Insert valve and method of insertion into pressurized pipelines

Abstract

A method of cutting and removing a section of prestressed concrete cylinder pipe and then installing a replacement valve while the pipeline is fully pressurized uses a replacement valve body (22) with two cylinders (223, 225) that match the openings of the cut pipe (35). Inside each of the two cylinders (223, 225) is a cut-covering assembly (62) which includes a cylindrical elastomeric seal (26) and spring tube (25), and a cross brace (27) extends between two surfaces within the spring tube (25). The replacement valve body (22) further includes a rotatable valve (24) in a central portion of the valve, and when the cylinder ends of the replacement valve body (22) are positioned adjacent the bores of cut pipe ends (36), the valve (24) can be rotated to push the elastomeric seals (26) of each of the cut-covering assemblies (62) into the bores of the cut pipe ends (36), thereby covering gaps (77) created when the pipe (35) was cut and placing the pipe ends (36) in fluid-tight engagement with the replacement valve body (22).

Claims

1. A replacement valve assembly 40, comprising: a valve body having a right side and a left side, the valve body comprising a right side cylinder, a left side cylinder, and a central chamber between the right side cylinder and the left side cylinder, wherein the central chamber, the right side cylinder, and the left side cylinder are disposed along a longitudinal axis and are in fluid communication so as to form a fluid passage between a right side cylindrical opening of the right side cylinder and a left side cylindrical opening of the left side cylinder, and wherein the central chamber comprises a rotatable valve; and a right side cut-covering assembly in an interior of the right side cylinder and a left side cut-covering assembly in an interior of the left side cylinder, wherein each cut-covering assembly comprises an elastomeric seal, a spring tube, and a first cross brace, wherein an exterior surface of the elastomeric seal contacts an interior surface of the cylinder, an interior surface of the elastomeric seal contacts an exterior surface of the spring tube, and the first cross brace extends within the fluid passage of the valve body between a first position on the interior surface of the spring tube and a second position on the interior surface of the spring tube, wherein when the rotatable valve is rotated between a first position and a second position, a first medial edge of the valve contacts the first cross brace of the right side cylinder and urges a right side end of the right side cut-covering assembly out of the right side cylindrical opening, and simultaneously a second medial edge of the valve contacts the first cross brace of the left side cylinder and urges a left side end of the left side cut-covering assembly out of the left side cylindrical opening.

2. The replacement valve assembly of claim 1, further comprising a second cross brace in each of the cut covering assemblies.

3. The replacement valve assembly of claim 1, wherein each of the cross braces comprises a medial flange, wherein the medial flange extends inwardly toward the central chamber.

4. The replacement valve assembly of claim 3, wherein the medial flange is a bent or curved bar that joins the cross brace at both ends of the bar.

5. The replacement valve assembly of claim 1, wherein the rotatable valve is a butterfly valve.

6. A method for replacing a valve in a pipe, comprising: placing a housing in fluid-tight engagement with the pipe on a right side and left side of the valve; cutting the pipe on the right side and left side of the valve, thereby creating a right side opening and a left side opening in the pipe; removing the valve through the housing; advancing a replacement valve assembly into the housing, wherein a cut-covering assembly is disposed within each pipe end of the replacement valve assembly, each cut-covering assembly comprising a cylindrical, elastomeric seal, a spring tube within the seal and a cross brace in the interior of the spring tube, the valve assembly further comprising a rotatable valve between the cut-covering assemblies; placing the pipe ends of the valve assembly into alignment with the right side opening and the left side opening of the pipe; and rotating the valve between a first position and a second position, wherein a first medial edge of the valve contacts a cross brace of a right side cut-covering assembly in a right side cylinder of the valve assembly and urges a right side end of the right side cut-covering assembly out of the right side cylinder, and simultaneously a second medial edge of the valve contacts a cross brace of a left side cut-covering assembly in a left side cylinder of the valve assembly and urges a left side end of the left side cut-covering assembly out of the left side cylinder, thereby pushing the cut-covering assemblies outwardly through pipe ends and into the cut ends of the pipe and placing the valve assembly into fluid-tight engagement with the cut ends of the pipe.

