GB2238620A

GB2238620A - Leak testing pipe joints

Info

Publication number: GB2238620A
Application number: GB8927094A
Authority: GB
Inventors: Kenneth Stanley Gibson
Original assignee: Furmanite International Ltd
Current assignee: Furmanite International Ltd
Priority date: 1989-11-30
Filing date: 1989-11-30
Publication date: 1991-06-05
Anticipated expiration: 2009-11-30
Also published as: NO922150L; GB2238620B; WO1991008458A1; AU6752490A; GB8927094D0; NL193673C; NO304565B1; NL9022044A; NL193673B; NO922150D0

Abstract

A joint testing apparatus (10) comprises two hubs (26, 28) secured together by hydraulic nuts and bolts (30, 30A), a rim member (36) being sealingly located between the two hubs. The hubs are attached to a hollow tube (42) enabling the apparatus to be located adjacent a joint (18) to be tested. The hydraulic nuts (30) and the rim member (36) can be pressurised from a hydraulic pressure source remote from the joint (18).

Description

IMPROVEMENTS IN OR RELATING TO JOINT TESTING APPARATUS This invention relates to apparatus for testing joints.

In particular though not exclusively the invention is concerned with testing joints between individual lengths of piping which make up oil or gas pipe lines. It is common for such individual lengths of ducting to be joined at their ends by means of bolted flanges or welding.

The present invention seeks to provide a joint testing apparatus which can be readily located adjacent a joint to be tested and which can be operated at a location remote from the joint to be tested.

Accordingly the present invention provides a joint testing apparatus comprising two relatively moveable hubs which are attached together, a rim member sealingly located between the two hubs, actuating means arranged to move the hubs relative to one another, a support structure for the hubs and means for pressurising a space between the rim member and the joint to be tested, the acuating means being operable from a position remote from the joint under test.

The hubs can comprise a compression hub and a locating hub, and each hub can have a circular recess in which a lip of the rim member is located.

A seal member can be located in each recess.

The support structure can comprise a hollow tube attached to one of the hubs and the hollow tube can be provided with access ports for the actuating means.

The actuating means can comprise hydraulic nuts operated by a supply of hydraulic pressure.

The means for pressurising the space between the seal member and the joint to be tested can also comprise a supply of hydraulic pressure.

The support structure can be provided with lifting means, and securing means enabling joint testing apparatus to be secured in position.

The present invention will now be more particularly described with reference to the accompanying drawing in which Fig. 1 shows a sectional side elevation of one form of joint testing apparatus according to the present invention, and Fig. 2 shows a view on arrow A in Fig. 1.

Referring to the drawing, a joint testing apparatus 10 is shown located in the bore 12 of a valve 14 to which a duct 16 is attached by means of a joint 18.

The joint 18 comprises a flange 20 attached to the valve body 14, the flange 20 having an annular flat face 20A mating with a corresponding annular face 22B on a flange 22 attached to the duct 16. A sealing ring 24 is located in annular recesses in the faces 20A and 22A of the flanges 20 and 22 respectively. The flanges 20 and 22 are secured together by bolts or nuts and bolts (not shown).

The joint testing apparatus 10 comprises an annular compression hub 26 and an annular locating hub 28 which are secured together for relative movement by eight hydraulic nuts 30. The hubs 26 and 28 form annular recesses 26A and 28A respectively with a rim member. Seals 32 and 34 are located in the annular recesses 26A and 28A respectively.

The rim member 36 is located between the hubs 26 and 28 and is of an integral construction comprising lips 36A and 36B and a circular rib 36C. The lip 36A is located in the recess 26A and the lip 36B is located in the recess 28A. The lips 36A and 36B are relieved to create an annular space 37 between the rim member 36 and the bore 12.

Each of the hydraulic nuts 30 is provided with a supply of hydraulic pressure (not shown). The seal member 36 is also provided with a supply of hydraulic pressure via a pipe 38 which terminates at one end in a connector 40 in the rib 36C allowing access of hydraulic fluid under pressure to the space between the flexible seal 36 and the joint 18. The other end of the pipe 38 is connected to a supply of hydraulic pressure (not shown).

The two hubs 26 and 28 which are urged apart by coil springs 42 but which are held together by bolts 30A and hydraulic nuts 30 are attached to a support structure comprising a tube 43 attached to an annular end plate 44. The end plate 44 is provided with two threaded boxes 46 in which eye bolts 48, only one of which is shown are located. The end plate 44 also has a ring of equispaced holes 50 enabling the support structure to be bolted to a flange 52 of the valve 14. The tube 43 is provided with access ports 54 adjacent to each hydraulic nut 30 enabling the nuts to be conveniently connected to a source of hydraulic pressure.

