GB2240834A

GB2240834A - Valve apparatus

Info

Publication number: GB2240834A
Application number: GB9003053A
Authority: GB
Inventors: Kenneth Stanley Gibson
Original assignee: Furmanite International Ltd
Current assignee: Furmanite International Ltd
Priority date: 1990-02-10
Filing date: 1990-02-10
Publication date: 1991-08-14
Anticipated expiration: 2010-02-10
Also published as: NL194512C; NO910523D0; GB9003053D0; NO910523L; NO172762B; NL194512B; GB2240834B; NL9100106A; NO172762C

Abstract

A valve apparatus (12) particularly for a plug apparatus (2) of a pipeline (4) comprises a housing which includes a primary non-return valve (40) and three secondary non-return valves (54). A sealable space (28) is located between the primary valve (40) and the secondary valves (54). A pressurised medium is supplied through a hollow inlet shaft (32) to flow through the non-return valves (40, 54) to inflatable tyres (6, 8) of the plug apparatus (2). The pressure in the cavity (28) can be reduced by remote operation of the primary valve (40) in order to test any leakage through the valves (54) and the valve (40) by changes in pressure in the cavity (28). The pressure in the plug apparatus (2) is released by remote operation which opens the valves (54) and allows a pressurised medium to escape from the valve apparatus (12) by-passing the non-return valve (40). A sleeve (74) is moved to force a sealing plate (36), which carries the primary valve (40), against the action of a spring (59) and so open the secondary valves (54) through operating pins (56). <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO VALVE APPARATUS This invention relates to valve apparatus for use in connection with pressurised medium circuits, for example hydraulic circuits, where the valve apparatus can be operated remotely from the location of the valve apparatus.

For example plugs are frequently used in oil and gas pipelines to isolate selected sections of the pipelines. The plugs used in these circumstances frequently comprise one or more inflatable tyres which are inflated by an hydraulic medium such as water or oil. It is obviously necessary that the pressure in the plug system is maintained and that any loss of pressure is detected.

It is usual for an hydraulic medium to be supplied to the plug system through two non-return valves known as a "double block" arrangement. The provision of two non-return valves in series clearly assists in reducing the chances of leakage from the plug through the hydraulic supply system.

It is necessary to be able to test for any leakage from the plug system through both of the non-return valves. This can be carried out by reducing the pressure in the communication line between the first and second non-return valves, as a subsequent rise in pressure in this space indicates a leak from the non-return valve nearest the plug system whilst a decrease in pressure indicates a leak in the non-return valve furthest from the plug system.

It is also desirable for such a valve arrangement to be placed as close as possible to the plug system for maximum safety. However such a location means that it is not always easy to gain access to the non-return valves so that the communication line between them can be reduced in pressure.

The present invention seeks to provide a valve apparatus including at least two non- return valves arranged in series, the valves being remotely operable so as to at least enable the line of communication between the said two valves to be reduced in pressure.

The present invention also seeks to provide a valve apparatus which enables the pressure in a pressurised apparatus to be relieved by remote operation of both of the valves in the valve apparatus.

Accordingly the present invention comprises a valve apparatus comprising a housing, a primary and at least one secondary non-return valve mounted in the housing, a sealable space in the housing between the primary nonreturn valve and the at least one secondary non-return valve, inlet ducting to allow a pressurising medium to flow into the housing through the primary non-return valve and the at least one secondary non-return valve and the sealable space to the apparatus to be pressurised, first outlet ducting to allow pressurised medium to flow from the sealable space through the primary non-return valve and out of the valve apparatus, second outlet ducting to allow a pressurised medium to flow from the pressurised apparatus through the at least one secondary nonreturn valve into the sealable space and out of the valve apparatus by-passing the primary non-return valve, the primary non-return valve being operable remotely from the valve apparatus to open the primary nonreturn valve and allow pressurised medium to escape from the sealable space through the primary non-return valve and the first outlet ducting, and the at least one secondary non-return valve being operable remotely from the valve apparatus to open the at least one secondary non- return valve and allow pressurised medium to escape from the valve apparatus via the first and second outlet ducting.

The sealable space can comprise a cavity in the housing, one wall of which can comprise a movable sealing plate.

The moveable sealing plate can have an opening extending through the plate and the primary non-return valve can be located in the opening.

The sealing plate can include internal passages comprising the second outlet ducting.

The sealing plate can include sealing means to make a seal between the sealing plate and a wall of the cavity.

The valve apparatus can include spring means to urge the sealing plate into sealing contact with the said cavity wall.

The secondary non-return valve can be located in a through opening in a further wall of the cavity, the at least one secondary non-return valve having operating means to allow the secondary non-return valve to be opened.

