GB2034843A

GB2034843A - Flexible Pipe Joints

Info

Publication number: GB2034843A
Application number: GB7936785A
Authority: GB
Original assignee: PFORZHEIM METALLSCHLAUCH
Current assignee: PFORZHEIM METALLSCHLAUCH
Priority date: 1978-11-09
Filing date: 1979-10-23
Publication date: 1980-06-11
Also published as: CH640928A5; IT1122640B; IT7924708A0; FR2441120B1; DE2848561A1; NL181681B; NL7906228A; FR2441120A1; GB2034843B; DE2848561C2; NL181681C

Abstract

This discloses a flexible pipe joint for absorbing stress in pipe-lines. It is capable of sustaining high loads and it does not require its tie bars to be welded or secured with screwed nuts. It comprises a bellows unit 1, and a transverse plate 3, 4 at each end of the unit, the plates being connected to one another by articulated tie rods. In a preferred design each tie rod consists of a thicker limb 6 connected to a pair of thinner limbs 7, 8 via a pivot 9. The tie bars are secured relative to the plates as a result of their projecting through the plates and by provision of stops which bear against the sides of the plates that face away from the bellows. <IMAGE>

Description

SPECIFICATION Compensator This invention relates to a compensator for absorbing stress in pipe-lines, consisting of at least one bellows structure and of two terminallypositioned appendages, the appendages each comprising a transversely-extending plate which surrounds the bellows; and the plates are movably connected to each other by tie bars which extend on each side of the bellows structure, for which purpose the tie bars each consist of a number of parts which are articulated to one another, the tie bars being secured, at their ends, in complementary openings formed in the plates.

Compensators can be designated as lateral or angular compensators according to the construction of their tie bars and according to the way in which the tie bars are articulated to the plates. In the case of lateral compensators the tie bars are, in the lighter form of construction for low pressures and temperatures, fixed at their projecting ends by nuts which have been screwed down and with the interposition of spherical washers. If the compensator is to be capable of sustaining higher loads, the ends of the tie bars should be welded in the corresponding openings of the plates. In the case of tie bars of small cross section a weld seam suffices for transmitting the tensional forces.However, if tie bars of larger cross section have to be used in order to enable the compensators to sustain higher loads, the layers should be welded together, preferably by hand; this is time-consuming and expensive. The same problem can occur in the case of angular compensators.

We have now designed a compensator which can be structurally simple and inexpensive. Even when designed for very high loads, the welding process can be dispensed with (this welding process has hitherto been necessary for the purpose of connecting the tie bars together) or at least to be markedly reduced.

This can be achieved by an arrangement of tie bars susceptible of insertion, by their ends at the articulation point and from the side of the plate facing away from the bellows structure, through the openings of the plates; the other end of the tie bars has a hammer-like extension by means of which the tie bars are supported from the side of the plates facing away from the bellows structure.

By means of the form of construction proposed according to the invention the tie bars can be supported from their plates effectively, in stable manner, and in a surprisingly simple way; the welding process, which has hitherto beew necessary, can be entirely dispensed with, so that assembly is simplified to a remarkable degree. At the same time the tie bars can be manufactured in a very inexpensive way, as the hammer-like extension can, in one and the same working step, be integrally formed with the tie bar itself. The way in which the hammer-like extension projects laterally will depend on the magnitude of the forces to be sustained by the compensator Such a lateral projection can be provided in all directions or, as is preferable, only at the narrow faces of the tie bars.This positioning of the projections on the narrow faces of the tie bars affords the advantage that the tie bars together with their extensions or projections can be formed by cutting. According to whether, in each instance, we are concerned with an angular or lateral compensator, the tie bars, which are inserted into the plates, are either interconnected laterally by a transverse pin, or are articulated to a respective intermediate element by way of two such transverse pins.

Conveniently, the individual tie bar parts, like those of conventional tie bars, have a rectangular cross-section. The associated openings in the plates are, conveniently, rectangular slots cut out from these plates.

It is advantageous, in the case of angular compensators, if the tie bars consist, on one side of the point of articulation, of two identical bars, whose combined strength approximately corresponds to the strength of the single-part tie bar on the other side of this point of articulation.

The single-part tie bar will extend between the two identical bars. This permits a very simple construction of the joint or articulation. Also, it is possible in this way to cut both plates using the same template.

The invention is further illustrated, with reference to the accompanying drawings, in which: Figure 1 is a side elevation of an angular compensator according to the invention; Figure 2 is a detail from the part of Figure 1 marked X, but viewed at 900; Figure 3 is a plan view of the upper plate of the compensator shown in Figure 1, and Figure 4 is a view, partially in cross-section, of a lateral compensator.

