GB2354036A

GB2354036A - Clamping two pipes against vibration

Info

Publication number: GB2354036A
Application number: GB9921452A
Authority: GB
Inventors: Peter Flockhart; James Stevens Gardner Mcghee; Henry Potter Mcghee
Original assignee: VIBRATION SOLUTIONS Ltd
Current assignee: VIBRATION SOLUTIONS Ltd
Priority date: 1999-09-11
Filing date: 1999-09-11
Publication date: 2001-03-14
Anticipated expiration: 2019-09-11
Also published as: GB9921452D0; GB2354036B

Abstract

An apparatus for clamping two pipes or the like (2,3) together to minimise relative vibration of the pipes. The apparatus comprises a strut (50) and a first (11,12) and second (21,22) pair of semi-circular collar rings which clamp around the pipes (2,3). The first pair of collar rings (11,12) are provided with rotational and translational adjustment mechanisms permitting angular and longitudinal adjustment of the strut (50). The invention provides a clamping apparatus which allows sufficient adjustment so that a single prefabricated apparatus can be used in a range of situations.

Description

2354036 1 1 Pipeline Clamping Apparatus 2 3 This invention relates to an

apparatus for clamping two 4 structural members together to minimise relative 5 vibration of the members. In particular the invention 6 relates to an apparatus for clamping two mutually 7 connected pipes together to minimise the risk of 8 vibration induced fatigue failure at the connection 9 between the pipes. 10 11 Piping systems are used in many industrial applications 12 for the transport of fluids or pourable materials, for 13 example in the oil, chemical, power generation, water, 14 food and beverage industries, and in chemical plants, 15 oil production facilities and factories. Problems can 16 arise through vibrations induced by the flow of the 17 fluid or material through the pipe or by other sources 18 of excitation, particularly if the vibrations are at a 19 frequency close to a natural frequency of a section of 20 pipework. At pipeline connections excessive vibration 21 can result in fatigue failure. Excessive vibration can 22 cause problems with pipe supports, fixings and 23 fittings. This could lead in many instances to 24 structural failure of some elements of the pipework 25 system. Furthermore vibration can cause excessive 2 noise.

2 3 It is known to provide bracing members so as to provide 4 a structural connection between adjacent pipe elements of a pipework system, in order to minimise vibration 6 and relative movement of the pipe elements. This is 7 particularly useful where a small bore attachment is 8 cantilevered from a large bore pipe. Vibration of the 9 system can cause excessive deflection of the small bore attachment and can lead to fatigue failure of the 11 connection. If the movement of the small bore 12 attachment is limited by a bracing member connected at 13 a point remote from the connection, then the stresses 14 at the connection arising from the vibration are is greatly reduced and the risk of fatigue failure is 16 minimised.

17 18 However such bracing members must be specially 19 fabricated to suit the geometry of the pipework, the sizes of the pipe members to be connected, and any 21 interfering elements, such as other pipe members, 22 structural members, valves or other services. This 23 often requires in situ fabrication techniques, such as 24 welding and cutting on site. In remote locations, such as offshore oil platforms, the cost of providing 26 skilled fabricators and fabrication facilities on site 27 can be prohibitive.

28 29 It is an object of the present invention to provide a clamping apparatus for joining two structural members 31 which can be prefabricated off site and assembled on 32 site with some possibility of adjustment without the 33 need for on site fabrication facilities.

