WO1993013346A1

WO1993013346A1 - Flange

Info

Publication number: WO1993013346A1
Application number: PCT/SE1992/000875
Authority: WO
Inventors: Christer Bengtsson
Original assignee: Applitech Sparfläns Ab
Priority date: 1991-12-20
Filing date: 1992-12-18
Publication date: 1993-07-08
Also published as: SE9103782D0; AU3270393A; MX9207348A; SE469000B; SE9103782L

Abstract

The invention relates to a universal flange comprising a body (100) having a sealing surface (101) in which there are formed a first set of bolt holes, distributed along a first hole circle, to permit connection with a counter flange having bolt holes corresponding to the first set of bolt holes, and at least a further set of bolt holes distributed along a second hole circle, to permit connection with another counter flange having bolt holes corresponding to the further set of bolt holes. The first and the second hole circles have different diameters, and at least the bolt holes along the smallest hole circle are formed as non-through holes and provided with inside threads for receiving studs.

Description

FLANGE

The present invention relates to a flange comprising a body and bolt holes formed therein to permit attachment of the flange to a counter flange by means of a bolt con¬ nection. The invention is intended especially for non-per¬ manent flange connections.

The flange according to the invention can be design¬ ed both as a coupling flange and as a blind flange, i.e. as a flange with or without a passage for a flowing medium. The following discussion regarding prior art technique and the problems and drawbacks thereof, as well as how to solve these problems by means of the invention thus applies both to coupling flanges and to blind flanges.

Flanges for non-permanent mounting are used in a large number of fields, such as on petrol trucks for bunkering boats and for emptying tanks and piping sys¬ tems; in fire service for e.g. emptying petrol trucks in case of an accident; in industry for cleaning tanks and for hydrostatic tests and temporary shut-offs; in oil ports for bunkering ships; on oil tankers for bunkering in different countries (with varying counter flanges) etc. In general, a flange connection may be considered to comprise a coupling flange (or blind flange) and a counter flange as well as a number of bolts. To illustrate prior art and the features of the invention, it is assumed below that the counter flange is the flange to be connected with the flange according to the present invention.

An exceedingly large number of special-type flanges exists today in the world, on the one hand variants dif¬ fering between different countries and, on the other hand, variants within the same country for e.g. different com- pressive loads and connections. Table I in Fig. 9 in the accompanying drawings illustrates examples of a number of existing special-type flanges, the dimensions A, B and C indicated in the Table corresponding to the marks in Fig. 4A which shows a PN 40 flange with eight bolt holes.

This large number of different types of flange neces¬ sitates access to and handling of a correspondingly large number of coupling flanges or blind flanges to render it possible to connect a specific type of flange on site. Thus, a petrol truck or a fire-brigade motor-car must car¬ ry a large number of special-type flanges, one for every conceivable type of counter flange, which is both expen- sive and cumbersome.

It often happens that the correct type of flange, corresponding to a certain counter flange, is not avail¬ able. This problem is sometimes temporarily solved by clamping the two flanges together by means of cramps, which involves a great risk of accident.

EP-A1-0 072 372 discloses a flange for connecting heated or cooled pipings. An illustrated embodiment of this flange comprises two concentric hole circles having a large and a small diameter, respectively. The outer hole circle is formed with eight through bolt holes, and on the inner hole circle there are four through bolt holes. When attaching this prior art flange, use is made of all the bolt holes in the flange. The reason why this flange has double hole circles with bolt holes is that it is special- ly designed for connection with heated or cooled pipes.

In the technical field described above, there is thus a great problem which is unsolved up to now. The object of the invention is to solve this problem.

More particularly, the object of the invention is to eliminate the need of a large number of different special- type flanges with different hole circles.

A special object of the invention is to provide a universal flange which can replace a large number of spe¬ cial-type flanges. A further object of the invention is to provide such a universal flange which is inexpensive and simple to manufacture, especially a universal flange which has as few bolt holes as possible, but which still covers a great number of different hole circles.