7. The method of claim 6, wherein the pipe is a prestressed concrete cylinder pipe (PCCP) having a concrete outer layer, an interior metal cylinder, and wire 1 wound around the metal cylinder, further comprising the steps of: placing a left side restraining clamp onto a left side of the pipe and a right side restraining clamp onto a right side of the pipe, thereby restraining pre-stressed tension wire on a right side and a left side of the pipe; placing a center restraining clamp on the pipe between the left side restraining clamp and the right side restraining clamp, thereby restraining pre-stressed tension wire in a center portion of the PCCP pipe, wherein the center restraining clamp comprises an upper mounting flange on an upper portion of the clamp; removing the concrete layer and the tension wire in the left medial portion of the pipe and in the right medial portion of the pipe, thereby exposing the interior metal cylinder in the left medial portion and the right medial portion; placing the housing around the center restraining clamp so that a left side opening of the housing surrounds the interior metal cylinder in a left medial portion of the pipe to the left of the center restraining clamp and a right side opening that surrounds the interior metal cylinder in a right medial portion of the pipe to the right of the center restraining clamp, wherein the housing is placed in fluid-tight engagement with the pipe.

8. The method of claim 6, further comprising the steps of attaching a service bonnet to an upper portion of the housing, wherein the upper portion of the housing comprises an upper opening to allow communication between the housing and the service bonnet, and wherein cutting the pipe comprises advancing a cutting tool from the bonnet through the upper opening and cutting the pipe in the left medial portion and right medial portion of the pipe, thereby separating a central portion of the pipe containing the center restraining clamp.

9. The method of claim 8, wherein a service valve is included between the housing and the service bonnet, and wherein the service valve is in communication with the upper opening of the housing.

10. The method of claim 6, wherein the left side opening of the housing and the right side opening of the housing each comprise an elastomeric material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side elevation view of existing pipeline with three restraining clamps attached, a first outside-restraining clamp, a center restraining clamp with a mounting plate and a second outside-restraining clamp. Once the clamps are installed around the pipeline's concrete exterior, the clamps retain the concrete coating that holds the tensioned wires in place. Only PCCP pipe requires restraining of tension wires to provide a smooth clear cylinder.

(2) FIG. 2 is a side elevation view that shows existing a PCCP pipeline with three restraining clamps in place. These clamps secure the tension wires by encircling the concrete coating under compression. The concrete coating is removed between the center restraining clamp and outside restraining clamps, exposing the tension wires.

(3) FIG. 3 is a side elevation view of a PCCP pipeline with three restraining clamps installed. The tension wires between the clamps are safely removed, exposing the smooth steel cylinder to provide safe areas where work can be performed. The tension wires are removed between the center restraining clamp and the outside restraining clamps, exposing smooth steel cylinder in two locations where work can be performed.

(4) FIG. 4 is a sectional side elevation view of a PCCP pipeline with three restraining clamps installed around the concrete coating to secure the tension wires, allowing areas of the steel cylinder to be exposed. The center clamp has a mounting attachment for the stabilizing member to connect. A pressure holding enclosure is mechanically installed on the existing pipeline. Using an enclosure with more than one part allows installation of this enclosure in fluid-tight arrangement onto a pressurized pipeline. The enclosure provides the means of attaching a service valve on top. This service valve allows various operations that are required to perform the insertion valve process.

(5) FIG. 5 is a side elevation view that shows the cutting mechanism that uses at least one drive wheel and one support wheel to move a flexible belt. The belt incorporates attached diamonds, carbides or other abrasive media to wear through pipelines such as PCCP that are concrete, or the belt can include cutting edges that are sharp to perform cutting for pipes such as plastic and iron. In one embodiment the belt can include edges similar to a chain saw. In a preferred method the mechanism has at least two cutting belts with at least two drive wheels to sever the pipe section with one movement. Some pipelines may require one cut to be performed at a time. This figure shows a gearbox that is driven by a shaft which extends outside of the bonnet so that a power unit can be used to turn the belts.