34 According to a first aspect of the present invention 36 there is provided a clamping apparatus for joining 3 1 first and second structural members comprising a first 2 clamping means adapted to clamp to the first structural 3 member, a second clamping means adapted to clamp to the 4 second structural member, a strut member having a first 5 end and a second end, 6 wherein the first clamping means is provided with first 7 connection means adapted to connect the first clamping 8 means to the first end of the strut member, 9 wherein the second clamping means is provided with 10 second connection means adapted to connect the second 11 clamping means to the second end of the strut member, 12 wherein the first connection means is provided with 13 translational adjustment means permitting longitudinal 14 linear adjustment of the strut member with respect to is the first clamping means, and 16 wherein the first connection means is provided with 17 rotational adjustment means permitting angular 18 adjustment of the strut member with respect to the 19 first clamping means. 20 21 Preferably the translational adjustment means comprises 22 a fastener which engages with a longitudinally 23 extending slot in the strut member. 24 25 Preferably the rotational adjustment means comprises a 26 swivel plate which is pivotally engages on a pin 27 connected to the first clamping means. Preferably said 28 pin is a threaded shaft. 29 30 Preferably said swivel plate comprises two mutually 31 perpendicular bearing plates. Preferably the first 32 bearing plate is adapted to engage with a bearing 33 surface fixed to the first clamping means. Preferably 34 an aperture is provided in the first bearing plate to 35 engage with the pin provided on the bearing surface of 36 the first clamping means. Preferably the second 4 1 bearing plate is adapted to engage with a bearing 2 surface on the strut member. Preferably an aperture is 3 provided in the second bearing plate to engage with the 4 fastener which engages with the slot in the strut 5 member. 6 7 In one preferred embodiment the second connection means 8 is similar to the first connection means. 9 10 In another preferred embodiment the second connection 11 means comprises a lug fixed to the second clamping 12 means and provided with an aperture for connection by 13 means of a fastener to the strut member. Preferably 14 the lug extends in a plane which is coplanar with a 15 radius extending perpendicular to the longitudinal axis 16 of the second structural member. The plane may extend 17 at an angle of between 200 and 700 to the axis of the 18 second structural member, preferably between 300 and 19 600.

21 Preferably the first and second structural members are 22 pipes. Preferably the first and second clamping means 23 comprise two or more segmental collar members which are 24 connected to each other by means of flange plates.

26 According to a second aspect of the present invention 27 there is provided a set of components for forming a 28 clamping apparatus according to the first aspect, 29 comprising a number of first and second clamping means of different sizes, each adapted to clamp around a 31 structural member of a different size, and a number of 32 strut members of different length.

