GB2188388A

GB2188388A - Flanged pipe joint

Info

Publication number: GB2188388A
Application number: GB08707209A
Authority: GB
Inventors: Raymond Edward Johnson
Original assignee: Barnard Pipeline Tech
Current assignee: Barnard Pipeline Tech
Priority date: 1986-03-27
Filing date: 1987-03-26
Publication date: 1987-09-30
Also published as: GB8707209D0

Abstract

A pipe joint is formed by a pair of flanges (4, 5) attached respectively, for example, to a pair of pipes (1, 2). The flanges have opposed faces (4A, 5A) one of which has a circumferentially extending groove (8) containing a seal element (9) which protrudes outwardly of the groove prior to assembly of the joint, and draw means in the form of bolts clamping the flanges together, whilst simultaneously compressing the seal element (9) into the groove, in order to bring said opposed faces directly into firm clamped engagement. <IMAGE>

Description

SPECIFICATION Pipe joint This invention relates to a pipe joint for use in connecting together lengths of pipe and has particular application in the water and gas industries in which extended pipe assemblies are often formed using a number of discrete pipe lengths.

In a common conventional arrangement, the pipe ends are provided with generally radially extending flanges and a pipe joint is formed by clamping the flanges, usually by means of bolts, onto an interposed gasket which forms a seal between the opposed flange surfaces.

The modern trend towards the use of synthetic rubber gaskets has led to problems due to the inherent lack of elastic memory of some of the materials used which can result in a reduction of tension occurring in the joint bolts leading to joint leakage in extreme cases. This problem can be exaggerated when the pipe assembly is installed vertically in a bore hole, since the weight of the pipe and associated equipment, suchas a pump, imposes additional load on the pipe joints with a consequent increased tendency for the joint parts to move and cause leakage.

An object of the invention is to provide a pipe joint in which the aforesaid problem is minimised or avoided.

According to the invention, a pipe joint includes a pair of flanges having opposed faces, one of which faces has a circumferentially extending groove containing a seal element which protrudes outwardly of the groove prior to assembly of the joint, and draw means operable to clamp the flanges together, whilst simultaneously compressing the seal element into the groove, in order to bring said opposed faces directly into firm clamped engage- ment.

Said clamp means is preferably one or more bolts interconnecting the flanges. The flanges may conveniently be of generally octagonal shape with bolts conveniently disposed in the regions of at least some of the apices thereof.

Additionally, the invention embraces a pipe assembly incorporating one or more pipe joints of the invention.

The invention will now be described by way of example, with reference to the accompanying drawings in which: Figure 1 is a side elevation of one form of the pipe joint of the invention shown interconnecting a pair of pipes; Figure 2 is an elevation of the left-hand end of the assembly of Fig. 1; Figure 3 is an elevation of the right-hand end of the assembly of Fig. 1; Figure 4 is part of a cross-section along the line 4-4 of Fig. 3 to an enlarged scale, and Figure 5 illustrates a typical installation employing a number of pipe joints of the invention.

Referring to Fig. 1 of the drawings, this shows a pair of pipes 1, 2 interconnected by a pipe joint illustrated generally at 3. The pipes 1 and 2 are provided with respective circumferential radially projecting flanges 4 and 5 which are clamped together by any suitable clamping means shown in this embodiment as bolts 6 passed through holes 7 spaced circumferentially around the flanges, preferably equi-distantly, as shown, the bolts co-operating with nuts 6A. An alternative clamping device incorporating jaws or other suitable clamps may be employed, if required. Each flange is provided with a cable clamp or guide 3A.

As will be seen more clearly from Fig. 4, the flange 4 is provided with a circular circum- ferential groove 8 formed in its outer end face, the groove being concentric with a circle of larger diameter around which the bolt holes 7 are disposed. The groove 8 contains a seal 9 of any convenient shape which, prior to assembly of the pipe joint, protrudes axially from the groove, in the manner illustrated. A typical seal for use in the joint of the invention may have a domed portion 9A projecting from a flat base 9B, as shown, the base 9B resting on the bottom of the groove 8. The corresponding opposed surface 5A of the flange 5 is ungrooved and uninterrupted, apart from the bolt holes 7.

When a pair of flanges 4 and 5 are brought together and interconnected by the bolts 6, tightening of the bolts causes the seal 9 to be compressed into the groove 8, enabling the opposed metal surfaces 4A, 5A of the flange to be brought tightly together, as illustrated in Fig. 1. Such metal to metal contact between the flanges enables a very large and even clamping force to be applied between the flanges, without risk of damaging the seal 9 which now lies wholly within the groove 8 and bears upon the end surface 5A of the flange 5 to provide a fluid tight seal between the flanges.By reason of the very substantially increased tightening force which can be applied to the joint of the invention, as compared with many conventional arrangements, there is very much less risk of the joint becoming loosened, even when pipes connected by one or more such joints are arranged vertically, as for example in a bore hole. A further advantage of the joint of the invention is that adequate tightening can be achieved by the use of as few as four bolts, which means that the flanges 4 and 5 may be of generally octagonal shape, instead of circular as is conventional, enabling a significant weight saving to be achieved by reason of the reduced mass of metal 10 present in the flanges.

Fig. 5 shows a typical application of the pipe joint of the invention to a pipe assembly, illustrated generally at 20 extending down a bore hole 21 and consisting of a number of pipe lengths 22 joined together by pipe joints 23 of the invention. The lower end of the pipe is connected to a pump 24 which is operable to pump water 25 at the bottom of the bore hole, the pipe assembly being mounted at the upper end of the bore hole on a suitable base 26, as of concrete for example, by means of a mounting flange 27.

The pipe assembly continues beyond the up per end of the flange 27 in a direction at right angles to the bore to deliver water into a tank 28. An electrical control unit 29 is provided to supply an electric motor associated with the pump 24 via a wire 30 which is clamped at intervals by cable clamps 31 along the pipe assembly 20. The pipe joint of the invention has been found to be particularly useful in this type of vertical pipe installation, largely or entirely avoiding the joint leakage problems found in many conventional types of joint.

Although only a single groove and seal in one of the flanges has been described, a plurality of such grooves and seals may be provided. Moreover, a single seal or plurality of seals may also be provided in the opposed surfaces of both flanges, the seals having different diameters so that each seal is opposite to and seals against a solid part of the facing flange.

Claims

1. A pipe joint comprising a pair of flanges having opposed faces, one of which faces has a circumferentially extending groove containing a a seal element which protrudes outwardly of the groove prior to assembly of the joint, and draw means operable to clamp the flanges together, whilst simultaneously compressing the seal element into the groove, in order to bring said opposed faces directly into firm clamped engagement.

2. A pipe joint according to Claim 1 wherein said clamp means is one or more bolts interconnecting the flanges.

3. A pipe joint according to Claim 1 or Claim 2 wheren the flanges are of generally octagonal shape.

4. A pipe joint according to Claim 1 wherein the flanges are generally octagonal shape and the clamp means is a plurality of bolts interconnecting the flanges in the regions of at least some of the apices thereof.

5. A pipe joint according to any one of the preceding claims wherein the seal element has a flat base engaging the bottom of the groove and a generally domed portion extending outwardly of the groove prior to compression of the element by the flanges.

6. A pipe joint according to any one of the preceding claims wherein the other of the opposed flange faces is ungrooved.

7. A pipe joint substantially as hereinbefore described with reference to Figs. 1 to 4 of the accompanying drawings.

8. A pipe assembly including two or more pipes interconnected by a pipe joint according to any one of the preceding claims.

9. A pipe assembly substantially as hereinbefore described with reference to Fig. 5 of the accompanying drawings.