To achieve these and other objects, there is provided a flange comprising a body having a main.surface in which a first set of bolt holes is formed, distributed along a first hole circle, to permit connnection with a counter flange which is adapted to be attached to said main sur¬ face and which has bolt holes corresponding to said first set of bolt holes, the flange being characterised in that said main surface of the body is formed with at least one further set of bolt holes, distributed along a second hole circle, to permit connection with another counter flange which is adapted to be attached to said main surface and which has bolt holes corresponding to said further set of bolt holes, the first and the second hole circle having different diameters, and that at least the bolt holes along the smallest of said hole circles are formed as non- through holes and provided with inside threads for receiv¬ ing studs. Preferably, all bolt holes of the flange are non- through holes and provided with inside threads for receiv¬ ing studs.

Preferably, the flange has in said main surface more than one further set of bolt holes, distributed along hole circles having different diameters.

Preferably, the bolt holes along each hole circle are four in number, distributed at an angle of 90° to each other.

When the flange according to the invention (below called the universal flange) is to be connected with a counter flange, bolts are inserted in the bolt holes of the universal flange which fit the hole circle of the counter flange in question. In this case, the remaining bolt holes of the universal flange are not used. If, as is preferred, all bolt holes of the universal flange are formed as non-through holes having inside threads, said bolts are studs which thus are screwed into the bolt holes of the universal flange which fit the hole circle of the counter flange in question. The opposite ends of the studs, which are also threaded, are passed through traditional, unthreaded through bolt holes of the counter flange, whereupon nuts are screwed onto the studs which then project from the side of the counter flange facing away from the universal flange.

A characteristic feature of the invention is that at least the innermost bolt holes of the universal flange are non-through holes. Consequently, the universal flange can be designed for use with hole circles of highly varying diameters. For example, in its simplest embodiment (two hole circles only) the universal flange has a relatively small hole circle and a relatively large hole circle. If such a universal flange should be connected with a counter flange whose hole circle corresponds to the large hole circle of the universal flange, bolts (studs) are thus inserted in the bolt holes of the large hole circle only, whereas the non-through bolt holes of the small hole cir- cle are left empty. Since these interior bolt holes are non-through, no leakage can arise through them, which would be possible if they were through. A counter flange normally has a centrally positioned passage or connection opening which usually is wider the larger the hole circle of the counter flange. When the universal flange is con¬ nected with a counter flange which has a relatively large passage, it may therefore happen that not used, interior bolt holes of the universal flange are covered by (i.e. are open to) the passage of the counter flange. This would result in leakage through the interior bolt holes if they were through.

According to a particularly preferred embodiment of the invention, one or more of the bolt holes of the uni¬ versal flange are common to two or more hole circles. Hole circles having a common bolt hole will thus be eccentric in relation to each other. An advantage of having common bolt holes is that fewer holes are required, which means that the universal flange will on the one hand be easier and cheaper to manufacture and, on the other hand, be easier to use since fewer holes have to be considered.

The flange according to the invention can also have hole circles which do not have common holes but still are eccentric in relation to each other.

A general advantage of using eccentric hole circles, independently of whether they have common bolt holes or not, is that a minimum distance between the bolt holes of e.g. > 6-7 mm can be maintained. Moreover, by arranging hole circles to be eccentric in relation to each other, a sort of synergistic effect can be attained, viz. the holes of the Universal flange can be so distributed that also for deviating flange types, for example flanges hav- ing a deviating number of holes, such as flanges with five holes, it will most probably be possible to find in the hole pattern a fitting set of bolt holes which belong to several different, eccentric hole circles of the universal flange. According to a preferred embodiment of the invention, the diameter of the bolt holes, and consequently the dia¬ meter of the studs, is relatively small as compared to the bolt holes of the counter flanges with which trie universal flange is intended to be connected. For example, the bolt holes/studs may have a diameter in the order to 10-14 mm for counter flanges with bolt hole diameters from 14 mm and upwards, which results in a certain clearance between the bolt holes of the counter flange and the studs loosely received therein. This makes it possible to connect the universal flange not only with counter flanges with such hole circles as are to be found among the hole circles of the universal flange, but also with counter flanges having deviating hole circles. When the universal flange accord¬ ing to this embodiment is connected with such a counter flange with a deviating hole circle, the studs will thus be eccentrically positioned in the bolt holes of the coun¬ ter flange. According to this embodiment of the invention, use is preferably made of relatively large nuts, alter¬ natively large washers, to permit clamping of counter flanges whose bolt holes have a diameter which is rela¬ tively much greater than the diameter of the studs. If the universal flange according to the invention is designed as a coupling flange (i.e. has a passage inside its hole circles), an eccentricity, if any, between a hole circle of the universal flange and the passage thereof is, in a preferred embodiment, so restricted that the passage of the universal flange is positioned completely inside a passage of a counter flange, which corresponds to the bolt circle in question. This prevents a throttling effect from arising in the transition between the two passages.