The valve apparatus can include a secondary non-return valve housing locating in the cavity and including guide means for the operating means the secondary non-return valve.

The secondary valve housing can have a passage providing communication between the sealable space and the secondary non-return valve.

The valve apparatus can have locating means provided between the secondary valve housing and the sealing plate.

The valve apparatus can include sleeving located in the inlet ducting, the sleeving having an opening to allow access for a tool operable remotely from the valve apparatus to depress the primary non-return valve against the load of the spring means and allow pressurised medium in the sealable space to be released from the valve apparatus via the primary non-return valve and the first outlet ducting.

The sleeving can include through openings comprising the second outlet ducting.

The sleeving can be provided in two portions, a first portion secured to the housing and a second portion operable remotely from the valve apparatus to move the sealing plate against the load exerted by the spring means out of sealing engagement with the cavity wall, and to open the secondary non-return valve to allow pressurised medium to flow through the secondary non-return valve into the sealable space and to be released from the valve apparatus via the second outlet ducting.

Pressure indicating means can be provided in communication with the sealable space to indicate the pressure therein.

Pressure indicating means can also be provided in communication with the through openings in the secondary non-return valve housing to indicate the pressure between the secondary non-return valve and a pressurised apparatus.

The valve apparatus can include a plurality of secondary non-return valves each secured in a through opening in the valve housing and having a respective passage in the secondary non-return valve housing in communication with the sealable space.

The present invention will now be more particularly described with reference to the accompanying drawings in which: Fig. 1 shows a section of pipeline with a plug, and valve apparatus according to the present invention located therein, Fig. 2 shows the valve apparatus illustrated in the Fig. 1 in detail in a first operating position, Fig. 3 shows a portion of the valve apparatus shown in Fig. 2, the valve apparatus being in a second operating position, and Fig.4 shows the valve apparatus of Fig. 2 in a third operating position.

Referring to Fig. 1 a plug apparatus 2 is located in a pipeline 4. The plug apparatus 2 has three inflatable gripping tyres 6, three inflatable sealing tyres 8, and a pressurisable central seal 10. A valve apparatus 12 according to the present invention is attached directly to a bulkhead 14 of the plug apparatus, the other end of which us closed off by a bulkhead 16 having a polyurethane nose cone 16A.

The valve apparatus 12 is connected hydraulically to the tyres 6, 8 as will be described below.

Referring now particularly to Fig. 2, the valve apparatus 12 has a housing comprising an upper housing 18 and a lower housing 20, the upper and lower housings being secured together by bolts 22 which also secure the valve housing directly to the bulkhead 14. A further ring of bolts 24 also secure the lower housing 20 directly to the bulkhead 14.

The upper housing 18 has a central passage 26 opening into a cavity 28, and the lower housing has three through openings 30, only one of which is shown.

A hollow supply shaft 32 is shown located in the upper portion of the passage 26 and is secured in position by a set screw 34.

A sealing plate 36 having a boss 38 is positioned in the upper housing 18 so that the boss 38 is located at the lower end of the central passage 26 and one face of 36A of the sealing plate can contact a wall 28A of the cavity 28.

A primary non-return valve 40 is located in a central through passage 42 in the sealing plate and boss 36, 38. The boss 38 is provided with a number of vertical drillings 44 which communicate with ports 46 in the wall of boss. The upper surface 36A of the sealing plate 36 is provided with a sealing ring 48 to make sealing contact with the wall 28A of the cavity 28.

A spring 50 is located between the sealing plate 28 and a secondary valve housing 52 which is located in the cavity 28. Three secondary non-return valves 54, only one of which is shown, are each located in one of the through openings 30. Each valve 54 has a fluted operating pin 56 located in an opening 58 in a housing 52.

The upper end of each valve 54 is located in a space 60 in the housing 50 and a port 62 is provided in the wall of the housing 52 in communication with the space 60. Three locating pins 64, only one of which is shown, are provided to prevent rotation between the sealing plate 36 and the housing 52.

The housing 18 is provided with an opening 66 to enable a pressure transducer (not shown) to be attached so as to indicate the pressure within the cavity 28.

Similarly each through opening 30 in the lower housing 20 has a drilling 68 communicating with an opening 70 enabling a pressure transducer 71 to be attached and to monitor the pressure in each through opening 30.

A sleeve comprising a fixed portion 72 and a moveable portion 74 is located in the central passage 26 of the housing 18. The upper fixed sleeve has a number of equi-spaced passages 76 and the moveable sleeve 74 has a number of similar equi-spaced passages 78. The upper sleeve 72 has a central through passage 80 which is aligned with a corresponding passage 82 in the lower sleeve 74, the lower end of the passage 82 being of smaller diameter 82A than the upper end of the passage.

