Lifting device for use in fitting and/or removing heavy flange bolts and method for fitting such a flange bolt

Abstract

 A lifting device (8) for use in fitting and/or removing heavy threaded flange bolts (5) in the case of a flange assembly consisting of two flanges (1, 2) lying opposite each other and provided with bolt holes (4), and having a substantially vertical axis, comprises a jack (9) with a first pressure plate (13) and a second pressure plate (14) which is movable relative to the first pressure plate, and a lead screw (11, 12) for moving the first part and the second part relative to each other, a first supporting part (16) connected to the first part (13) and extending in the transverse direction relative to the axis of the jack (9), and a second supporting part (17) connected to the second part (14) and extending in the transverse direction relative to the axis of the jack (9).

Description

[0001] The invention relates to a lifting device for use in fitting and/or removing heavy threaded flange bolts in the case of a flange assembly consisting of two flanges lying opposite each other and provided with bolt holes, and having a substantially vertical axis.

[0002] Flanged joints are often used in industrial plants, such as oil refineries, power stations, chemical factories and the like in order to connect ends of pipes to each other. In certain cases the flanges and the corresponding flange bolts can be of a very large and heavy design. Fitting and removing the heavy flange bolts, which can weigh up to 70 - 80 kg, is currently still often performed manually, since the use of a crane is expensive and in many cases is even not possible because there is insufficient hoisting space above the threaded bolt to be fitted or removed.

[0003] Manually fitting a heavy threaded flange bolt in the case of a flange assembly consisting of two flanges lying opposite each other and provided with bolt holes, and having a substantially vertical axis, is performed as follows. A first fitter inserts the flange bolt from below into the corresponding bolt hole, generally from a crouching position or down on his knees. He moves the flange bolt further upwards into the bolt hole with both hands until the top end of the bolt is projecting with a number of leads above the top flange, so that a second fitter can screw a nut onto the top end of the bolt. Sometimes the nut does not screw smoothly onto the flange bolt, so that the latter tends to turn with the nut. The first fitter then has to apply even more effort to hold the bolt. In the case of very heavy flange bolts a lever beam is also sometimes used to move the flange bolt upwards in the bolt hole.

[0004] Manually fitting and removing heavy flange bolts, which can be present in a relatively large number (up to 24 or more) in one flanged joint, means a heavy load being placed upon the fitters, and can also lead to unsafe situations.

[0005] The object of the invention is to make it easier to fit and/or remove heavy threaded flange bolts in the case of a flange assembly consisting of two flanges lying opposite each other and provided with bolt holes, and having a substantially vertical axis.

[0006] This object is achieved by a lifting device according to claim 1 and a method according to claim 7.

[0007] The effort that has to be expended by the fitters is considerably reduced by making use of the lifting device according to the invention and using the method according to the invention. In certain cases only one fitter is now needed to fit or remove a flange bolt. Furthermore, a flange bolt can be fitted or removed more quickly, and the chance of dangerous situations arising is considerably reduced.

[0008] Preferred embodiments of the lifting device and method according to the invention are described in the dependent claims.

[0009] The invention will be explained in the description of an exemplary embodiment that follows with reference to the drawing, in which:

Fig. 1 shows a view in cross-section (Fig. 1a) and a view in perspective and in cross-section (Fig. 1b) of a flange assembly with a flange bolt and lifting device according to the invention.

Figs. 2 to 8 show the successive steps of fitting a heavy flange bolt with the aid of the lifting device according to the invention.

[0010] Fig. 1a shows in a view in cross-section, and Fig. 1b shows in a view in perspective and in cross-section, a flange assembly with a flange bolt and a lifting device according to the invention, in which the axis of the flange assembly is substantially vertical. The flange assembly consists of two flanges 1 and 2 lying opposite each other and one on top of the other. The bottom flange 1 is connected to a pipe end 3 by means of a welded seam (not shown). Said welded seam is made in a V-shaped recess formed by bevelled edges 3a and 1a respectively on the pipe end 3 and on a connecting part 1b of the bottom flange 1. The top flange 2 is designed as a closing flange. The top flange 2 could, however, also be designed in the same way as the bottom flange 1 and connected to a pipe end, in which case the flange assembly connects two pipe ends to each other. The flanges 1 and 2 are provided with bolt holes 4 lying opposite each other. The flanges are connected to each other by means of flange bolts 5 projecting through the bolt holes 4, only one of which flange bolts is shown in Figs. 1a and 1b. The number of bolts connecting the two flanges 1 and 2 to each other can be relatively large, for example 24 or more. Each of the flange bolts 5 is provided with a first nut 6 and a second nut 7. However, it is also possible for a flange bolt 5 to be provided with a fixed head instead of a first nut 6 on the end concerned.

