GB2548403A

GB2548403A - Removing and replacing an emergency control valve (ECV)

Info

Publication number: GB2548403A
Application number: GB1604623.7A
Authority: GB
Inventors: Trevor Hodgson Steven
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-03-17
Filing date: 2016-03-17
Publication date: 2017-09-20
Also published as: GB201604623D0

Abstract

An emergency control valve in a gas carrying pipe has two arms at an angle to each other, one connected to the gas meter inlet and the other connected to a service pipe 3. This valve is replaced by closing the valve and disconnecting the arm from the meter inlet, opening the valve, and then temporarily blocking the bore of the pipe. The bore is blocked by apparatus comprising an inflatable bag 15 which is pushed through the angled pipes. The apparatus also comprises means for deflecting the travel direction of the inflatable bag 15, and a connection 16 between the bag 15 and an air supply to inflate the bag 15. Once the bore is blocked, the first arm of the valve is released from the service pipe 3 and the faulty valve is replaced. The arms are then reconnected, with the temporary block on the bore removed to allow gas to flow, and the first arm of the replacement valve is then reconnected to the meter inlet pipe. The deflecting means can be a curved member, such as a ball, and can be at the leading edge of the bag and the trailing edge.

Description

Title

Removing and replacinB an Emersencv Control Valve fECV)

An emergency control valve (ECV) is used in a property such as a dwelling or building to control the supply of combustible gas to the property. It is normally positioned between the supply or service pipe and the gas meter so that when there is an emergency such as a gas leak the valve can be closed to prevent gas escaping into the property.

After a prolonged period of use the valve can wear out, become faulty and leak or can just be part of a scheduled replacement program. Consequently ECVs are changed on a fairly regular basis to mitigate this possibility.

The ECV inlet is connected to the service pipe and the outlet of the ECV can be inline with the gas meter inlet or at varying angles to the gas meter inlet and is connected to the gas meter via additional piping.

Inline ECVs can be replaced in live conditions by inserting a device which temporarily blocks the service pipe that prevents the flow of gas through the ECV. This usually takes the form of an inflatable bag.

At present the only way an ECV that is angled can be changed, is for the supply to be terminated prior to its removal.

Currently the existing valve is turned off and the additional piping to the meter is removed from the outlet of the ECV.

The blocking device is connected to the outlet of the angled ECV, the valve is opened and the pipe is temporarily blocked by operating the device that allows an inflatable bag to be inserted through the now accessible valve outlet and into the gas meter inlet.

The bag is inflated using the appropriate media to temporarily block the bore of the supply pipe thus allowing the existing valve to be removed. Then after the existing valve has been removed and the replacement valve is connected to the supply pipe, the bag is deflated to remove the blockage and the bag is removed. The valve is then closed and reconnection of the existing pipe work is made.

Most ECVs are of the straight through type where the inlet and outlet are aligned. However in a large number of cases the ECV is not of the straight through type but the inlet and outlet are at an angle to each other usually at a right angle to each other. In this case it is extremely difficult if not impossible to push the inflatable bag from the valve outlet into the valve inlet and into the meter inlet pipe around the bend in the valve.

It is therefore one object of the present invention to provide apparatus comprising an inflatable bag which can be pushed around the bend in the valve.

It is another object of the present invention to provide a method for replacing an emergency control valve (ECV) with a replacement valve.

According to one aspect of the present irvvention, there is provided apparatus for temporarily blocking fluid flow through the bore of a pipe, the apparatus comprising an inflatable bag which when inflated in situ in the bore of the pipe can temporarily block the bore of the pipe to fluid flow, the bag, in use, being pushed from one part of the pipe into and then into another part of the pipe which is at an angle to the one part of the pipe, there being means for deflecting the direction of travel of the bag from the one part of the pipe to the other part of the pipe around a bend and means for connecting the bag to an air supply to inflate the bag in situ in the pipe.

Preferably the pipes form part of an emergency control valve which is provided with a handle which can be moved to open and close the valve.

Suitably the apparatus comprises a curved member at a leading end of the bag for engaging with the deflecting means whereby the bag can be pushed around the bend in the valve.

Conveniently the apparatus comprises a curved member at the trailir^ end of the bag.

Preferably the curved member is a ball.

Suitably there is arv air line connected to the bag to inflate the bag.

Conveniently, in use, the bag is launched into the other part of the pipe by means of a launch tube which incorporates the deflecting means.

