GB2151326A - Pipe support - Google Patents

Abstract

A pipeline 1 mounting assembly comprises a joint-free bar structure of which the node points 2 are predominantly screw-threaded connections (30, Fig. 8). The bars of the structure are preferably pipes 11-26. <IMAGE>

Description

SPECIFICATION Support assemblies for pipelines The invention relates to a mounting assembly for pipelines, particularly those which are passed through a building, e.g. a power station, and have to be fixed there for example with respect to a base, a wall, a ceiling of the building or on a steel structure. Such assemblies should provide support in one or more of the possible displacement directions or rotational directions in or about the x, y and z axis. At a clamping fixed point a total fixing is present, so that therefore neither a displacement nor a rotation of the pipeline is possible.

Considerable loads frequently occur in pipeline mounting assemblies, which are to be transferred to the body of the building. For example differing operating conditions in the pipeline must be accommodated, such as thermal expansions and weight of the transport medium. Until now, for example, costly welded fabrications of sheets or sections have been used as the clamping fixed point, surrounding the pipeline which is to be fixed. In particular, owing to the great forces and moments to be taken into account in the design of the fabrication and also owing to thermal expansions, these solutions are heavy and expensive.A further considerable disadvantage of these welded fabrications is that frequently when being assembled they necessitate major adjustment work if the theoretical sizes of the body of the building and/or of the pipeline which were assumed for the dimension of the fabrication do not correspond exactly to the actual sizes.

In German published Specification No. 30 27 874 a pipeline mounting with bars is proposed, which are fastened via joints arranged on both ends of the bars between fixed points and the pipe, whereby the pipe is surrounded by a fixed frame or frame piece, on which the bars are articulated. The pipe is mounted in the frame so as to be freely movable in at least one direction of movement or rotation. Furthermore, at least two bars are to be rotatably mounted at a single articulation point on the frame or a fixed point about the same axis.

Compared with previous systems, this assembly can lead to savings on weight in the mounting, because merely tractive and compressive forces are transferred through the bars, and no bending moments. The latter are taken up by the frame. A disadvantage is the costly manufacture of the frame and its adjustment, which may become necessary, to the actual geometry of the pipe. In particular, the swivel joints provided to connect the bars with the frame or with a fixed point require an exact dimensioning of the bar lengths. Deviations of the building measurements from the theoretical values therefore also require adjustment work here which is frequently costly.

The present invention is directed at the provision of a pipeline mounting which is low in weight and is simple to manufacture and which does not require any, or only a minimal amount of adjustment work on assembly into a body of a building. To this end an assembly according to the invention comprises a jointfree bar structure of which the node points are predominantly screw connections. The bars of the structure may be pipes.

Preferably the majority of the node points comprise substantially spherical elements which are coupled to the bars of the structure by screw-threaded members. Each member is normally substantially coaxial with the bar to which it is coupled and may be rotatable in the end of the bar to which it is coupled.

Conveniently, the bar structure is adapted to be attached directly to lugs on a said pipe.

Using assemblies according to the invention any desired pipeline mountings are able to be produced through the framework method of construction, which mountings possess a high bearing strength and are of a substantially lower weight compared with conventional solutions (sheet welded fabrications). The reduction in costs which this already entails is enhanced by making provision for the connections between the individual elements of the framework (bars and connecting elements e.g.

to the base) to be constructed as rigid connections, primarily as screw connections. Costly joints are thereby avoided. Surprisingly, even with thermal alternating stress, according to the invention, despite the abandonment of movable joints between the framework elements, stresses are brought about in the bar support structure, which are only characterized by traction and pressure and do not show any significant deflections and moments, and therefore are able to be well controlled.

It is expedient to construct the bars of the bar support structure as pipes with circular cross-section to exploit their favourable strength properties. Further, the connections in the bar support structure may consist of spherical node elements with numerous tapped holes, into which screws or threaded elements may be twisted. Such elements may be mounted rotatably in the bar ends so as not to be displaced in the direction of screwing. Thereby, bars may be firmly connected with each other in various angular positions in a simple manner and so as to be assembled quickly. This type of screw connection is also very expedient with regard to assembly at the place of construction, because it allows tolerances in size to be balanced out with regard to the required bar lengths, without any expenditure. The usual amounts of deviation occurring in practice can be controlled in this manner.