The movable sleeve has a cylindrical extension 84 which contacts the upper surface of the boss 38 and surrounds the upper portion of the nonreturn valve 40.

The housing 52 and the lower housing 20 have pilot holes 100 which provide an emergency arrangement should the non-return valves fail. In order to release pressure, a pathway is drilled through the primary non-return valve, destroying this valve and then through the pilot holes 100 to join the drillings 68.

In order to use the valve apparatus 12 the apparatus is attached to the bulkhead 14 of the pipeline plug apparatus 2 which is positioned in the pipeline 4 as illustrated in Fig. 1. Pipelines 88, 86 and 90 are each attached between one of the openings 30 and one of the inflatable gripping tyres 6 and one of the inflatable sealing tyres 8 of the plug system. A pressurising medium such as water or hydraulic fluid is pumped through the hollow shaft 32 under pressure and passes through the internal passage 80 , through the primary non-return valve 40 into the cavity 28 and through the three secondary non- return valves 54 via the passages 62 and into the inflatable tyres 6, 8 through the openings 30 and pipelines 86, 88 and 90, to inflate all of the tyres 6, 8. The tyres 6, 8 are pressurised to a predetermined pressure and then the pressure in the shaft 32 is vented to ambient pressure.The pressure in each of the pipelines 86, 88 and 90 is monitored via the pressure transducers 71 as is the pressure in the cavity 28. All of these pressures are monitored to ensure that the pre-determined pressures are not falling and that the primary non-return valve 40 is functioning correctly.

The proper functioning of the secondary non-return valves 54 and the primary non-return valve 40 can be checked by reducing the pressure in the cavity 28.

Referring particulary to Fig. 3, the pressure in the cavity 28 is reduced by opening the primary non-return valve 40. A bleed rod 92 which has a reduced diameter end 94 is inserted in the hollow shaft 32 so that the end 94 lines up with a release pin (not shown) in the upper end of the valve 40 as illustrated in Fig. 3. When the rod 92 is pushed inwardly in the direction of arrows A, the primary valve will be depressed against the spring load 50 so as to open the valve 40 but a sealing contact is still maintained between the sealing plate 36 and wall 28A of the cavity 28. The pressurised medium in the cavity 28 will then flow into the hollow shaft 32 around the rod 92 via the valve 40. The pressure in the cavity is monitored using the pressure transducer until a predetermined pressure is reached. The bleed rod 92 is then removed and the valve 40 will close automatically.

Although the sealing plate 36 is shown displaced from the wall 28A of the cavity 28 in Fig. 3, the sealing plate remains in contact with the wall 28A throughout the pressure reducing operation, as shown in Fig. 2.

The moveable sleeve 74 into which the end of the bleed rod 92 is inserted is provided with a shoulder and the length of the end 94 is chosen to prevent the valve and therefore the sealing plate 36 from being depressed too far against the load of the spring 50, otherwise the secondary non-return valves could be depressed releasing the pressurised medium through drillings 44 and ports 46 in the boss 48. The movable sleeve 74 cannot be moved axially in the housing 18 by the operation of the bleed rod 92 as the sleeve 74 is screwed into position within the housing 18.

Once the pressure in the cavity 28 has reached the desired level, the pressure in the cavity 28 is monitored by means of the cavity pressure transducer. If the pressure in the cavity 28 starts to increase this would indicate a leak in one or more of the secondary valves 54.

Similarly if the pressure in the cavity 28 starts to reduce this would indicate a leak in the primary non-return valve 40.

As there is a differential pressure between the cavity 28 and each pipeline 86, 88 and 90 each system can be monitored using its respective pressure transducer 71 and the pressure transducer of the cavity 28 to ensure correct functioning.

Assuming both the primary and all of the secondary valves are functioning correctly, the pressure in the cavity 28 and the pressure in each pipeline 86, 88 and 90 are monitored at regular intervals to ensure that the respective pressures are being maintained.

In order to de-energise the tyres 6, 8 in the plug apparatus 2, firstly any pressure in the cavity 28 is released using rod 92 as previously described. A release rod 96 (Fig. 4) is then inserted through the hollow shaft 32. The lower end of the release rod has a threaded portion 98 which engages with an internal thread in the lower sleeve 74. The release rod 96 is rotated so that the lower sleeve 74 is turned and moves downwardly in a housing 18 and the extension 84 of the lower sleeve engages the upper end of the boss 38 and moves the boss and therefore the sealing plate 38 against the load of the spring 50. The lower face of the sealing plate depresses each of the fluted pins 56 in the housing 52 and will open each of the secondary non- return valves 54 simultaneously.