[0011] The invention relates in particular to fitting and/or removing heavy flange bolts 5, which can have a weight of up to 70 - 80 kg, in the situation in which the axis of the flange assembly is substantially vertical.

[0012] Figs. 1a and 1b further show a lifting device indicated in general by 8, which lifting device is used for fitting and/or removing such heavy flange bolts 5.

[0013] The embodiment of the lifting device 8 according to the invention shown in Figs. 1a and 1b comprises a jack 9 in the form of a screw jack. The jack 9 comprises an elongate housing 10 and a lead screw 11 which is rotatable in said housing, and outside the housing is provided with a drive nut 12. The lead screw 11 can be turned with the aid of an auxiliary tool that is applied to the drive nut 12. This auxiliary tool can be a key or a crank by means of which the lead screw 11 is turned manually, or it can be an electric or pneumatic rotating tool. The jack 9 further comprises a first pressure plate 13 which is connected to the housing 10 and a second pressure plate 14 which is movable relative to said first pressure plate. The second pressure plate 14 can be moved relative to the first pressure plate 13 by means of the lead screw 11. The jack 9 in the exemplary embodiment shown is a commercially available jack which is used in the automobile industry for fitting McPherson springs. However, the jack can also be another type of jack.

[0014] The lifting device 8 further comprises a first supporting part 16, which is connected to the first pressure plate 13 and extends in the transverse direction relative to the axis of the jack 9, and a second pressure part 17, which is connected to the second pressure plate 14 and extends in the transverse direction relative to the axis of the jack. The first supporting part 16 is preferably connected in a detachable manner by way of a first connecting part 18 to the first pressure plate 13, and the second supporting part 17 is preferably connected in a detachable manner by means of a second connecting part 19 to the second pressure plate 14. The connecting parts 18 and 19 are fixed on the pressure plates 13 and 14 by means of bolts 20. The first supporting part 16 and the first connecting part 18 together form a substantially L-shaped part. The second supporting part 17 and the second connecting part 19 likewise together form a substantially L-shaped part. The supporting parts 16 and 17 are preferably shaped like a fork. The first supporting part 16 is further provided with a plastic disc 21. Said plastic disc is formed so as to be complementary to the fork shape of the supporting part 16 in such a way that it can be pushed to fit in and around the fork-shaped supporting part 16, and is subsequently also removable again, so that it can be fitted as desired on and removed from the desired supporting part 16.

[0015] The second supporting part 17 is designed for placing between the two flanges 1 and 2 during use of the lifting device for fitting and/or removing heavy flange bolts, and the first supporting part 16 with the plastic disc 21 is designed for placing under a flange bolt 5 to be fitted and for supporting the latter.

[0016] The lengths in the vertical direction of the connecting parts 18 and 19 are the same in Fig. 1. Depending on the dimensions of the flange bolt 5 and the flanges 1 and 2, the connecting parts 18, 19 of the L-shaped parts 16, 18 and 17, 19 respectively can be longer or shorter, or can be of different lengths from each other.

[0017] In order to provide a lifting device 8 which is flexible in use in different situations for different dimensions of the flange bolt 5 and of the flanges 1 and 2 (in particular different flange thicknesses), a tool kit can be provided, consisting of a jack 9 and several L-shaped parts 16, 18 and 17, 19 respectively with different dimensions. For example, it is possible to provide a tool kit consisting of a jack 9 and four accompanying L-shaped attachments, two of which have a short connecting part 18, 19 and can be used as the L-shaped parts 16, 18 and 17, 19 respectively with a short connecting part 18, 19, and the other two L-shaped attachments of which have a long connecting part 18, 19 and can be used as the L-shaped parts 16, 18 and 17, 19 respectively with a long connecting part 18.