33 34 The present invention provides a clamping apparatus with a universal design, allowing the apparatus to be 36 fitted to all common small bore pipework configurations 1 found on process pipework systems. The swivel joint 2 arrangement allows fine adjustment in the principle 3 planes for both the angle and length of the strut 4 members. The clamping means are designed for ease of 5 installation and can be fitted using very basic hand 6 tools by a competent person. No on site cutting, 7 welding or other fabrication process is required. 8 9 An embodiment of the invention will now be described, 10 by way of example only, with reference to the 11 accompanying figures, where: 12 13 Fig. 1 is a first view on a clamping apparatus 14 according to the invention fitted to a large bore pipe 15 and a small bore pipe connected to each other at right 16 angles; 17 18 Fig. 2 is a second view on the clamping apparatus of 19 Fig. 1; 20 21 Fig. 3 is a view on a clamping apparatus according to 22 the invention with the pipes to be clamped omitted for 23 clarity; 24 25 Fig. 4 is an enlarged view of the base plate and swivel 26 plate forming the adjustable connection member of the 27 clamping apparatus of Fig. 3; and 28 29 Fig. 5 is a further enlarged view of the base plate and 30 swivel plate forming the adjustable connection member 31 of the clamping apparatus of Fig. 3. 32 33 Referring to Figs. 1 to 5 there is shown a clamping 34 apparatus 1 comprising a primary clamp 10, which forms 35 the first clamping means and is adapted to fit around a 36 primary pipe 2, and a secondary clamp 20, which forms 6 1 the second clamping means and is adapted to fit around 2 a secondary pipe or valve 3. A pair of struts 50 3 connects the primary clamp 10 and the secondary clamp 4 20. 5 6 The primary clamp 10 comprises two semi- circular collar 7 rings 11, 12 which are placed around the pipe 2 then 8 bolted together using bolts 13 passing through 9 connecting flanges 14. Nuts 13a to receive the bolts 10 13 may be welded to the underside of the lower flanges 11 14, or the nuts may be provided separately. The 12 secondary clamp 20 comprises two semi-circular collar 13 rings 21, 22 which are placed around the secondary pipe 14 3 then bolted together using bolts 23 passing through is connecting flanges 24, in the same manner. 16 17 Each collar ring 11, 12 of the primary clamp is 18 provided with a base plate 15, comprising a length of 19 channel section connected to the collar ring 11, 12 by 20 welding. The base plate 15 has a bearing surface 16 21 from which extends a threaded shaft 17 which serves as 22 a locating pin. This may be formed by inserting a bolt 23 through a hole 19 in the bearing surface 16 from 24 underneath the base plate and welding the bolt head 18 25 to the underside of the bearing surface 16, before 26 welding the base plate 15 to the collar ring 11, 12. 27 28 Each base plate 15 has releasably connected to it a 29 swivel plate 30, which comprises a length of angle 30 section having an aperture 31 for receiving a bolt in 31 each face. A first face 32 of the swivel plate 30 32 forms a bearing plate 32 and is placed on the bearing 33 surface 16 of the base plate 15, by passing the 34 aperture 31 over the threaded shaft 17 or locating pin. 35 A nut 33 is then threaded onto the threaded shaft 17 to 36 secure the swivel plate 30 to the base plate 15. The 7 1 angular position of the swivel plate 30 can be adjusted 2 with respect to the base plate 15 before the nut 33 is 3 tightened, since the swivel plate is free to pivot 4 about the pin 17. The second face or bearing plate 34 5 of the swivel plate is bolted to a slot 60 in the strut 6 50, as described below. 7 8 Each collar ring 21, 22 of the secondary clamp is 9 provided with a connecting lug 25 which extends in a 10 plane which is coplanar with a radius of the secondary 11 pipe 3. Typically the plane extends an angle of about 12 450 with the axis of the secondary pipe 3, but in 13 practice this angle may be between 200 and 700 or even 14 outside this range, depending on the restraints on 15 position of the struts 50 resulting from external 16 factors such as interfering pipework, valves and 17 services. The connecting lug 25 is provided with an 18 aperture 26, through which a bolt 27 may be inserted in 19 order to connect the strut 50 to the lug 25, in a 20 manner described below. A nut 28 to receive the bolt 21 27 may be welded to one side of the lug 25, or the nut 22 may be provided separately. 23 24 Each strut 50 comprises an angle section of an 25 appropriate length to suit the site application. The 26 strut 50 is provided with a number of apertures 52 at 27 its second end, so that the strut may be bolted by 28 means of the nut 28 and bolt 27 passing through the 29 aperture 52 to the lug 25 on the secondary clamp. At 30 the first end of the strut 50 there is a slot 60. A 31 bolt 54 passes through the slot 60 and the aperture 31 32 in the second face 34 of the swivel plate 30, and a nut 33 56 is threaded on the bolt 54 to secure the strut 50 to 34 the swivel plate 30. 35 36 If required a bracing member 70, which is provided with 8 1 a bolt hole 72 at one end and a slot 74 at the other 2 end, is bolted to the struts using pre-formed bolt 3 holes 76 in the struts. 4 5 The provision of a slot 60 in the strut 50 allows 6 adjustment in the effective length of the strut in the 7 direction A, so that it is not necessary to fit the 8 clamps 10, 20 in position on the pipes 2, 3 accurately. 9 The presence of additional holes 52 at the first end 10 allows additional adjustment in length if necessary. 11 The provision of a swivel plate 30 to connect the strut 12 50 to the primary clamp 10 allows rotational adjustment 13 about axes B and C, to suit the relative positions of 14 the primary and secondary clamps 10, 20. 15 16 The clamping apparatus is delivered to site in kit 17 form. A number of different sized primary and 18 secondary clamps 10, 20 may be provided, to suit 19 different sizes of pipe 2, 3. Different secondary 20 clamps 20 may have connecting lugs 25 at different 21 angles of skew. 22 23 To install the clamping apparatus, the clamps 10, 20 24 are first secured to each of the two pipes 2, 3 to be 25 braced. The first strut 50 is then secured at its 26 second end by a bolt 27 to the secondary clamp. The 27 first end of the strut 50 is then laid alongside the 28 swivel plate 30 which is loosely connected to the base 29 plate 15 by threaded shaft 17 on which is loosely 30 threaded nut 33. The swivel plate 30 is swivelled 31 about axis C until the second face 34 of the swivel 32 plate is parallel to the face 51 of the strut 50 33 containing the slot 60. If necessary the longitudinal 34 position of the primary clamp 10 on the primary pipe 2 35 may be adjusted. When the swivel plate 30 is aligned 36 with the strut, a bolt 54 is passed through the 9 1 aperture 31 in the second face 34 and the slot 60 in 2 the strut 50, and then a nut 56 is tightened onto the 3 bolt 54. Nut 33 is also tightened, as are any other 4 remaining loose connections. Finally a bracing member 5 70 is secured to the struts 50, if structural 6 considerations make it necessary. 7 8 The clamping apparatus may be supplied in kit form 9 fully painted, and so offers lower costs compared to 10 those associated with the installation and maintenance 11 of prior art support systems. 12 13 Thus the invention provides a clamping apparatus which 14 can be supplied in kit form, and which allows 15 sufficient adjustment in three degrees of freedom, 16 namely translation in axis A, rotation about axis B and 17 rotation about axis C, so that a single prefabricated is apparatus can be used in a range of situations. 19 20 It is to be understood that a primary clamp, including 21 base plate 15 and swivel plate 30, may be provided at 22 both ends of the strut. 23 24 It is to be understood that the invention may use only 25 one strut 60 in each clamping apparatus, or may use 26 more than two struts. The invention is not limited to 27 clamps using semicircular sleeves, but other forms of 28 pipe clamp may be used. The invention is not limited 29 to struts of angle section, but other structural forms 30 may be used, including channel sections, flat bars or 31 box sections. 32 33 These and other modifications and improvements can be 34 incorporated without departing from the scope of the 35 invention.