(6) FIG. 6 is a perspective view depicting a gear box that turns drive wheels that power the movement of the belt to cut the pipe. The belt is impregnated with diamonds or other cutting medium. A number of existing products using flexible cables and wire that cuts material can be used. This illustration shows how the cutting assembly can be arranged and used to turn two flexible belts. The belts are used to make perpendicular cuts through the pipe section so a section of pipe can be cut and removed from a pipeline after a section of pipe is severed.

(7) FIG. 7 is a sectional side elevation view that shows a bonnet attached to a service valve. The service valve is in the fully open position, allowing the stabilizing member to advance and retract when the service valve is in the open position. The bonnet shown is retaining the center clamp in position. There are brackets as part of the enclosure that support the proposed section of pipe to be cut, keeping it rigid between these brackets and the stabilizing member.

(8) The cutting mechanism is shown to be advancing toward the pipeline and retracted by means of a feed screw that can be operated by rotating two screw jacks, though a single jackscrew can be used. The cutting tool uses power drive heads that is shown to rotate two belts that have diamonds, cutting or abrasive medium attached. Two belts are shown to perform two simultaneous cuts at the same time to separate a pipe section. On various projects it may be required to make a single cut at a time but two are shown for simplicity. The cutting mechanism feed screw can also be used to operate the new valves isolator to the open or closed position.

(9) FIG. 8 is a sectional side elevation view of the configuration of FIG. 7 but showing the cutting tool having passed completely through the pipe, severing the intended pipe section and revealing the gap left by the cut. This creates two pipe ends of the existing pipe. The illustration also shows the enclosures brackets that have retained the cut section of pipe during the cutting process and the same brackets will position the new valve into a precise position when installed.

(10) FIG. 9 is a sectional side elevation view of the configuration of FIG. 7 that shows the bonnet and service valve of FIGS. 7 and 8 after severing the pipe. The center restraining clamp and pipe section are both removed together into the housing by retraction of the stabilizing member. This process provides an area where the new valve will be installed.

(11) In addition to the removal of the cut pipe and clamp, the cutting tool is removed from the enclosure into the bonnet and the service valve is closed. The bonnet as shown has been depressurized and removed from the enclosure.

(12) FIG. 10 is a sectional side elevation view of the configuration of FIG. 7 that shows the new valve with its attached pipe ends, each holding a cut-covering assembly and attached to the stabilizing member. The new valve is retracted into the housing of the bonnet by retraction of the stabilizing member. The bonnet is reattached onto the service valve so it can be fully opened to allow passing of the new valve into the position or existing gap left behind by the removal of the cut section of pipe.

(13) FIG. 11 is a sectional side elevation view of the configuration of FIG. 7 that shows the stabilizing member advanced and placing the new valve into a rigid position with the enclosure centering brackets. This rigid installation of the valve provides the valve's pipe ends to be inline with the existing pipes cut ends. The new valve is stabilized into a position to allow precise alignment of the new and existing pipe bores. This illustration shows the gap 77 between the existing pipe ends and the new valves pipe ends.

(14) FIG. 12 is a side elevation view that shows the new valve ends installed in direct alignment with the existing pipe ends. The cut-covering assemblies provide spring-loaded sealing members (25, 26) housed within the new valve ends, which are wide enough to remain in a portion of the new valve ends, cover the cut gap in the pipe, and enter into the existing pipe ends.

(15) FIG. 13 is a sectional view of the cut-covering assembly. The outside circle is a pipe wall, the hashed-marked area is the rubber or flexible compound seal, and the overlapping internal line is the spring-type cylinder that is rolled to provide exterior expansion and can be pulled together prior to being inserted into the new valve ends so it will naturally want to expand, creating a force on the sealing member to keep it along the pipe's interior in the new valve's pipe ends or the inside diameter of the existing pipeline.

