GB2465310A

GB2465310A - Valve insertion

Info

Publication number: GB2465310A
Application number: GB1002956A
Authority: GB
Inventors: Kevin Dobbs
Original assignee: Balfour Beatty PLC
Current assignee: Balfour Beatty PLC
Priority date: 2010-02-22
Filing date: 2010-02-22
Publication date: 2010-05-19
Anticipated expiration: 2030-02-22
Also published as: GB201002956D0; GB2465310B

Abstract

A method of installing a valve into a pipe run 10 comprises clamping a valve housing 12, 14 around the pipe, the valve housing defining a T-junction of three openings, the first 16 and second 18 of which surround the pipe. A section of the pipe is removed by drilling using the third opening 20 as guide, such that two end faces of the pipe are defined with a portion of the pipe removed between them having a cylindrical envelope. Valve body and valve drive mechanisms are then inserted into the third opening 20. The third opening is then closed with a valve top plate that includes a valve drive actuator for operating the valve drive mechanism.

Description

VALVE INSERTION

This invention relates to the insertion of a valve into an existing pipe run, and in particular while there is live flow in the pipe.

The desire to make modifications to a pipe network while maintaining flow in the pipes is well known. In the mains water network in particular, it is desirable to keep disruption to the end user as brief as possible, and if possible to avoid any such disruption.

This invention relates to the insertion of a valve into a pipe run, for example a mains water pipe.

The current method for this operation, in a way which avoids any disruption to the user, involves five excavations. Firstly, an excavation is made at each side of the location at which the valve is to be fitted. A bypass pipe is then installed between these locations by a drill and tap operation for tapping into the pipe to form two 1-junctions. The first two excavations may be around 14m apart.

Two further excavations are made closer to the location for the valve, for example about 8m apart. The flow is interrupted at these locations by inserting a line stopping element.

The final excavation is then at the desired location, and the pipe can be worked on with no water flow present, for example by cutting out a section of pipe and fitting a valve in place of the removed pipework.

The flow is then restored and the temporary bypass removed, with the branch of each of the T-junctions shut off.

It will be immediately apparent that this process is costly and time consuming.

There is therefore a need for an improved process for installing a valve in a pipe run carrying a flow of fluid.

According to the invention, there is provided a method of installing a valve into a pipe run, comprising: clamping a valve housing around the pipe, the valve housing defining a T-junction of three openings, the first and second of which surround the pipe; removing a section of the pipe by drilling using the third opening as guide, such that two end faces of the pipe are defined with a portion of the pipe removed between them having a cylindrical envelope; inserting a valve body and valve drive mechanism into the third opening; closing the third opening with a valve top plate that includes a valve drive actuator for operating the valve drive mechanism.

This method completely removes a portion of the pipe. The valve body preferably has a cylindrical outer shape so that it mates with the cut (drilled) end faces of the pipe run. Within the valve body, a rotary valve member can then be fitted. This process involves only a single excavation at the location of the valve (for example 3m long), and only requires the original pipe to be worked on at a single location.

A temporary valve can be fitted over the third opening before removing a section of the pipe. This temporary valve can be used to prevent fluid escape from the pipe while the different operations are carried out. The drill can define a sealed chamber so that when drilling (with the temporary valve opened) fluid flow in the pipe can be maintained. The temporary valve can be part of the drill.

Removing a section of the pipe by drilling thus preferably comprises fitting a drill unit to the third opening, which drill unit includes the temporary valve, and drilling out a dowel of the pipe using an annular drill. The valve body preferably comprises a cylinder with a lateral passageway for alignment with the first and second openings.

The valve drive mechanism can comprise a rotary butterfly valve.

Clamping the valve housing around the pipe can comprise coupling a two-part housing together around the pipe. A lower part of the valve housing can be cast in concrete to prevent movement.

The invention also provides a pipe run, comprising: a pipe; a valve along the pipe, the valve comprising: a valve housing clamped around the pipe, the valve housing defining a T-junction of three openings, the first and second of which surround the pipe; a valve body and valve drive mechanism within the third opening, the valve body in contact with opposing end faces of the pipe at a removed section of the pipe; a valve top plate that includes a valve drive actuator for operating the valve drive mechanism, sealing the third opening.