In use, prior to the joint tester being positioned adjacent the joint to be tested, the pipe 38 is attached to the connector 40 so that the pipe 38 is easily accessible from the central opening in the end plate 44 and similarly the nuts 30 are all connected to the source of hydraulic pressure. Using suitable lifting gear and using the eye bolts 48, the joint testing apparatus 10 is positioned in the bore 12 of the valve 14 and the plate 44 is attached to the flange 52 by means of nuts and bolts or bolts only (not shown) passing through the openings 50. The length of the tube 42 is chosen so that the flexible seal 36 will be positioned centrally of the joint 18.

The hydraulic nuts 30 are then operated by providing each of them a supply of hydraulic pressure so that the hubs 26 and 28 move towards one another against the loading exerted by the coil springs 42. This movement causes the rim 36 to compress the seals 32 and 34 seals 32 and 34 in the axial sense, forcing the seals to expand radially, to seal agains the bore 12. Hydraulic pressure is then supplied to the space 37 via the pipe 38 and the connector 40 in the rim 36, whilst maintaining the pressure on the hydraulic nuts.

The hydraulic pressure on the nuts is maintained and the space is then pressurised to a predetermined pressure and maintained at that pressure for a predetermined period of time. The pressure applied to the space and the duration of application of that pressure is chosen to meet the design specifications of the joints. If there is no visible leak of hydraulic fluid from the joint 18 and no reduction in pressure for the predetermined time the joint 18 will be considered to be satisfactory.

It will be appreciated that as the hydraulic nuts 30 and the seals can all be pressurised remotely from the actual location of the joint, the joint tester according to the invention allows joints which are difficult to reach to be satisfactorily tested.

It will also be appreciated that the hubs 26 and 28 can be accurately positioned adjacent to joints to be tested by appropriate choice of length of the tube 43.

It will also be appreciated that a joint tester according to the present invention can test short lengths of ducting and avoids the need of blanking off whole lengths of ducting.

The joint testing apparatus according to the present invention can be used not only in oil and gas pipelines but for any joint and for a wide range of pipe diameters, for example 0.3m to 3m, but is not limited to use for such pipe diameters.

The joint testing apparatus has been described with reference to the apparatus being secured in position but it is not necessary for the apparatus to be secured to a pipeline having a joint under test.

Claims

1 A joint testing apparatus comprising two relatively moveable hubs attached together, a rim member sealingly located between the two hubs, actuating means arranged to move the hubs relative to one another, a support structure for the hubs and means for pressurising a space between the rim member and a joint to be tested, the actuating means being operable from a position remote from the joint under test.

2 A joint testing apparatus as claimed in claim 1 in which the hubs comprise a compression hub and a locating hub secured together by nuts and bolts and urged apart under a spring load.

3 A joint testing apparatus as claimed in claim 2 in which each hub has an annular recess in each of which a lip of the rim member is located.

4 A joint testing apparatus as claimed in claim 2 or claim 3 in which a seal member is located in each recess.

5 A joint testing apparatus as claimed in any one of the preceeding claims in which the support structure comprises a hollow tube attached to one of the hubs.

6 A joint testing apparatus as claimed in claim 5 in which the hollow tube has access ports adjacent each actuating means.

7 A support structure as claimed in any one of the preceding claims in which the actuating means comprises a plurality of hydraulic nuts.

8 A joint testing apparatus as claimed in any one of the preceding claims in which the means for pressurising the space between the rim member and the joint to be tested comprises a source of hydaulic pressure located remotely from the joint under test.

9 A joint testing apparatus as claimed in any one of the preceding claims in which the support structure has lifting means enabling the apparatus to be inserted into and removed from a joint to be tested.

10 A joint testing apparatus as claimed in any one of the preceding claims in which the support structure includes securing means enabling the apparatus to be attached to a structure including a joint to be tested.

11 A joint testing apparatus as claimed in claim 10 in which the securing means comprises an annular plate attached to the hollow tube, the annular plate being provided with a plurality of openings enabling the securing means to be bolted in position.

12 A joint testing apparatus constructed and arranged for use in operation substantially as herein described and with reference to the accompanying drawing.