(16) FIG. 14 is a sectional view showing an embodiment of the sealing portion of the cut-covering assembly and how the rubber could be held into position in relationship with the spring tube. The cut-covering assembly seal is covering the gap cut in the pipe, a portion of the existing pipe interior and a portion of new valve pipe interior. The gap is shown above the seal design and is covered continually around the whole diameter of the pipe to create a fluid-tight seal of the gap.

(17) FIG. 15 is a side sectional view that depicts the new valve ends being installed in direct alignment with the existing pipe ends. The new valve can be opened under pressure by using a rod that passes through the bonnet and is connected to the operating nut of the butterfly valve. A seal is provided on the bonnet to keep fluid from escaping.

(18) By turning the operating mechanism in the direction that opens the new valve, both cut-covering assemblies (one on each side of the new valve) are evenly pushed by direct engagement of the butterfly isolator.

(19) The natural movement when opened keeps the cut-covering assemblies evenly moved to a predetermined location. The isolator of a butterfly valve when opened uses a pivoting movement to rotate a disc, and as the disc rotates it increases in length into the new valves pipe ends making it contact the cut-covering assemblies. A cross brace structure is provided on the cut-covering structure so the whole assembly can be moved by the isolator engagement and the isolator can freely slide from one end of the cross brace to the center as the rotating movement progresses.

(20) This engagement moves both sides of the cut-covering assemblies away from the new valve at the same time and rate into the shown position where the seal can reside in the new valve's pipes, cover the gap, and reside in the existing pipe. This procedure allows both seals to be gently placed into position, ready for depressurization of the enclosure that will seal both cut-covering assemblies to the pipe's interior.

(21) FIG. 16 is a side elevation view that presents the completely inserted valve with permanent fittings attached over the cut gap. The typical fitting is known in the industry as a standard coupling. The coupling covers and permanently seals the gap that is temporarily internally plugged by the cut-covering assembly, thereby completing the method of inserting a valve into a live pipeline. These couplings can be installed loose on the new valve's pipe ends during insertion so split style couplings will not have to be used.

(22) FIG. 17 is a side elevation view that shows how multiple clamps can be used to expose more than two work areas of clear smooth pipe cylinder for work that may be required on PCCP pipe.

(23) FIG. 18 is a perspective view of the spring tube and cross braces of an embodiment of a cut-covering assembly.

(24) FIG. 19 is a perspective view of the spring tube and cross braces of another embodiment of a cut-covering assembly.

(25) FIG. 20 is a front elevation view of the spring tube and cross braces of the embodiment of a cut-covering assembly of FIG. 19.

(26) FIG. 21 is a side sectional view of the spring tube and cross braces of the embodiment of a cut-covering assembly of FIG. 19 along line A-A of FIG. 20.

(27) FIG. 22 is a perspective view of an embodiment of a replacement valve assembly.

(28) FIG. 23 is a front elevation view of the replacement valve assembly of FIG. 22.

(29) FIG. 24 is a side sectional view of the of the replacement valve assembly of FIG. 22 along line A-A of FIG. 23.

(30) FIG. 25 is a perspective view of the replacement valve assembly of FIG. 22 attached to a service valve and bonnet.

(31) FIG. 26 is a front elevation view of the replacement valve assembly, service valve and bonnet of FIG. 25.

(32) FIG. 27 is a side sectional view of the replacement valve assembly, service valve and bonnet of FIG. 25 along line A-A of FIG. 26.