The invention also provides valve installation equipment, comprising: a multi-part valve housing for mounting around a pipe, the valve housing defining a T-junction of three openings, the first and second of which are coaxial for surrounding a pipe in which the valve is to be installed; a drill for removing a section of the pipe by drilling using the third opening as guide; a valve body and valve drive mechanism for insertion into the third opening; a valve top plate that includes a valve drive actuator for operating the valve drive mechanism.

An example of the invention will now be described in detail with reference to the accompanying drawings, in which: Figures 1 to 6 show sequential steps in the installation method of the invention; Figure 7 shows the inserted valve in a pipe run.

The invention provides a method of installing a valve into a pipe run in which a T-junction valve housing is clamped around the pipe. A section of the pipe is removed by drilling using the T-junction opening, such that two end faces of the pipe are defined with a portion of the pipe removed between them having a cylindrical envelope. A valve body and valve drive mechanism is fitted through the T-junction opening and it is then closed and sealed with a valve top plate.

Figure 1 show a pipe 10 along which a valve is to be fitted. In one example, the pipe is a mains water pipe, carrying a live water flow.

The first step of Figure 1 comprises fitting a two-piece valve housing 12,14 around the pipe. The valve housing has an upper portion 12 and a lower portion 14 which are bolted together around the pipe. The valve housing defines a T-junction of three openings, the first 16 and second 18 of which surround the pipe and are coaxial. The third opening 20 forms a perpendicular T-junction.

Seals are formed at the first and second openings 16,18, using seal rings 22,24 which are compressed against or into the gap between the openings 16,18 and the pipe by compression plates 26,28.

The top part 12 of the valve housing has ports 30 which allow the pressure on each side of the valve housing to be equalized, so that the valve member (shown and described below) can easily be turned.

Figure 2 shows the components of Figure 1 after assembly, and also shows an annular drill bit 32.

After the components are assembled, the housing is preferably cast in concrete to provide a stable footing, so that when the valve is closed, the forces acting on the valve do not move the valve housing.

The drill bit is sized to be a snug fit within the third opening 20. The drilling machine used to drive the drill bit has an enclosed casing, and is arranged to be bolted to a flange 34 at the top of the opening 20.

The flange has two rings of openings, and a seal is eventually provided by the valve mechanism between the two rings. The inner ring comprises tapped bores that extend through the flange. Bleed nipples are screwed into the tapped openings underneath the flange, so that the inner openings are sealed off, and do not present a leakage path from the inside of the valve housing to the outside.

The inner circle of openings is used to mount the valve to the valve housing, and the outer circle of openings is used to mount the drilling machine.

The drilling machine defines an enclosure. Part of the drilling machine is a hydraulically operated sandwich valve located a small distance above the flange 34, in particular above the top of the completed valve.

When drilling the pipe with the sandwich valve open, the escape of water from the mains is contained, and escape through the inner ring of openings is prevented by the bleed nipples. After the drilling and withdrawal of the drill bit, the sandwich valve is closed so that the drill bit can changed.

Figure 3 shows the dowel of pipe 36 that is removed by the annular drill bit. The figure shows the shape schematically. The drilling defines opposing end faces of the pipe 38,40 at the removed section of the pipe.

Figures 4 to 6 show the valve components separately. However, in practice they are installed as one assembled unit.

Figure 4 shows a cylindrical valve body with a lateral passageway for alignment with the pipe ends. The valve body has a top flange with two concentric circles of openings. The inner circle is for receiving bolts of a top cap (Figure 6) and the outer circle carries bolts (not shown) which project down into the inner circle of openings of the flange 36 beneath.

Figure 5 shows a valve drive mechanism 42 in the form of a rotary butterfly valve.

Circular seals 44,46 are provided above and below the valve plate 48, and these seals engage with the inner surface of the valve body 40, above and below the lateral opening.

Figure 6 shows a valve top plate 50 that includes a valve drive actuator 52 for operating the valve drive mechanism, sealing the third opening. The top plate is bolted down to the valve body. The drive actuator can rotate the valve through a cog mechanism linking the actuator 52 to the central shaft of the butterfly valve.