An angular compensator is shown in Figure 1, which consists of a bellows structure 1 having two cylindrical appendages 2 and 3. Plates 4, 5 are mounted on the appendages 2 and 3. Each plate 4, 5 is welded to its associated bellows appendage, and, in the device illustrated, has an approximately oval outline (see Figure 3).

The pivotal connection between the two plates is effected by way of tie bars, which will usually be indentical, and which are arranged on each side of the bellows 1. Each tie bar consists of a relatively thick bar 6 and two less thick bars 7 and 8; the thicker bar 6 leads to one of the plates 5, and the two thinner bars 7 and 8 lead to the other plate 4. The bars overlap in the region between the two plates 4 and 5, generally midway between the plates. The bar 6 is positioned between the two thinner bars 7 and 8, where hinging is achieved by a transverse pin 9. At the other end the bars each have a hammer-like extension 6a, 7a, or 8a, by means of which the bars are supported from the side of the plates 4, 5 facing away from the bellows.In the arrangement illustrated in Figure 1, the pair of thinner bars is attached to the top plate at the left-hand side of the device, and to the bottom plate at the righthand side of the device.

As the two plates 4, 5 and the two tie bars are turned through 1 800 relative to each other (i.e.

they are inverted relative to one another), a thick bar 6 or 6' and two thinner bars 7, 8 and 7', 8' are secured to each plate. Thus, the plates 4 and 5 may be identically shaped, and their slots 10 to 12, serving for the insertion of the bars 6 to 8, can be cut out by means of a template.

Figure 2 illustrates the hammer-like extension at the ends of the tie bar 6, and the other bars have similar extensions. The hammer-like extension 6a lies flat against the plate 5, thereby ensuring a low-stress transmission of power between tie bar and plate. Conveniently, the tie bar can be welded to the plate, either directly or by way of its extension; the weld seam is provided as a finish or trim and need not have any supporting function. Also, a weld seam can protect the slots from corroding.

Figure 4 illustrates a lateral compensator according to the invention. The lateral compensator illustrated consists of two bellows 1 a and 1 b, which are interconnected by way of a tubular section 13. A tubular appendage 14, 1 5 is arranged on the outer end of the bellows 1 a, 1 b respectively. Analogously to the arrangement of Figure 1, the tubular extensions 14, 15 carry plates 16, 17 respectively, these plates preferably being shaped as shown in Figure 3. Due to the structure of the tie bars illustrated, this embodiment shows one slot arranged on each side of the plate for the tie bars. The tie bars each consists of two central bars 1 8, the inner of which supports the tubular section 13 at two points. At their two ends these bars 18 are articulated, by way of transverse pins 19, 20, to the rods 21, 22 respectively. These rods 21, 22 constitute the ends of the tie bars and are supported, by way of their hammer-like extensions 21 a, 22a, from the sides of the plates facing away from the bellows, as in the arrangement described above.

The compensator according to the invention can be assembled by inserting the ends of the rods 6 to 8 or 21 and 22, which provide the point of articulation through the plates, from the sides of the plates facing away from the bellows. The ends of the bars are then either directly connected to one another, e.g. by transverse pins, or are indirectly connected to one another via intermediated bars 18.

Claims

1. Compensator for high loading, consisting of at least one bellows structure, and of two terminally positioned appendages, the appendages each having a transversely-arranged plate which surrounds the appendage, and the plates are movably connected to each other by tie bars which run on each side of the bellows structure, for which purpose the tie bars each consist of a number of parts which are articulated to each other, and the tie bars are fixed, at their ends, in complementary openings formed in the plates, characterised in that the tie bars can be inserted, by their ends lying closer to the point of articulation and from the side of the plate lying remote from the bellows structure through the openings of the plates and the other end of the tie bars has a hammer-like extension by means of which the tie bars are supported from the side of the plates lying remote from the bellows structure.

2. Compensator according to claim 1, characterised in that the tie bars are rectangular in cross-section, and the openings in the plates are cut rectangular slots.

3. Compensator according to claim 1 or claim 2, characterised in that the hammer-like extension only projects at the narrow places of the tie bars.

4. Compensator for angular compensation, according to claim 1 or claim 2, characterised in that the tie bars on one side of the point of articulation consist, in each case, of two identical bars whose combined strength approximately corresponds to the strength of a single-part bar lying on the other side of the said point of articulation.

5. Compensator according to claim 4, characterised in that the plates have the same shape.

6. A compensator for absorbing stress in pipelines, having a bellows unit, and a transverse plate at each end of the unit, the plates being connected to each other by articulated tie bars; in which securing of each bar relative to the relevant plates results from projection of the ends of the bar through the plates and from the presence of a stop at each end which bears against the faces of the plates facing away from the bellows.

7. A compensator according to claim 6, in which the stops are integral with the bars.

8. A compensator according to claim 6 or claim 7, in which the stops extend from the bars only in the plane in which the relevant bar articulates.