According to another aspect of the present invention, there is provided a method for replacing an emergency control valve (ECV) with a replacement valve in a gas carrying pipe in which the valve is located between a gas carrying service pipe and a gas meter inlet pipe, the valve having two arms at an angle to each other with a first arm releasably connected to the gas meter inlet pipe and the second arm releasably connected to the service pipe, the method comprising closing the valve, disconnecting the first arm of the valve from the gas meter inlet, opening the valve, temporarily blocking the bore of the service pipe to prevent the flow of gas from the service pipe, releasing the first arm of the valve from the service pipe, removing the defective valve, releasably connecting the second arm of a replacement valve to the service pipe, removing the temporary blocking of the bore of the service pipe to allow gas to flow into the meter and reconnecting the first arm of the valve to the gas meter inlet pipe.

An embodiment of the invention will now be particularly described with reference to the accompanying drawings in which:

Figure 1 is a view from the side of an emergency control valve (ECV),

Figure 2 ie a side view in perspective of a back clamp ar\d headworks, the back damp being for clamping the headworks to the outlet of the ECV and the headworks housing an insertion tube for the flexible bag together with a launch tube for the insertion tube.

Figure 3 is a side view in perspective of the flexible bag now extending through the insertion tube, the bag being connected to a flexible tube for supplying air to the bag.

Figure 4 is a side view of the headworks with the headworks broken away and with the insertion tube and the bag pulled back into the launch tube.

Figure 5 is a side view in perspective of the headworks tilted at an angle to the inlet of the ECV,

Figure & is a side view of the headworks clamped to the outlet of the ECV to form a seal,^

Figure 7 is a side view In section of the launch tube pushed forward into the outlet of the ECV,

Figure 8 is a side view in section of the headworks with the bag now having been pushed through the inlet of the ECV and into the gas service pipe after having circumvented the bend in the ECV,

Figure 9 is a schematic side view of the flexible air supply tube for the bag corvrvected to a pump to provide a source of air pressure by way of a gauge for controlling the pressure of the air.

Figure 10 is a side view of the apparatus with the pump removed, the flexible tube being folded and clamped with a holding clamp to ensure the bag remains inflated.

Figure 11 is a side view of the apparatus similar to Figure 10 with the pump removed and the insertion tube withdrawn.

Figure 12 is a side view in perspective of the ECV in position to be unscrewed from the inlet pipe after the removal of the headworks and the clamp with the bag still inflated.

Figure 13 is a schematic side view of the ECV,^ the clamp and head works being disengaged but the headworks still located on the flexible tube which is passed through its bore, the flexible tube being folded and clamped by a holding clamp between the gas inlet pipe and the ECV,

Figure 14 is a view similar to Figure 13 in which the first holding clamp has been released and the headworks and the old ECV removed over and off the end of the flexible tube, a new ECV and the headworks then refitted back onto the flexible tube.

Figure 15 is similar to figure 14 with the pump and gauge attached again to the end of the flexible tube and air is pumped to re-pressurise the tube, the tube being then folded between the pump and the headworks and reclamped and the new ECV is slid up the flexible tube followed by the headworks and the second holding clamp is then removed,

Figure 16 is similar to Figure 15 and shows the apparatus arrangement prior to the second holding clamp being removed,

Figure 17 is a schematic view of the new ECV screwed into position on the service pipe showing the flexible bag apparatus in situ in the inlet pipe,

Figure 18 is a schematic view of the ECV in position on the gas inlet pipe with the headworks attached to the valve by means of the back clamp to create a seal.

Figure 19 shows a perspective view In section of the ECV and the headworks in which the the launch and insertion tubes have been pushed into the new ECV until locked in position, the holding clamp being removed from the flexible tube.

Figure 20 shows a perspective view of the new ECV in section connected to the service pipe with the bag deflated to remove the temporary blockage to the bore of the gas inlet pipe.

Figure 21 is similar to Figure 20 with the now deflated bag pulled back out from the service pipe until it touches the end of the insertion tube.

Figure 22 is similar to Figure 21 with the ECV closed to prevent gas flow to the ECV outlet, the nuts being then slackened to remove the entire apparatus from the ECV,

Figure 21is a sectional view of the new ECV,

Referring to the drawings, in Figure 1 an emergency control valve (ECV) 1 is shown comprising a normally vertical arm 2 which is releasably connected by means of a thread to vertical service or gas supply pipe 3 and a normally horizontal arm 4 which is usually connected to the inlet of the gas meter (not shown). The arms 2 and 4 are at right angles to each other. In this Figure the pipework (not shown) from the arm 4 of the ECV 1 to the gas meter inlet (not shown) is removed so that the pipe bore blocking apparatus (not shown) can gain access to the ECV 1. In Figure 1 the ECV valve is closed by a manually operable handle lA before the pipework is removed to prevent the escape of gas through the arm 4 into the property.

In Figures 2 to 5, there is shown a back clamp 5 and a headworks 6, the headworks 6 providing means by which the pipe blocking apparatus can be introduced into the ECV 1.