The valve body, mechanism and cap are provided as a single unit. To insert them into the third opening 20, the drill bit of the drilling machine is changed to a ram for pushing the assembled valve components into place. Bolts of the assembled valve components are pushed into the inner circle of openings flange 36. The underside of the top flange of the valve body carries an annular seal which will locate between the circles of openings of the flange 36.

With the assembled valve components held in place by the ram, the bleed nipples are opened and replaced with fastenings sequentially, to gradually release pressure from the valve housing, and secure the valve mechanism in place.

After the valve mechanism has been secured, the drilling machine can be removed.

The completed valve is shown in Figure 7.

This method completely removes a portion of the pipe to enable a rotary valve to be completely across the path of the original pipe. The method can be performed without disrupting the flow.

The invention provides the method described above, as well as the installed valve (shown in Figure 6 once the top plate has been screwed down) as well as the installation equipment and valve components needed to make the installation.

Only one example has been described in detail. However many alternatives are possible.

For example the butterfly valve is only one example of rotary valve that can be used. The invention can be used in pipe runs carrying water or other fluids such as oil or cooling fluids.

The valve components will obviously be sized for the particular pipe being worked on, and this may be a metal or plastic pipe.

The drilling machine has not been described in detail, as it is of known construction, already used for live tapping operations, and other under pressure drilling operations. Similarly, the sandwich valve will be of known construction, in the form of a hydraulically operated sliding valve vane which opens or closes an orifice.

Various modifications will be apparent to those skilled in the art.

Claims

CLAIMS1. A method of installing a valve into a pipe run, comprising: clamping a valve housing around the pipe, the valve housing defining a T-junction of three openings, the first and second of which surround the pipe; removing a section of the pipe by drilling using the third opening as guide, such that two end faces of the pipe are defined with a portion of the pipe removed between them having a cylindrical envelope; inserting a valve body and valve drive mechanism into the third opening; closing the third opening with a valve top plate that includes a valve drive actuator for operating the valve drive mechanism.
2. A method as claimed in claim 1, further comprising fitting a temporary valve over the third opening before removing a section of the pipe.
3. A method as claimed in claim 2, wherein removing a section of the pipe by drilling comprises fitting a drill unit to the third opening, which drill unit includes the temporary valve, and drilling out a dowel of the pipe using an annular drill.
4. A method as claimed in any preceding claim, wherein the valve body comprises a cylinder with a lateral passageway for alignment with the first and second openings.
5. A method as claimed in any preceding claim, wherein the valve drive mechanism comprises a rotary butterfly valve.
6. A method as claimed in any preceding claim, wherein clamping the valve housing around the pipe comprises coupling a two-part housing together around the pipe.
7. A method as claimed in any preceding claim, further comprising casting a lower part of the valve housing in concrete to prevent movement.
8. A pipe run, comprising: a pipe; a valve along the pipe, the valve comprising: a valve housing clamped around the pipe, the valve housing defining a T-junction of three openings, the first and second of which surround the pipe; a valve body and valve drive mechanism within the third opening, the valve body in contact with opposing end faces of the pipe at a removed section of the pipe; a valve top plate that includes a valve drive actuator for operating the valve drive mechanism, closing the third opening.
9. A pipe run as claimed in claim 8, wherein the valve body comprises a cylinder with a lateral passageway aligned with the first and second openings.
10. A pipe run as claimed in claim 8 or 9, wherein the valve drive mechanism comprises a rotary butterfly valve.
11. A pipe run as claimed in any one of claims 8 to 10, wherein a lower part of the valve housing is cast in concrete to prevent movement.
12. Valve installation equipment, comprising: a multi-part valve housing for mounting around a pipe, the valve housing defining a T-junction of three openings, the first and second of which are coaxial for surrounding a pipe in which the valve is to be installed; a drill for removing a section of the pipe by drilling using the third opening as guide; a valve body and valve drive mechanism for insertion into the third opening; a valve top plate that includes a valve drive actuator for operating the valve drive mechanism.
13. Equipment as claimed in claim 12, further comprising a temporary valve for fitting over the third opening.
14. Equipment as claimed in claim 12 or 13, wherein the valve body comprises a cylinder with a lateral passageway for alignment with the first and second openings.
15. Equipment method as claimed in any one of claims 12 to 14, wherein the valve drive mechanism comprises a rotary butterfly valve.