The inside threads in the bolt holes of the universal flange may be formed directly in the flange body or be designed as insert threads.

The above-mentioned and other features of the inven¬ tion are stated in the claims.

An exemplifying, non-restrictive embodiment of the invention and the use thereof will now be described with reference to the accompanying drawings.

Fig. 1 is a perspective view of an embodiment of a universal flange according to the invention, designed as a coupling flange, i.e. formed with a passage. Fig. 2 is a perspective view of the universal flange in Fig. 1, seen from the other side of the flange.

Fig. 3 is a top plan view of the universal flange in Fig. 1, seen from the apertured sealing surface of the flange. Fig. 4A is a top plan view of a counter flange with eight holes and should be viewed in combination with the above-mentioned Table I and Fig. 4B.

Fig. 4B which is to be viewed in combination with Fig. 4A is useful for explaining how the counter flange in Fig. 4A can be connected to the universal flange in Figs 1-3. Fig. 5 which is to be viewed in combination with Table II in Fig. 10 is useful for explaining the position¬ ing of the bolt holes belonging to the four innermost hole circles of the universal flange in Figs 1-3. Fig. 6 which is also to be viewed in combination with Table II in Fig. 10 is useful for explaining how some of the bolt holes of the universal flange in Figs 1-3 are common to two hole circles.

Fig. 7 which is also to be viewed in combination with Table II in Fig. 10 is useful for explaining how a counter flange having a "deviating" hole circle can be connected to the universal flange in Figs 1-3.

Fig. 8 is a schematic longitudinal section of a flange connection or mounting, comprising a universal flange according to the invention, and a counter flange. Fig. 9 shows Table I of a number of different, known flange types.

Fig. 10 shows Table II for use in combination with the universal flange in Figs 1-3. The universal flange illustrated in Figs 1-3 is a 'circular, disc-shaped body 100 made of e.g. aluminium or stainless steel. In the shown embodiment, the body 100 has a diameter of about 260 mm and a thickness of about 25 mm. The body 100 is formed with 36 threaded non-through bolt holes which are numbered 1-36 and which are open to a sealing surface 101 of the flange 100 and a threaded, through passage 102 positioned inside the bolt holes 1-36. In the illustrated embodiment, the bolt holes 1-36 are about 15 mm deep, and thus about 10 mm of the material of the body 100 remains between the bottoms of the bolt holes 1-36 and the opposite side 103 of the flange 100.

In practice, the bolt holes 1-36 can be identified either by providing the flange body 100 with marks adja¬ cent each hole, for example engraved on the surface 101, or by using a separate hole gauge which, when used, can be placed on the surface 101. The positions of the bolt holes 1-36 relative to each other and to the flange body 100, and the passage 102 of the flange are to be seen in the top plan view in Fig. 3. Fig. 3 also illustrates that the passage 102 is eccentri- cally positioned relative to the outer circumference of the flange body 100. The perspective view in Fig. 2 also clearly illustrates that all the bolt holes 1-36 are non- through in this embodiment of the invention.

Reference is now made to Figs 4A and 4B which show on the one hand (Fig. 4A) a counter flange 300 of flange type No. 30 in Table I (i.e. a PN 40 counter flange hav¬ ing a hole circle diameter (A) of 220 mm, a bolt hole diameter (B) of 26 mm and a connection diameter (C) of 125 mm, and having eight uniformly distributed bolt holes) and, on the other hand, (Fig. 4B) how this counter flange in Fig. 4A can be connected with the universal flange 100 in Figs 1-3.