The back clamp 5 is a generally a part cylindrical hollow member 7 with a part circular back plate 8 to engage the vertical arm 2 of the ECV 1 in order to clamp the headworks 6 to the horizontal arm 4 of the ECVl. In use the back clamp hollow member 7 is positioned over the outermost surface of the external bend in the ECVl where it overlies the horizontal arm 4 as shown most clearly in Figure 5 with the back plate 8 engaging the vertical arm 2 of the ECV 1. The back clamp 5 has a pair of spaced bolts 9 which are each connectable to the headworks 6. The bolts 9 are each pivotally connected to the back clamp7 and extend through apertures 10 in the body of the headworks 6. The bolts 9 have threaded ends whereby they can be attached by nuts 11 to the body of the headworks 6 as shown more clearly in Figure 5. Tightening of the nuts 11 causes the headworks 6 to engage with and form a seal with the horizontal arm 4 of the ECV1. In use, extending through a bore in the headworks 6 is a launch tube 12 for inserting the inflatable bag apparatus 13 into the ECV L· The launch tube 12 terminates at its forward end in an angled deflector member 12A positioned to deflect the apparatus into the service pipe 3. There is a further tube 14 located within the launch tube 12 into which the inflatable bag apparatus 13 is inserted.

The apparatus 13 comprises the bag 15 which is inflatable by a flexible plastic air line tube 16 which is connected to the rear of the bag 15, the bag being of a flexible rubber material. At the leading end of the bag 15 there is provided a cylindrical member 17 with a hemispherical end 18 and there is also a ball 19 at the trailing end of the bag 15. There is a central aperture through the ball 19 through which the inflation tube 16 passes to the bag 15. In combination the member 17 and the hemispherical end 18 enable the bag 15 to be pushed through the horizontal arm 4 of the ECV 1 and then after deflection by the deflector member 12 A around the bend into the vertical arm 2 of the ECV 1 and into the service pipe 3.

Referring to Figure 4 initially the launch tube 12 is pulled fully back with the bag 15 into the headworks 6. A gland nut 20 on the insertion tube 14 is tightened to compress the inflation tube 16 and hold the bag 15 in position. The headworks 6 is provided with a ratchet arm 21 which locks the launch tube 12 in position. This arm 21 is pulled down to release the launch tube 12 and the launch tube 12 is pulled back to a stop (not shown).

Referring to Figure 5 the back clamp 5 is attached to the ECV 1 and then the back clamp 5 is connected to the headworks 6. The headworks 6 are swung onto the ECV 1, the two nuts 11 are tightened on the clamp bolts 9 to secure the headworks 6 to the horizontal arm 4 to create a seal with the ECV 1. A vent valve 22 on the headworks 6 in combination with a manoflex gauge (not shown) is used to verify there is a gas tight connection by turning the vent valve screw to the open position and then closing the valve 22.

Referring to Figure 6 the ECV 1 valve is now opened and the launch tube 12 is pushed forward into the ECV 1 and locked into position with the ratchet arm 21.

Referring to Figures 7 and 8 the inflatable bag 15 is pushed into the horizontal arm 4 of the ECV 1 around the bend in the ECV 1, into the vertical arm 2 of the ECV 1 and finally well into the service pipe 3 at least up to a black mark (not shown) on the flexible tube 16. In addition the insertion tube 14 is aiso pushed fuily forward.

Referring to Figure 9 an air pump 23 and gauge 24 is attached to the flexible tube 16 by being locked in position. The bag 15 is then inflated by air pressure from the pump 23 to 2 bar to temporarily block the bore of the service pipe 3 as shown in outline in figure 10.

Referring to Figure 10 the flexible air line 16 is then folded between the headworks 6 and the air pump 23 and clamped by a first holding clamp 25 to ensure that the bag 15 remains inflated.

Ifi Figures 11 and 12 the pump 23 is removed from the air line tube 16, The gas pressure is then purged from the ECV1 by turning the vent valve screw 22 on the body of the headworks 6 to the open position then closing the valve 22. The flexible bag 15 is shown infiated within the service pipe 3 with the air iine 16 extending from the ECV 1 (Figure 12), The ratchet arm 21 has been pulled down to release it and the launch tube 12 and insertion tube 14 are both pulled back until they reach their respective stops (not shown).