Considerable advantages result if the pipeline mounting according to the invention is attached directly to lugs on the pipeline.

Thereby not only can costly frame constructions be saved in many cases as intermediate member for the introduction of force from the pipe into the bar support structure, but also assembly is facilitated. The weld seam between the lug and the pipeline will normally remain accessible for repeat tests. Auxiliary constructions for this, which were necessary hitherto, and which required additional expenditure, are superfluous.

The invention will now be described by way of example and with reference to the accompanying drawings wherein: Figure 1 shows a clamping fixed point mounting assembly according to the invention in axial cross-section of the pipeline; Figure 2 shows a plan view of the embodiment according to Figure 1; Figure 3 is a view in the direction of arrow A in Figure 1; Figure 4 is a view in the direction of arrow B in Figure 1; Figure 5 shows a axial bearing mounting assembly according to the invention in axial cross-section of the pipeline; Figure 6 is a view in the direction of arrow C in Figure 5; Figure 7 is a view in the direction of arrow D in Figure 5; and Figure 8 shows a node element for connections in the bar structures.

In Figure 1 a clamping fixed point is shown in front view. The pipeline 1 is held by the bar support structure of the pipeline mounting on the four lugs 3,4,5,6 of the pipeline 1 such that it can not be displaced in any direction. Nor can it rotate about any axis.

The lugs 3,4,5,6, which lie in pairs opposite each other, are situated in a plane containing the pipeline axis 9 (Figure 2). The threelegged framework stand formed from the bars 11,12,13 is firmly connected at its tip 10 with the lug 3, whilst the foot ends of the bars 11 ,12,1 3 are fastened to the body of the building (e.g. a steel girder). The lug 4 situated on the same side of the pipe 1 is screwed with the tip of a hinged support 14, the foot end of which in turn is firmly connected with the body of the building (Figure 3). The lug 6 lying opposite the lug 3 is fastened to the tip 18 of a framework triangle, the clamping surface of which lies parallel to the pipe axis 9 and the bars 19,20 of which are firmly connected on its foot end with the body of the building.Finally, the lug 5 lying opposite the lug 4 is firmly connected with the tip 15 of a further framework triangle, the clamping surface of which is directed vertically to the pipe axis 9 and the bars 16,17 of which are in turn firmly connected with the body of the building by their feet ends. In order to enable a favourable distribution of shearing forces onto the body of the building through the pipe mounting, the foot ends of the bars associated in each case with one of the lugs 3,5 or 6 may be connected with each other by tension bars (e.g. between bar 19 and 20 in Figure 4).

As the introduction of force into the bar support structure takes place directly via the short lugs 3,4,5,6 of the pipe 1, no significant bending moments are produced in the pipe mounting fabrications. The individual bars merely have to take up and pass on tractive or compressive forces. A particular advantage of this solution is that deviations of the pipe geometry from the theoretical values (such as, for instance, non-roundness of the pipe), do not lead to adjustment work on assembly.

The connection of the bars with each other is brought about in each case by means of spherical node elements 2, which are welded or screwed onto the lugs 3,4,5,6 or on support plates for the connection with the body of the building. The node elements 2 have bores, as shown in Figure 8, into which threaded members 30 may be screwed, which are mounted coaxially and rotatably but in a manner which precludes displacement in the direction of screwing in the ends of the bars 28,29. Thereby, various bars can be easily connected with each other in the respective desired angular position. Within the permissible range between minimum and maximum screw-in depth of the screws 30 into the node elements 2, the bar lengths can be adapted, without great expenditure, to measurements of the body of the building which deviate from the theoretical values.

Figures 5, 6 and 7 show in various views an axial bearing for the pipeline 1. The object of such a bearing is to secure the pipeline 1 rigidly against displacements in the direction of the pipe axis 9 or to hold it in this direction by means of spring- or constant- shackles. The forces necessary for the axial securing of the pipe 1 are introduced in the bar support structure via the lugs 7,8 lying opposite each other. The bar support structure can be div ided into five component bar support structures, which in each case extend over one of five surfaces of a parallelepiped which sur rounds the pipe 1, with the pipeline axis 9 being the median perpendicular of the top surface of the parallelepiped. The component bar support structure of the top surface con sists of four congruent bar triangles, the short sides of which (bars 21,21',22,22' 23,23',24,24') in each case lie on the edges of the parallelepiped and which in each case are connected with each other in pairs at one corner and are attached with a further corner to one of the lugs 7,8.