[0018] In a certain situation two suitable L-shaped attachments can then be selected and fitted by means of bolts 20 on the first pressure plate 13 and on the second pressure plate 14 of the jack 9, in order to form a complete lifting device 8 which is suitable in that situation. In this way different lifting devices 8 can be made with this tool kit by combining a jack 8 with two short L-shaped attachments or with one short L-shaped attachment and one long L-shaped attachment, or with two long L-shaped attachments, which lifting devices are suitable for fitting or removing a flange assembly with not so thick, moderately thick or rather thick flanges 1, 2 respectively with the corresponding shorter or longer flange bolts 5.

[0019] The L-shaped attachments forming the L-shaped parts 16, 18 and 17, 19 respectively can be made of steel. The L-shaped attachments form a considerable part of the weight of the lifting device 8 and certainly also form a considerable part of the weight of the tool kit, as described above. The L-shaped attachments can advantageously be made of aluminium, so that a relatively light lifting device 8 or tool kit is produced.

[0020] The various steps in the process for fitting a heavy threaded flange bolt in the case of a flange assembly consisting of two flanges lying opposite each other and provided with bolt holes, and having a substantially vertical axis, with the aid of the lifting device according to the invention are shown in Figures 2 to 8, in the "a" figures a part of the flange assembly with flange bolt and lifting device being shown in side view, while in the "b" figures a part of a flange assembly with flange bolt and lifting device is shown in a perspective view from the top side and in cross-section.

[0021] Figs. 2a and 2b show the situation in which a closing flange 2 (top flange) is placed on a flange 1 (bottom flange) connected to a vertically disposed pipe end 3. As mentioned earlier, the flange 2 could also be connected to a pipe end (not shown) in the same way as the flange 1. The bolt holes 4 in the flanges 1 and 2 lie opposite each other.

[0022] Figs 3a and 3b further show a flange bolt 5 to be fitted, having a first nut 6 screwed onto it. Instead of the nut 6, the flange bolt 5 could also be provided with a fixed head on the end concerned. The flange bolt 5 is inserted manually by a fitter from below into the corresponding bolt hole 4 in the bottom flange 1.

[0023] As shown in Figs. 4a and 4b, the lifting device 8 according to the invention is then placed. The supporting parts 16 and 17 are moved apart here. The second supporting part 17 is placed between the flanges 1 and 2, and the first supporting part 16 with the plastic disc 21 is placed under the flange bolt 5 to be fitted. The flange bolt 5 is now supported by the lifting device 8, so that the fitter who initially inserted the flange bolt 5 into the corresponding bolt hole has his hands free. The lifting device 8 can be fitted by the fitter who initially inserted the flange bolt 5 into the corresponding bolt hole 4, or by a second fitter. Turning the lead screw 11 of the jack 9 by means of an auxiliary tool (not shown) placed on the drive nut 12 of the lead screw causes the two supporting parts 16 and 17 to move towards each other, so that the flange bolt 5 is moved upwards into the corresponding bolt hole (arrow 22 in Figs. 4a, 4b and Figs. 5a, 5b).

[0024] In Figs. 5a and 5b the flange bolt 5 is moved further into the corresponding bolt hole and the second nut 7 to be screwed onto the flange bolt 5 on the top side of the top flange 2 is also shown. The flange bolt 5 is moved further upwards by turning the lead screw 11 of the jack 9 (arrow 23 in Fig. 5b). In the course of this the flange bolt 5 moves through between the legs of the fork-shaped second supporting part 17.

[0025] Figs. 6a and 6b show the situation in which the flange bolt 5 has moved so far up that one or two leads of the flange bolt 5 extend above the top flange 2, as indicated at 24. The two supporting parts 16 and 17 have now moved so far towards each other that the two pressure plates 13 and 14 of the jack 9 are lying close to each other or resting against each other. The second nut 7 can now be screwed onto the flange bolt 5. The flange bolt 5 is supported on the plastic disc 21 provided in the fork-shaped supporting part 16 and consequently undergoes a friction force which offers resistance to slipping and turning, so that the flange bolt 5 is prevented from turning along with the nut 7 when the latter is being screwed onto it. The situation shown in Figs. 6a and 6b corresponds substantially to the situation shown in Figs. 1a and 1b.

[0026] The second nut 7 is screwed further onto the flange bolt 5, so that the flange bolt moves further upwards and comes away from the first supporting part 16 with plastic disc 21. The lifting device 8 can now be removed, as shown in Figs. 7a and 7b.