The eight 26 mm bolt holes of the PN 40 counter flange are numbered 301-308 in Fig. 4A, while its central 125 mm connection opening is designated 310. Moreover, the two diameters of the 220 mm hole circle, which pass through the bolt holes 302/306 and 304/308, respectively, are in Fig. 4A designated Dl and D2.

Fig. 4B is essentially made by superposing on the hole pattern in Fig. 3 the four bolt holes 302, 304, 306 and 308, the connection opening 310 and the two diameters Dl and D2 from Fig. 4A. As is evident from Fig. 4B, the bolt holes 4, 10, 12 and 18 of the universal flange are distributed at an angle of 90° to each other along a hole circle fitting the holes 308, 302, 304 and 306, respec¬ tively, of the counter flange 300. By (i) screwing in one end of four studs (cf. reference numeral 400 in Fig. 8) into each of the bolt holes 4, 10, 12, 18, (2) inserting these four studs into the bolt holes 308, 302, 304 and 306, respectively, of the PN 40 counter flange, and (3) subsequently screwing nuts (cf. reference numeral 500 in Fig. 8) to the studs on the other side of the counter flange, these two flanges can thus be connected with each other.

In Fig. 4B there are three items to be noted. First, the point of intersection P of the diameters Dl and D2 is offset a distance Δ relative to the centre of the passage 102 of the universal flange 100. Secondly, the passage 102 of the universal flange 100 is positioned entirely inside the considerably larger passage 310, with a diameter of 125 mm, of the counter flange 300. Thirdly, a plurality of the non-used holes of the counter flange 100, more pre¬ cisely the twelve bolt holes 6-8, 21, 22, 24, 25, 28, 29, 32, 33 and 36, are positioned entirely or partly inside the connection opening 400 of the counter flange 300. How¬ ever, no leakage arises through these twelve bolt holes, since they are non-through.

The positioning of the bolt holes 1-36 of the univer¬ sal flange 100 will now be explained in more detail by means of Table II in Fig. 10 in combination with Figs 5 and 6. The bolt holes 1-36 are distributed along hole cir- cles with the diameters 110 mm, 125 mm, ..., 220 mm stated in the left column of Table II, the bolt holes included in the respective hole circle being stated in the right column of Table II. The two lowermost lines in Table II indicate that the same bolt holes can be used for more than one hole circle.

In Fig. 5 the diameters between the bolt holes are drawn for the four smallest hole circles in Table II, i.e. for hole circles with the respective diameters 110 mm (full line), 125 mm (dashed line), 135 mm (dash-dotted line) and 145 mm (dotted line). These four hole circles are, as shown in Fig. 5, centred relative to the passage 102 and have no common bolt holes.

In Fig. 6 the diameters between the bolt holes are drawn for the hole circles 150 mm (full line), 180 mm (dashed line) and 200 mm (dotted line). The hole circles 150 and 180 are, as is evident from Fig. 6, eccentric relative to the passage 102. It is also apparent from Fig. 6 (and also from Table II) that the hole circles 150 and 180 have a common bolt hole, viz. hole No. 8. The hole circle 180 has, in turn, a further bolt hole in common with the hole circle 200, viz. hole No. 19. Similarly, the remaining hole circles in Table II can be drawn. Thus, e.g. bolt hole No. 2 is common to the hole circles 160, 180 and 190, and bolt hole No. 9 is common to the hole circles 190 and 200.

When the universal flange is to be used in actual practice, the following procedure may be used. First, the hole circle of the counter flange is measured to be, say, 160 mm. Then one looks into Table II for the measured hole circle in order to identify which four bolt holes to use for this counter flange, in this case the bolt holes 2, 7, 13 and 18. Subsequently, these four holes are identified on the actual flange, for example by means of numbers engraved thereon according to Fig. 3. A stud is then screwed into each identified hole, whereupon the flange connection is completed by means of nuts. In practice, it is just necessary to locate one of the identified holes in the flange and screw a stud into this single hole. This single stud can then be inserted into the corresponding bolt hole of the counter flange, whereupon the other bolt holes of the universal flange are located by means of the other bolt holes of the coun¬ ter flange.