In the lateral surfaces of the parallelepiped, component bar support structures are ar ranged, which in each case consist of two inversely congruent, right-angled framework triangles, the one short side of which in each case is a bar 21,21',22,22',23,23',24,24' of the component bar support structure of the top surface and the other short side of which in each case is a common bar 25,25', 26,26'. The length of the bars 21,21',22,22' on the side of the lugs 7,8 is thereby selected to be greater than the length of the bars 23,23',24,24', whereby the necessary space is created for the two constant shackles 27 (or spring shackles, guide rods or suchlike) arranged parallel to the pipe axis 9, on which the bar support structure is suspended. The two suspension points for the spring shackles 27 lie on a parallel to the pipeline axis 9, which runs through the centre of the shorter edges of the top surface (in Figure 5 the constant shackles 27 are not shown). By this means, in turn, a transfer of force which is practically free of bending moments is achieved from the pipe 1 to the body of the building, although the forces holding the pipe 1 act at a clear distance from the pipeline axis 9.

Claims (13)

1. A support assembly for securing a pipeline comprising a joint-free bar structure of which the node points are predominantly screw connections.

2. A support assembly according to Claim 1 wherein the bars of the structure are pipes.

3. A support assembly according to Claim 1 or Claim 2 wherein the majority of the node points comprise substantially spherical elements which are coupled to the bars of the structure by screw-threaded members.

4. A support assembly according to Claim 3 wherein each member is substantially coaxial with the bar to which it is coupled.

5. A support assembly according to Claim 3 or Claim 4 wherein each member is rotatable in the end of the bar to which it is coupled.

6. A support assembly according to any preceding Claim wherein the bar structure is adapted to be attached directly to lugs on a said pipe.

7. A support structure for securing a pipeline substantially as described herein with reference to the accompanying drawings.

8. A pipeline mounted on a base using a support structure according to any preceding Claim.

9. A pipeline according to Claim 8 in which the bar structure defines two framework triangles, each extending from a lug on the pipeline the plane of one triangle being parallel and the plane of the other being perpendicular to the pipeline axis.

10. A pipeline according to Claim 8 or Claim 9 wherein the bar structure defines at least one three-dimensional stand having three bars extending from one lug on the pipeline to spaced points on the base.

11. A pipeline according to Claim 9 and Claim 10 wherein the bar structure is attached to four lugs disposed at opposite ends of spaced parallel diameters on the pipeline, the two framework triangles extending from adjacent lugs on one side of the pipeline and the stand extending from one of the other lugs, an hinged support extending from the fourth lug.

12. A pipeline according to Claim 8 wherein the bar support structure is attached to four lugs lying opposite each other in pairs in relation to the pipeline axis and in a plane with the pipeline axis to form a clamping fixed point, whereby the first lug is connected with the tip of a three-legged framework stand, the second lug lying on the same side of the pipeline is connected with one end of a hinged support, the third lug lying opposite the second lug is connected with the tip of a first framework triangle standing with its clamping surface vertically to the pipeline axis, and the fourth lug is connected with the tip of a second framework triangle standing with its clamping surface parallel to the pipeline axis.

13. A pipeline according to Claim 8 mounted on the base to form an axial bearing, and wherein the bar support structure is divided into five component bar support structures, which each extend over the top surface or one of the four lateral surfaces of a parallelepiped surrounding the pipeline, the pipeline axis running vertically through the central point of the top surface, and four congruent rectangular framework triangles being arranged in said top surface, the short sides of each triangle lying on the edges of the parallelepiped and connected with each other in pairs on one corner and with a further corner are attached to one of two lugs of the pipe lying opposite each other, each component bar support structures arranged in the lateral surfaces of the parallelepiped consisting of two inversely congruent rectangular framework triangles, one short side of each being a bar of the component bar support structure in the top surface and the other short side of each being a common bar, and wherein the length of the edges of the top surface lying on the side of the lugs is greater than the length of the other edges of the top surface, two bars, spring shackles, constant shackles, guide rods or impact brakes, lying parallel and symmetrically to the pipe axis being connected with the bar support structure in fastening points, which in each case lie on a straight line running through the centre of the shorter edges of the top surface parallel to the pipe axis.