(33) The reference numbers in the figures refer to the following:

(34) TABLE-US-00001 Reference Component Number tension wire 1 outside restraining clamp 2 left side restraining clamp 211 right side restraining 212 clamp second left side 2A restraining clamp second right side 2B restraining clamp center restraining clamp 3 bolts (with nuts) 4 concrete coating 5 mounting flange 6 cylinder 7 pressurized enclosure / 9 housing service valve 10 mechanical gland 11 wheels 12 abrasive belts 13 stabilizing member 15 jack screws 17 internal bracket of the 19 housing pipe section 20 new pipe end assemblies 21 new valve body 22 valve body right side 221 valve body left side 222 valve body right side 223 cylinder right side cylinder interior 2231 right side cylinder opening 224 valve body left side 225 cylinder left side cylinder interior 2251 left side cylinder opening 226 central chamber 227 fluid passage 228 operating nut 23 disc (isolator) / valve 24 first medial edge 241 second medial edge 242 seal 26 seal exterior 261 seal interior 262 internal spring tube 25 spring tube exterior 251 spring tube interior 252 cross brace 27 first cross brace 271 second cross brace 272 cross brace medial flange 275 cutting tool 30 bonnet 32 pipe (pipeline) 35 left side of the pipe 351 right side of the pipe 352 left medial portion of the 353 pipe right medial portion of the 354 pipe pipe ends 36 replacement valve 40 assembly gearbox 50 shaft 51 drive unit 52 cut-covering assembly 62 right side cut-covering 621 assembly left side cut-covering 622 assembly rod 72 cut gap 77 receiving cavity 87 wedged rubber 88

DETAILED DESCRIPTION

(35) As seen in FIGS. 1-3, tension wires 1 are embedded within the concrete coating 5 of a pipeline made with PCCP pipe. Restraining clamps 2 remain permanently a part of the pipeline 35 to the keep the wire 1 in tension around cylinder 7 to secure the strength of pipeline 35. Center restraining clamp 3 is temporary and is installed a short distance away from outside clamps 2 to provide smooth areas of cylinder 7 free of wire 1 and concrete 5 without risking the loss of pipe 35 strength. Clamps can be formed from a combination of pieces joined for example by bolts 4, as shown in the illustrated embodiments. Restraining clamps 2 and 3 are designed to hold the various sizes of pipelines 35 and accommodate internal working pressures. A mortar mix can be applied to make up for out-of-round surfaces of concrete 5.

(36) The center restraining clamp 3 can be made up of a combination of pieces to make one clamp or a combination of clamps with multiple pieces as seen in FIG. 1 to make up the center restraining clamp 3. The center clamp 3 is provided with a mounting flange 6 that mates with stabilizing member 15. The stabilizing member 15 preferably attaches to mounting flange 6 by common threading or bolting. Threading is preferred because it is a stabilizing member that allows attachment and detachment (screwing and unscrewing) under pressure. The center restraining clamp 3 is installed around pipeline 35 encircling its concrete coating 5 to secure the tension wires 1 that support cylinder 7.

(37) Clamps 2, 3 are preferably assembled by bolting 4, and the outside clamps 2 are installed a predetermined distance and outside of center-clamp 3. The outside-restraining clamps 2 can consist of a single clamp or a combination of clamps to make up the outside-restraining clamp 2. Bolts and nuts 4 are used to assemble restraining clamps 2,3. These outside restraining clamps 2 can remain as a permanent part of the pipeline 35.

(38) Multiple outside restraining clamps can be used and left in place to provide additional service locations along the steel cylinder 7 for tooling or services. For example, as seen in FIG. 17 a second left side restraining clamp 2A placed to the left of the left side restraining clamp 211 and a second right side restraining clamp 2B placed to the right of the right side restraining clamp 212 can be attached to the pipe 35.

(39) The center restraining clamp 3 seen in FIGS. 1-4 has a smaller width, like that of the new valve 22 with its sub-assemblies 21. The center restraining clamp 3 is removed from its position with pipe section 20 as seen in FIG. 9. When the section 20 is cut by the cutting tool 30 (see FIGS. 5, 7) this removing section 20 includes removal of the center restraining clamp 3 as shown in FIG. 9 while the pipeline 35 is fully pressurized. Enclosure 9 allows equal pressure inside and outside of pipeline 35 so this removal of cut section 20 can be performed. The removal of the center restraining clamp 3 with cut section 20 could not take place without an equal pressure condition of pipeline 35. Once the wire 1 is cut to expose the smooth cylinder 7 and clamp 3 is removed, the wire 1 would separate from cylinder 7 and the unsupported cylinder 7 would run the risk of rupturing after wire 1 is removed.