As described above, the universal flange is connect- ible to such hole circles as are not shown in Table II, if the bolt holes of the universal flange and the asso- ciated studs have a limited diameter. To illustrate this possibility, it is now assumed that the counter flange to which the universal flange is to be connected is a type 2 flange in Table I, i.e. Ib/Sq 150 with a hole circle (A) of 120.6 mm, a bolt hole diameter (B) of 19 mm and four bolt holes. This 120.6 mm hole circle is not shown in

Table II. The hole circle in Table II which is closest to 120.6, in this case the 125 mm hole circle, is selected. Thus, bolt holes 25-28 are to be used in this case. As is evident from Fig. 7, which illustrates this case, the four bolt holes of the counter flange 300 will be eccen¬ tric relative to the bolt holes 25-28, however not more eccentric than to allow the studs to be inserted through the bolt holes of the counter flange. Correspondingly, all other "deviating" hole circles can be managed by the universal flange.

Different alternatives are conceivable for the seal- ing between the universal flange and the counter flange. A first alternative is to use a seal which is permanently mounted on the counter flange. A second alternative is to arrange a seal having a hole pattern identical with that of the universal flange. A third alternative is to use separate special-type seals, one for each hole circle.

Fig. 8 is a schematic view of a universal flange 100 connected with a counter flange 300 by means of studs 500 and nuts 800. Fig. 8 illustrates a case where the passage 102 of the universal flange 100 is eccentrically position- ed relative to the passage 310 of the counter flange 300. The non-used bolt holes of the universal flange 100 are not shown in Fig. 8. In accordance with the above descrip¬ tion, it is however understood that the universal flange can especially have bolt holes radially inside the shown bolt holes, leakage through such radially inwardly posi¬ tioned bolt holes being prevented since they are non- through.

The invention has been described above by means of a preferred embodiment, but it is understood that several modifications can be made, without deviating from the scope of the invention, as defined in the accompanying claims.

Thus, some of the bolt holes of the flange can be through. Other hole circles than those in Table II can of course be used. Moreover, as indicated above, the flange can be designed as a blind flange with no passage.

Claims

1. Flange comprising a body (100) with a main sur- face (101) in which a first set of bolt holes is formed, distributed along a first hole circle (21-24), to permit connection with a counter flange which is adapted to be attached to said main surface (101) and which has bolt holes corresponding to said first set of bolt holes, c h a r a c t e r i s e d in that said main surface

(101) of the body (100) is formed with at least one fur¬ ther set of bolt holes, distributed along a second hole circle (2, 8, 16, 19), to permit connection with another counter flange which is adapted to be attached to said main surface (101) and which has bolt holes corresponding to said further set of bolt holes, the first and the second hole circle having different diameters, and that at least the bolt holes along the smallest of said hole circles are formed as non-through holes and provided with inside threads for receiving studs.

2. Flange as claimed in claim 1, c h a r a c t e r ¬ i s e d in that all bolt holes (1-36) of the flange are non-through and provided with inside threads for receiving studs.

3. Flange as claimed in claim 1 or 2, c h a r a c ¬ t e r i s e d in that said main surface (101) of the body (100) is formed with more than one further set of bolt holes, distributed along hole circles of different diameters.

4. Flange as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that the bolt holes of each hole circle are four in number and distri¬ buted at an angle of 90° to each other.

5. Flange as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that one or more of the hole circles are eccentric in relation to other hole circles.

6. Flange as claimed in claim 5, c h a r a c t e r ¬ i s e d in that one or more of the bolt holes are common to two or more hole circles.

7. Flange as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that the diameter of the bolt holes is smaller than that of the bolt holes of the counter flanges with which the flange is to be connected, thereby forming a clearance between the bolts and the bolt holes of the counter flange.

8. Flange as claimed in claim 8, c h a r a c t e r ¬ i s e d in that the diameter of the bolt holes is in the order of 10-14 mm.

9. Flange as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that the flange is designed as a coupling flange having a through passage (102).

10. Flange as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that said inside threads in the bolt holes (1-36) of said flange are formed directly in the body (100) of the flange.