated in Figures 1, 2, 4 and 5 have been described as conventional types of rupture disk apparatus, i.e. rupturing in tension, it is to be understood that apparatus of the same configurations, shapes and with the same arrangements of parts can be designed for and used as reverse buckling apparatus.

In Figure 6 an apparatus 80 is illustrated which includes a rupture disk 82 having a score 84 thereon forming a substantially circular blowout portion therein. A reinforcing member 86 is provided which includes a central portion 88 attached to the rupture disk 82 by a plurality of spot welds 90. The central portion 88 of the reinforcing member 86 is in the form of a cross rather than being circular.

In Figure 7 apparatus 100 is illustrated which includes a rupture disk 102 and a reinforcing member 104 having a central portion 106. The central portion of the reinforcing member 106 is of a different shape from the apparatus of Figure 6.

In Figure 8 an apparatus 110 is illustrated including a rupture disk 112 and a reinforcing member 114 which has a central portion 11 6. The central portion 11 6 of the reinforcing member 114 is of yet a different shape.

In Figure 9, an apparatus 120 is illustrated which includes a rupture disk 122 and a reinforcing member 124 having a central portion 126. The rupture disk 122 includes a single score 128 defining a blowout portion of substantially rectangular shape. The central portion 126 of the reinforcing member 124 is also of substantially rectangular shape.

The selection of a particular form of the apparatus illustrated in Figures 6-9 or other forms depends on various factors such as the particular metal from which the apparatus is formed, manufacturing economy, ease of manufacture, etc.

Referring now to Figures 10 and 11, the illustrated apparatus 130 differs from the apparatus of Figures 1-9 in that it is comprised of a single integral part having two portions of different thickness, rather than two welded or attached parts. A rupture disk 1 32 having an annular flat flange portion 134 and a central concave-convex dome portion 136 is provided with a recess 1 38 in the concave side of dome portion 136 and the ends of the recess 1 38 are spaced apart to provide an area which does not include a recess therein. Thus, a circular interior portion is defined by the recess 1 38 in the concave-convex dome portion 1 36 and the area which is not recessed defines a hinge between the interior portion and the annular flat flange portion 134 of the disk.Disposed in the bottom of the recess 1 38 is a score 140, defining a substantially circular blowout portion in the concave-convex dome portion 136, the ends of which terminate near the ends of the recess 138.

Referring now to Figures 12 and 13, the apparatus comprises a single rupture disk 1 52 having an annular flat flange portion 1 54 and a concave-convex dome portion 1 56. Intersecting recesses 1 58 and intersecting scores 1 60 form overlying crosses in the concave-convex dome portion 1 56 defining four substantially triangular blowout portions therein.The operation of the apparatus 1 50 is similar to the operation of the apparatus 1 30 except that upon rupture, the concave-convex dome portion 1 56 of the apparatus 1 50 tears along the lines of weakness created by the scores 1 60 and opens in four triangular petals which bend at the unscored and unrecessed areas between the outer ends of adjacent recesses and scores.

The apparatus 180 of Figures 14 anu 1 5 comprises a single rupture disk 182 having an annular flat flange portion 1 84 and a concaveconvex dome portion 1 86. Intersecting recesses 1 88 and intersecting scores 1 90 which define substantially half-moon shaped blowout portions in the dome portion 186. The operation of the apparatus 180 is similar to the operation of the apparatus 130 except that upon rupture, the concave-convex dome portions 186 of the apparatus 1 80 tears along the lines of weakness created by the scores 1 90 and opens in two halfmoon shaped petals which bend at the unscored and unrecessed areas between the outer ends of adjacent recesses and scores.

It can be seen that the rupture disk apparatus of the present invention can be of the conventional type and can be flat or contain a concave-convex dome portion, or the apparatus can be of the reverse buckling type including a concave-convex dome portion. The reinforcing member can be formed of a separate part and rigidly attached to the rupture disk or the reinforcing portion of the apparatus can be an integral portion thereof. The reinforcing member or portion of the apparatus can be on either the inlet or outlet side or both sides of the rupture disk as can the score or scores thereon. The scores or scores and recesses of the apparatus can define one or more blowout portions of various shapes, e.g. substantially circular, substantially rectangular, substantially triangular.

Claims

1. A scored rupture disk having one or more scores on a surface thereof defining one or more blowout portions which remain attached to said disk upon the rupture thereof, said rupture disk including at least two portions of different thickness, a portion of lesser thickness including said one or more scores thereon defining said one or more blowout portions and leaving an unscored area or areas which act as a hinge or hinges between said blowout portion or portions, and the remainder of said disk upon the rupture of said disk and a thicker portion of said disk including said unscored areas which act as hinges.

2. A rupture disk according to claim 1, wherein said one or more scores define at least one substantially circular blowout portion.

3. A rupture disk according to claim 1, wherein said one or more scores define at least one substantially rectangular blowout portion.

4. A rupture disk according to claim 1, wherein said one or more scores define at least one substantially triangular blowout portion.

5. A rupture disk according to any preceding claim, wherein said rupture disk includes two portions of different thickness, the portion of lesser thickness including said one or more scores thereon and being comprised of a disk of substantially uniform thickness and the thicker portion being comprised of said disk and a separate reinforcing member of substantially uniform thickness attached to one side of said disk.

6. A rupture disk according to claim 5, wherein a further reinforcing member of substantially uniform thickness is attached to the opposite side of said disk.

7. A rupture disk according to claim 5 or 6, wherein said reinforcing member or members are spot-welded to said disk.

8. A rupture disk according to claim 5, 6 or 7, wherein said reinforcing member or at least one of said reinforcing members are formed with a slot overlying the whole of a score or scores formed in said rupture disk.

9. Apparatus according to any one of claims 1 to 4, wherein said rupture disk is formed as an integral member which includes two portions of different thickness, the thicker portion being comprised of a disk of substantially uniform thickness and the portion of lesser thickness is formed by one or more recesses formed in said disk and including one or more scores formed therein.

10. A rupture disk according to any preceding claim, wherein the disk includes an annular flange for clamping between support members and a central concave-convex domed portion in which said score or scores are formed.

11. A rupture disk substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 3 of the accompanying drawings.

12. A rupture disk according to claim 11, modified substantially as hereinbefore described with reference to and as illustrated in Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9, Figures 10 and 11, Figures 12 and 13 or Figures 14 and 15 of the accompanying drawings.