(40) Using the present method, by encapsulating the center restraining clamp 3 with enclosure 9 to provide exterior pressurization of pipeline 35 with the same pressure as the inside of pipeline 35, no stress exists from internal pressure on cylinder 7. This allows cutting and removing center restraining clamp 3 with the pipe section 20 from pipeline 35 to be safely performed. In addition, equal pressure produced by enclosure 9 allows the cut-covering assemblies 62 to be inserted smoothly with very little resistance and without fluid pressure escaping through gap 77. Unequal pressure would affect the movement of the cut-covering assemblies 62 into the pipe ends 36.

(41) The pressurized enclosure 9 shown in FIG. 4 connects onto the pipeline 35 using mechanical seal or gland 11 that by bolting pushes and compresses a wedged rubber (elastomeric) gasket 88 into a receiving cavity 87 on enclosure 9. The gasket 88 surrounds the pipe and is preferably cut at a tapered angle to form a wedge and wrapped around the pipe in cavity 87 so that when the ring member 11 is tightened it seals the cut rubber edges by compression all the way around the pipe to form a mechanical joint. This multi-piece enclosure 9 is installed on a clear area of a cylinder 7 or on a smooth pipe 35.

(42) Enclosure 9 has a mounting surface 28 where a service valve 10 connects so that a bonnet 32 can be installed and removed to perform various services. Attached to bonnet 32 is a stabilizing member 15 that can be retracted and advanced to restrain clamp 3 by mounting flange 6. Clamp 3 is attached to pipe section 20 to retain the pipe section in position for cutting.

(43) Abrasive belts 13 which rotate on the cutting tool 30 can be used, as shown in FIG. 5 and FIG. 6. At least one gearbox 50 can be provided that can be powered by a shaft 51 that passes through the housing 9 or bonnet 32 to connect to a drive unit 52 so the belts 13 can move to cut the pipeline 35. Using an external drive 52 can allow a hydraulic or electric drive 52 without being under water or pressurized within the housing 9. The provided wheels 12 keep the belt 13 tight and drive the belt to perform cutting of a section of pipe 20 from pipeline 35. Advancing the jack screws 17 on FIG. 7 moves the cutter 30 to advance the cut and retract afterward, i.e., to move the cutter 30 up and down in the housing 9 or bonnet 32. Cut section 20 being attached to clamp 3 allows both to be retracted along with cutting tool 30 by member 15 into the housing 32. Once retracted, the service valve 10 can be closed to isolate pressure found in existing pipeline 35.

(44) As seen in FIG. 9, the housing 32 can be removed from service valve 10. The cutting tool 30 along with the removed pipe section 20 and the center clamp 3 are removed from the housing. As seen in FIG. 10, a new valve 22 with pipe ends 21 can then be attached. Cut-covering assemblies 62 are placed within each pipe end 21 and the valve 22 is secured to stabilizing member 15 and retracted into housing 32 so the housing 32 can be bolted to service valve 10. Once housing 32 is secured to service valve it can be fully opened to pressurize housing 32 allowing the new valve with end assemblies 21 to be installed where pipe section 20 was removed from the existing pipeline 35, creating existing pipe ends 36 as seen in FIG. 10.

(45) As seen in FIG. 11, new valve 22 with attached pipe ends 21 containing cut-covering assemblies 62 are set into alignment by stabilizing member and internal bracket 19 of the enclosure 9. The lower brackets 19 found in the housing 9 are designed to cradle the new valve 22 in true placement and the stabilizing member 15 is set tight to hold valve 22 in place and enable the bores of attached pipe ends 21 and the existing pipe ends 36 to match. The inside diameters of pipes 21 and existing pipe 36 are placed in alignment and in the same plane with one another. This allows the cut-covering assembly 62 to easily slide through all bores of the pipe ends without restriction.