[0027] Figs. 8a and 8b show the situation in which the flange bolt 5 with nuts 6 and 7 is fitted in the flange assembly.

[0028] The operations described above must be carried out for each of the flange bolts 5 to be fitted in the bolt holes 4 of the flange assembly. The number of bolt holes 4 can be relatively large and can be up to 24 or more.

[0029] For the removal of a flange bolt 5 the operations described above are in principle performed in reverse order.

[0030] The invention is not restricted to the embodiments of the lifting device and the method according to the invention described above. The lifting device can be of a different design and, for example, comprise a different type of jack. The supporting parts 16, 17 could also be designed in such a way that they can be connected directly (i.e. without the connecting parts 18, 19) to the pressure plates 13, 14.

Claims

1. Lifting device for use in fitting and/or removing heavy threaded flange bolts in the case of a flange assembly consisting of two flanges lying opposite each other and provided with bolt holes, and having a substantially vertical axis, comprising a jack with a first part and a second part which is movable relative to the first part, and means for moving the first part and the second part relative to each other, a first supporting part connected to the first part and extending in the transverse direction relative to the axis of the jack, and a second supporting part connected to the second part and extending in the transverse direction relative to the axis of the jack.

2. Lifting device according to claim 1, in which the jack is a screw jack with a lead screw extending through the second part, for moving the second part relative to the first part.

3. Lifting device according to claim 1 or 2, in which the supporting parts are detachably connected to the first and second parts respectively of the jack.

4. Lifting device according to one or more of claims 1 - 3, in which each of the two supporting parts is shaped like a fork.

5. Lifting device according to one or more of claims 1 - 4, in which one of the two supporting parts is provided with a plastic disc.

6. Lifting device according to one or more of claims 1 - 5, in which each of the two supporting parts is connected, by means of a connecting part extending substantially parallel to the axis of the jack, to the first and second parts respectively of the jack, in such a way that the supporting part together with the connecting part forms a substantially L-shaped part.

7. Lifting device according to claim 6, in which the L-shaped part is made of aluminium.

8. Assembly comprising a jack with a first part and a second part which is movable relative to the first part, and means for moving the first part and the second part relative to each other, and at least two substantially L-shaped parts which are connected or are to be connected detachably to the first and the second parts and each consist of a supporting part and a connecting part extending substantially transversely to the supporting part, by means of which connecting part the supporting part can be connected or is connected to the first or the second part of the jack.

9. Assembly according to claim 8, in which the jack is a screw jack with a lead screw extending through the second part, for moving the second part relative to the first part.

10. Assembly according to claim 8 or 9, comprising at least three substantially L-shaped parts, in which the dimensions of the L-shaped parts, in particular the lengths of the connecting parts, can be different from each other.

11. Assembly according to one or more of claims 8 - 10, in which each of the supporting parts is shaped like a fork.

12. Assembly according to one or more of claims 8 - 11, in which at least one of the supporting parts is provided with a plastic disc.

13. Assembly according to one or more of claims 8 - 12, in which the L-shaped parts are made of aluminium.

14. Method for fitting a heavy threaded flange bolt in the case of a flange assembly consisting of two flanges lying opposite each other and provided with bolt holes, and having a substantially vertical axis, with the aid of a lifting device according to one of claims 1 - 7, comprising the following steps:

- manually inserting a flange bolt provided with a first nut or head from below into a bolt hole of the bottom flange, the first nut or the head being on the bottom end part of the flange bolt;

- placing the lifting device on the flange assembly in such a way that one of its supporting parts is placed between the two flanges, and the other supporting part is placed under the flange bolt placed in the bolt hole and supports the flange bolt;

- operating the jack in such a way that the supporting part placed under the flange bolt moves upwards with the flange bolt supported on it until the flange bolt is projecting with at least one lead above the top flange.

- screwing a second nut onto the part of the flange bolt projecting above the top flange;

- further tightening the second nut; and

- removing the lifting device from the flange assembly.

15. Method according to claim 14, in which if the jack is in the form of a screw jack with a lead screw, in order to move the flange bolt upwards, the lead screw is turned manually with the aid of a key or crank, or with an electric or pneumatic rotating tool.

Drawing