36 /u/mur/specs24/p24585-

Claims

1 CLAIMS

2 3 1. A clamping apparatus for joining first and second 4 structural members comprising:

a first clamping means adapted to clamp to 6 the first structural member, 7 a second clamping means adapted to clamp to 8 the second structural member, and 9 a strut member having a first end and a second end, 11 wherein the first clamping means is provided 12 with first connection means adapted to connect the 13 first clamping means to the first end of the strut 14 member, wherein the second clamping means is provided 16 with second connection means adapted to connect 17 the second clamping means to the second end of the 18 strut member, 19 wherein the first connection means is provided with translational adjustment means 21 permitting longitudinal linear adjustment of the 22 strut member with respect to the first clamping 23 means, and 24 wherein the first connection means is provided with rotational adjustment means 26 permitting angular adjustment of the strut member 27 with respect to the first clamping means.

28 29

2. An apparatus as claimed in claim 1 wherein the translational adjustment means comprises a 31 fastener which engages with a longitudinally 32 extending slot in the strut member.

33 34

3. An apparatus as claimed in any preceding claim wherein the rotational adjustment means comprises 36 a swivel plate which is pivotally engages on a pin 11 connected to the first clamping means.

2 3

4. An apparatus as claimed in claim 3 wherein said 4 swivel plate comprises two mutually perpendicular bearing plates.

6 7

5. An apparatus as claimed in claim 4 wherein the 8 first bearing plate is adapted to engage with a 9 bearing surface fixed to the first clamping means.

11

6. An apparatus as claimed in claim 5 wherein an 12 aperture is provided in the first bearing plate to 13 engage with the pin provided on the bearing 14 surface of the first clamping means.

is 16

7. An apparatus as claimed in any of claims 4 to 6 17 wherein the second bearing plate is adapted to 18 engage with a bearing surface on the strut member.

19

8. An apparatus as claimed in claim 7 wherein an 21 aperture is provided in the second bearing plate 22 to engage with the fastener which engages with the 23 slot in the strut member.

24

9. An apparatus as claimed in any preceding claim 26 wherein the second connection means is provided 27 with translational adjustment means permitting 28 longitudinal linear adjustment of the strut member 29 with respect to the second clamping means, and wherein the second connection means is provided 31 with rotational adjustment means permitting 32 angular adjustment of the strut member with 33 respect to the second clamping means.

34

10. An apparatus as claimed in any of claims 1 to 8 36 wherein the second connection means comprises a 12 1 lug fixed to the second clamping means and 2 provided with an aperture for connection by means 3 of a fastener to the strut member.

4

11. An apparatus as claimed in claim 10 wherein the 6 lug extends in a plane which is coplanar with a 7 radius extending perpendicular to the longitudinal 8 axis of the second structural member.

9

12. An apparatus as claimed in claim 11 wherein the 11 lug extends in a plane at an angle of between 200 12 and 700 to the axis of the second structural 13 member.

14

13. An apparatus as claimed in any preceding claim 16 wherein the first and second structural members 17 are pipes.

18 19

14. An apparatus as claimed in any preceding claim wherein the first and second clamping means 21 comprise two or more segmental collar members 22 which are connected to each other by means of 23 flange plates.

24

15. A set of components for assembling an apparatus as 26 claimed in any preceding claim, the set of 27 components comprising a plurality of first and 28 second clamping means of different sizes, each 29 adapted to clamp around a structural member of a different size, and a plurality of strut members 31 of different lengths.

32 33 34