The pressurising medium in each of the pipelines 86, 88 and 90 will therefore pass through their respective secondary non-return valves and through the ports 62 into the cavity 28. The pressurising medium will then flow through the ports 46 and drillings 44 in the boss 38 bypassing the non-return valve 40. The pressuring medium then flows into the hollow shaft 32 around the release rod via the drillings 78 and 76 in the sleeving 72, 74.

It will be noted that the valve apparatus 12 allows operation of the primary non-return valve and the secondary non-return valve independently of one another in order to release the pressurised medium from the valve apparatus and from the pressurised apparatus.

In order to release pressure from the valve apparatus 12, only the primary non-return valve has to be opened, but when releasing pressure from a pressurised apparatus, the pressure in the valve apparatus 12 must first be released, and then the secondary non-return valves can be released to release the pressure in the pressurised apparatus.

The bleed rod 92 and the release rod 96 can both be up to three or four metres in length. It will be appreciated therefore that the valve apparatus 12 can be located closely adjacent a pipeline plug apparatus and be operated remotely from that location.

The valve apparatus according to the present invention provides for maximum safety and also enables the non- return valves in the valve apparatus to be checked for leakage and for the pressures to be monitored continuously.

Claims

1. A valve apparatus comprising a housing, a primary and at least one secondary non-return valve mounted in the housing, a sealable space in the housing between the primary non-return valve and the at least one secondary non-return valve, inlet ducting to allow a pressurising medium to flow into the housing through the primary and the at least one secondary non-return valve and sealable space to the apparatus to be pressurised, first outlet ducting to allow pressurised medium to flow from the sealable space through the primary non-return valve and out of the valve apparatus, second outlet ducting to allow pressuring medium to flow from the pressurised apparatus through the at least one secondary non-return valve into the sealable space and out of the valve apparatus by passing the primary non-return valve, the primary non-return valve being operable remotely from the valve apparatus to open the primary non-return valve and allow pressurised medium to escape from the sealable space through the primary non-return valve and the first outlet ducting, and the at least one secondary non-return valve being operable to open the at least one secondary non-return valve and allow pressurised medium to escape from the valve apparatus via the first and second outlet ducting.

2. A valve apparatus as claimed in claim 1 in which the sealable space comprises a cavity in the housing, one wall of which comprises a moveable sealing plate.

3. A valve apparatus as claimed in claim 2 in which the sealing plate has a opening extending through the plate, the primary non-return valve being located in. the opening.

4. A valve apparatus as claimed in claim 2 or claim 3 in which the sealing plate includes internal passages comprising the second outlet ducting.

5. A valve apparatus as claimed in claim 2, claim 3 or claim 4 in which the sealing plate includes sealing means to make a seal between the sealing plate and a wall of the cavity, the valve apparatus including spring means to urge the sealing plate into sealing contact with said cavity wall.

6. A valve apparatus as claimed in any one of claims 2 to 5 in which the at least one secondary non-return valve is located in a through opening in a further wall of the cavity, the at least one secondary non-return valve having operating means to open the at least one secondary non-return valve.

7. A valve apparatus as claimed in claim 6 having a secondary non return valve housing located in the cavity and including guide means for operating means of the at least one secondary non-return valve.

8. A valve apparatus as claimed in claim 7 in which the secondary valve housing has a passage providing communication between the sealable space and the at least one secondary non-return valve.

9. A valve apparatus as claimed in claim 6 or claim 7 in which locating means are provided between the secondary valve housing and the sealing plate.

10. A valve apparatus as claimed in claim 7 including sleeving located in the inlet ducting, the sleeving having an opening to allow access of a tool operable remotely from the valve apparatus to open the primary non-return valve and allow pressurised medium in the sealable space to be released from the valve apparatus via the primary non-return valve and the first outlet ducting.

11. A valve apparatus as claimed in claim 10 in which the sleeving includes through openings comprising the second outlet ducting.

12 A valve apparatus as claimed in claim 10 or claim 11 in which the sleeving comprises two portions, a first portion secured to the housing, and a second portion operable remotely from the valve apparatus to move the sealing plate against the load exerted by the spring means out of sealing engagement with the cavity wall, and to open the at least one secondary non-return valve to allow pressurised medium to flow through the at least one secondary non return valve into the sealable space, and to be released from the valve apparatus via the second outlet ducting.

13. A valve apparatus as claimed in any one of the preceding claims in which pressure indicating means are secured in communication with the sealable space.

14. A valve apparatus as claimed in any one of the preceding claims having pressure indicating means in communication with the through openings in the secondary non-return valve housing.

15. A valve housing as claimed in any one of the preceding claims including a plurality of secondary non-return valves.

16. A valve apparatus constructed and arranged for use of operation substantially as herein described and with reference to the accompanying drawings.