(46) Set within each new valve pipe ends 21 is the cut-covering assembly 62 as seen in FIGS. 12-15. This cut-covering assembly is set within both pipe ends 21 and arranged to clear existing pipe ends 36 while being set into the gap created by removal of cut section 20 as seen in FIG. 12. After the new valve assembly 22 and sub assemblies 21 are in position, the new valve 22 can be operated within the pressurized enclosure 9 by rotating control rod 72 as seen in FIG. 15.

(47) Operating this control rod 72 turns operating nut 23 of the valve 22 to rotate a disc 24 or isolator. As seen in FIG. 15, the isolator disc 24 being opened in pivoting fashion moves the disc 24 out of the valve body 22. This continued pivoting of disc 24 causes direct contact with cross brace 27 of the cut-covering assembly 62, and forces cut-covering assemblies 62 to be pushed away on each side from valve 22 and its secured placement within pipe 21 into pipe ends 36. Cut-covering assembly 62 continues to move into existing pipe ends 36 by direct contact with the isolator 24 until they slide to their predetermined position. At that point the new valve 22 and isolator 24 are in the fully open position. The cut-covering assembly 62 will stay in position due to tension created on seal 26 by the internal spring tube 25 installed as part of the cut-covering assembly 62 and will not obstruct the closing of the valve.

(48) Cut-covering assembly 62 is installed partially into the existing pipeline 36 to a point which is at least enough to cover cut gap 77 (as seen in FIGS. 8, 12, 14, and 15) in fluid-tight engagement. The cut-covering assembly 62 as seen in FIGS. 12, 13, and 14 includes a spring tube inner structure 25 to keep the seal 26 tight against the pipe walls of 21 and 35 inside the pipe diameters. Once cut-covering assembly 62 has traveled into position to cover gap 77, the pressure within the enclosure 9 can be released, causing the seal of cut-covering assembly 62 to seat tightly with the inner walls of pipe 35 and pipe assemblies 21.

(49) Once the temporary enclosure 9 is depressurized, it can be removed from the pipeline 35 and permanent external closure couplings 40 (seen in FIG. 16) are installed to cover gap 77 to complete the valve insertion.

(50) One embodiment of a replacement valve assembly 40 for use in the present method can be seen in FIGS. 22-24. The replacement valve assembly 40 includes a valve body 22 having a right side 221 and a left side 222. The right side 221 of the valve body 22 has a right side cylinder 223 for engaging a right side end of the cut pipe 35, while the left side 222 has a left side cylinder 225 for engaging a left side end of the cut pipe 35. In between the right side cylinder and left side cylinder of the replacement valve assembly 40 is a central chamber 227. The central chamber 227, right side cylinder 223, and left side cylinder 225 are disposed along a longitudinal axis and are in fluid communication so as to form a fluid passage 228 between a right side cylindrical opening 224 of the right side cylinder 223 and a left side cylindrical opening 226 of the left side cylinder 225. The central chamber 227 further includes a rotatable valve 24, which can be a butterfly valve, and can be in the shape of a disc.

(51) Each of the cylinders of the replacement valve assembly 40 includes a cut-covering assembly 62, components of which can be seen in FIGS. 18-21. A right side cut-covering assembly 621 is positioned in an interior 2231 of the right side cylinder 223 and a left side cut-covering assembly 622 is positioned in an interior 2251 of the left side cylinder 225. Each cut-covering assembly includes an elastomeric seal 26, a spring tube 25, and a first cross brace 27. The exterior surface 261 of the elastomeric seal 26 contacts an interior surface of the cylinder of the replacement valve assembly 40, and an exterior surface 251 of the spring tube 25 contacts an interior surface 262 of the elastomeric seal 26. The spring tube exerts pressure (force) outwardly, i.e. on the interior surface 262 of the elastomeric seal 26, and assists in creating a fluid tight seal with the seal 26. One or more cross braces 27 extend within the fluid passage 228 of the valve body 40 in the central portion of the cut-covering assembly 621, extending between a first position 2521 on the interior surface of the spring tube and a second position 2522 on the interior surface of the spring tube 25. The cross braces 27 engage the spring tube 25 and/or the seal 26 so that when a longitudinal force is exerted on the cross brace 27 the cut-covering assembly 62 can be moved outwardly.