The nuts 11 on the bolts 9 are then slackened to release the back clamp 5 from the ECV 1 and the clamp 5 and headworks 6 are swung away from the ECV 1 (not shown). The vertical arm 2 of the ECV 1 is then carefully unscrewed from the service pipe 3 and is slid up the flexibie air tube 16 to assume the position shown in Figure 13,

The air tube 16 is then folded near the ECV 1 (approximately 50mm from the ECV 1) and clamped with a further second hoiding clamp 26 to maintain the bag 15 inflated. Then the first holding clamp 25 is removed and the back clamp 5, the headworks 6 and the existing ECV 1 are slid off the tube 16. The new replacement ECV 27 together with the back clamp 5 and the headworks 6 are then slid back onto the flexible air tube 16 as shown in Figure 14,

The air pump 23 is then re-attached to end of the flexible air tube 16 as shown in Figure 15 and the tube 16 is then pressurised to 2 bar (150mm) by the pump 23. The tube 16 is then folded again between headworks 6 and the pump 23 and reclamped with the holding clamp 25 as shown in Figure 15 to maintain the bag 15 inflated. Then the pump 23 is removed from the end of the tube 16 as shown in Figure 16,

The holding clamp 26 is removed and then the new ECV 27 is then slid along the tube 16 and is screwed onto the service pipe 3 as shown in Figure 17.

The back clamp 5 and the headworks 6 are then slid along the tube 16 and the back clamp 5 and headworks 6 are swung over the ECV 27 with the hollow cylindrical member 7 of the back clamp 5 overlapping the horizontal arm 4 of the ECV 27 with the clamp back plate 8 engaging the vertical arm 2 of the ECV 27. The two bolts 9 are pushed through the apertures 19 in the headworks 6 and the nuts 11 are attached to the ends of the bolts 9 and are lightly tightened to form a seal with the horizontal arm of the ECV 27 as shown in Figures 18 and 19.

In Figure 20 the launch tube 12 and the insertion tube 14 are pushed into the new ECV 27 until they are locked in position. The bag 15 is then deflated by removing the holding clamp 25 and the flexible tube 16 is pulled back until it touches the end of the insertion tube 14.

To position the bag 15 in the headworks 6 both the flexibie tube 16 and the insertion tube 14 are pulled back together until a stop 28 on the circumference of the insertion tube 14 is aligned with a stop 29 for the launch tube 12. Then with the ratchet arm 21 held down to release the launch tube 12 the launch tube 12 is pulled back to its stop position 29 as shown in Figure 21. The new ECV 27 is then closed by the handle lA. The nuts 11 on the bolts 9 are then slackened to release the back clamp 5 from the ECV 27 and the clamp 5 and headworks 6 are swung away from the ECV 27. The pipework (not shown) is then reinstated between the ECV 27 and the gas meter (not shown). Then the handle lA on the ECV 27 is rotated to open the valve and allow the gas to enter the gas meter from the service pipe 3.

Claims

Ciaims

1. Apparatus for temporarily blocking fluid flow through the bore of a pipe, the apparatus comprising an inflatable bag which when inflated in situ in the bore of the pipe can temporarily block the bore of the pipe to fluid flow, the bag, in use, being pushed from one part of the pipe into and then into another part of the pipe which is at an angle to the one part of the pipe, there being means for deflecting the direction of travel of the bag from the one part of the pipe to the other part of the pipe around a bend and means for connecting the bag to an air supply to inflate the bag in situ in the pipe.
2. Apparatus as claimed in claim 1 in which the pipes form part of an emergency control valve which is provided with a handle which can be moved to open and close the valve.
3. Apparatus as claimed in claim 1 or claim 2 in which the apparatus comprises a curved member at a leading end of the bag for engaging with the deflecting means whereby the bag can be pushed around the bend in the valve.
4. Apparatus as claimed in ciaim 3 in which the apparatus comprises a curved member at the trailing end of the bag.
5. Apparatus as claimed in claim 4 in which the curved member is a ball.
6. Apparatus as claimed in any of the preceding claims in which there is an air iine connected to the bag to inflate the bag.
7. Apparatus as claimed in any of the preceding claims in which, in use, the bag is launched into the other part of the pipe by means of a launch tube which incorporates the deflecting means. 8r A method for replacing an emergency control valve (ECV) with a replacement valve in e gas carrying pipe in which the valve is located between a gas carrying service pipe and a gas meter inlet pipe, the valve having two arms at an angle to each other with a first arm releasably connected to the gas meter inlet pipe and the second arm releasably connected to the service pipe, the method comprising closing the valve, disconnecting the first arm of the Valve from the gas meter inlet, opening the vaive, temporarily blocking the bore of the service pipe to prevent the flow of gas from the service pipe, releasing the first arm of the valve from the service pipe, removing the defective valve, releasably connecting the second arm of a replacement valve to the service pipe, removing the temporary blocking of the bore of the service pipe to allow gas to flow into the meter and reconnecting the first arm of the valve to the gas meter inlet pipe.
9. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.
10. A method substantially as hereinbefore described with reference to the accompanying drawings.