(52) In some embodiments, a cut-covering assembly 62 can include both a first cross brace 271 and a second cross brace 272. The cross braces 27 can optionally include a medial flange 275 that extends inwardly toward the central chamber 227 in order to make better contact with the rotatable valve 24. In the illustrated embodiments, the medial flange is a bent rod attached at both ends to the cross brace 27.

(53) When the rotatable valve 24 is rotated between a first position and a second position, a first medial edge 241 of the valve contacts the cross brace(s) of the right side cylinder 223 and urges a right side end of the right side cut-covering assembly 621 out of the right side cylindrical opening 224, i.e. so that the seal 26 and spring tube 25 can be moved into the open end of cut pipe adjacent to the right side of the replacement valve assembly 40. Simultaneously, a second medial edge 242 of the valve 24 (opposite the first medial edge) contacts the cross brace of the left side cylinder 225 and urges a left side end of the left side cut-covering assembly 622 out of the left side cylindrical opening 226 and into the open end of cut pipe adjacent to the right side of the replacement valve assembly 40. In this way, the two open ends of the replacement valve assembly 40 can be placed into fluid communication and fluid-tight engagement with the cut ends of the pipe 35.

(54) An assembly including the replacement valve assembly 40 of FIGS. 22-24, a service valve 10, and a bonnet 32 for use as described above are shown in FIGS. 25-27.

(55) The examples set forth herein are provided to illustrate certain concepts of the disclosure. The apparatus, devices, or components illustrated above may be configured to perform one or more of the methods, features, or steps described herein. Those of ordinary skill in the art will comprehend that these are merely illustrative in nature, and other examples may fall within the scope of the disclosure and the appended claims. Based on the teachings herein those skilled in the art should appreciate that an aspect disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, such an apparatus may be implemented or such a method may be practiced using other structure, functionality, or structure and functionality in addition to or other than one or more of the aspects set forth herein.

Definitions

(56) As used herein, the following terms and variations thereof have the meanings given below, unless a different meaning is clearly intended by the context in which such term is used.

(57) Brace refers to a structural component attached to a structure in order to strengthen and/or support the structure.

(58) Clamp refers to a component which exerts pressure on the outer surface of a pipe in the present system. Clamps used in the present system and method exert sufficient binding force to restrain the tension wires in PCCP pipe with sufficient force to prevent the tension wires from losing tension.

(59) Prestressed Concrete Cylinder Pipe (PCCP) refers to a pipe formed from a concrete core, a thin steel cylinder, high tensile prestressing wires and a mortar coating. The concrete core is the main structural load-bearing component, with the steel cylinder acting as a water barrier between the concrete layers. The prestressing wires produce a uniform compressive pressure in the core that offset tensile stresses in the pipe, and the mortar coating protects the prestressing wires from physical damage and external corrosion.

(60) In addition, the terms above, below, between, and other terms of relative position or orientation as used herein refer to a relative position of one layer with respect to other layers. As such, one layer deposited or disposed above or below another layer may be directly in contact with the other layer or may have one or more intervening layers, unless described otherwise herein.

(61) The term comprise and variations of the term, such as comprising and comprises, are not intended to exclude other additives, components, integers or steps. The terms a, an, and the and similar referents used herein are to be construed to cover both the singular and the plural unless their usage in context indicates otherwise. Ranges which are described as being between two values include the indicated values.