JPS6048676B2 - Method and device for blocking or cutting gas pipes, etc. without excavation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for plugging and cutting underground pipes at or near their connection to the mains without the need for excavation.

More particularly, the present invention relates to the insertion of a heat stabilized and pre-shrunk crosslinked polyolefin plug which is inserted into a tube and expands upon heating. The gas supply industry faces significant time consuming and expense problems with shutting off gas service and removing gas lines from abandoned properties.

Often, regulations require that gas lines be plugged or disconnected at or near the mains when a property has been abandoned for six months or more. This is a safety regulation to prevent explosions and other accidents caused by gas leaks. In order to prevent the pipe from being cut from the main pipe and causing a gas leak when excavated later with heavy equipment, this rule not only requires that the pipe be blocked, but also that the main pipe or its vicinity must be It requires that the pipe be cut. This procedure is preferred even if not required by regulation. The burden on the gas supply industry in terms of the time and expense of blocking and cutting gas pipes is significant.

Prior to this invention, the gas supply industry had to dig at the point where the gas pipe connected to the mains. This point is typically a street or sidewalk. This digging, filling, and resurfacing work is very expensive. The invention makes it possible to plug gas pipes or other similar types of pipes at or near the mains, and then cut them off at the side of the plug farthest from the mains, without having to dig up the ground. This is what I did.

The present invention makes it possible to block underground pipes such as gas pipes at or near the point where they connect to the main pipe by digging up the land and passing the pipe closer to the point where it connects to the main pipe. This is what I did. This method can save you a lot of money. This is particularly important in Yanghe, where it is known that the interruption of the supply of gas or the like to an abandoned property will not result in future income. The cost of digging, plugging pipes, filling holes and resurfacing is a complete loss to the gas and other supply industries. According to the present invention, underground pipes can be closed off at or near the point where they connect to the main pipe by approaching the pipe at the exit point of the land without the need for excavation.

This exit point may be in the basement of an abandoned property. According to the invention, a heat-stabilized, pre-shrunk, cross-linked polymer plug is placed in the heater element and inserted into the gas line from the point where it exits the earth, such as in a basement. The heater element can be mounted on a flexible long shaft having a smaller diameter than the tube into which it is inserted. The plug installed in the heater element is inserted into the pipe and placed at or near the point where the pipe connects to the mains. A heater element is then heated, preferably with an electrical wire passing through the long flexible shaft, to expand the pre-shrinked cross-linked material or polymer to its original cross-linked state and plug the tube. The heater element is then recovered. In a preferred embodiment, a resilient washer is mounted around the long shaft to prevent gas from escaping from the opening of the gas pipe into which the plug is inserted during the process of plugging the pipe.

After the plug is inflated in place, a cutting tool mounted on a long flexible shaft can be inserted into the tube.

Place the cutting tool near the plug and activate it. The cutting tool cuts the tube from the inside of the tube. After the tube is completely cut, the cutting tool and long flexible shaft are retrieved and the operation of plugging and cutting the tube is completed. For the purpose of illustrating the invention, the drawings depict a currently preferred version.

However, the invention is not limited to the arrangements and tools shown. Like numbers indicate like elements in the drawings. FIG. 1 is a front cross-sectional view of a plug and cut tube inserted into a tube according to the present invention, showing the main pipe 12 and the tube 10 installed inside a building wall 14.

Any type of pipe can be used to plug and cut without digging. However, for purposes of illustration and not limitation, the invention will be described with respect to plugging and cutting gas pipes installed from a gas mains. Other types of pipes, such as water pipes, can be plugged or cut in the present invention. Pipe 10 and main 12 are shown buried in ground 16, as is normally done.

A typical sidewalk 18, curbstones 20 and pavement 22 are illustrated. By means of the invention, the pavement 22 and/or
Alternatively, the pipe 10 can be plugged at or near the main pipe 12 without digging up the flagstone 20.

Excavating and moving properties such as pavements, curbstones and sidewalks is very expensive. Just digging up holes and filling them with untended soil is very expensive. The present invention can be used with any suitable tube 10, such as conventional steel, copper or plastic tube.

In accordance with the present invention, a plug 24 is shown in FIG. 1 installed in the pipe 10 at or near the point where it connects to the mains. According to the invention, the pipe 10 is opened in such a way that it is cut or unfitted at a point 26 where it emerges from the ground and is accessible, for example inside the basement of a building where the gas supply is to be shut off. Ru. FIG. 2 is a front view of a plug placed at the end of a heater element 28 inserted into a tube in accordance with the present invention, the plug being expanded by heating placed at the end of the heater element 28; 24 is tube 1
It is set to 0.

3 is a cross-sectional view taken along line 3--3 of FIG. 2 along the centerline of the plug, showing the plug inserted into the tube cut away in FIG. 2, and FIG. 4 shows the heater element and tubular housing. 5 shows a detailed cross-sectional view of the plug installed in the tube with the input element retracted; FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 3;

As can be seen from FIGS. 3, 4 and 5, the plug 24
comprises a resilient plate member 30, which may be constructed of stainless spring steel, beryllium-copper or other suitable resilient material.

The resilient plate member 30 includes an inwardly directed flange 32 along its innermost edge. The flange 32 is slid into the elongated hole 34 of the tubular insertion element 36. Preferably, the tubular insertion element 36 is comprised of a good thermal conductor, such as copper. The flange 32 of the resilient plate member 30 is inserted into the elongated hole 34 of the tubular insertion element 36, and the inner end of the resilient plate member 30 is retained by the flange 32 inserted into the elongated hole 34. In turn, the resilient plate member 30 is wrapped tightly around the tubular insertion element 36.
Preferably, the resilient plate member 30 wraps around the tubular inserting element 36 twice. However, the number of turns of the elastic plate member 30 or tubular insert element 36 is related to the resiliency of the material, the thickness of the material, and the degree of outwardly directed force of the coiled elastic plate member 30 desired. Preferably, the plug 24 is manufactured so that it is installed in a tubular insertion element 36 when supplied to a user.

However, once the plug is installed in the pipe,
Preferably, the tubular insertion element 36 is recovered as it is connected to the heater element by a fastening means such as a fastening screw 38. The rear end 40 of the tubular entry element 36 is connected to the heater element 28
is fitted into an elongated hole 42 in which it is secured with a fixing screw 38 or other suitable fastening means.On the outside of the elastic plate member 30 is a heat-stabilized pre-shrunk cross-linked material 4.
4 is formed.

The heat-stable cross-linked layer 44 can be a polymer, and cross-linked polyolefins such as heat-stabilized pre-shrunk cross-linked polyethylene are preferred, but may also include cross-linked polyvinyl chloride, ABS (acrylonitrile-butadiene-styrene copolymer), polyurethane. DuPont Co., Ltd. (E.I.du)
pOntdeNemOurs&CO. Other crosslinked polymers such as polyolefins doped with metal ions and/or many rubbers such as those sold under the trademark "SURLYN" from ) can be used. Although the term crosslinked polyolefin or polyethylene is used herein as a specific example of a preferred embodiment, crosslinked polymers or other materials may be used in the practice of this invention. Cross-linking of polyolefins can be carried out using ultraviolet light, dicumal peroxide (Dicu
This can be done by chemical means, such as using malper oxide (Malper Oxide), or by radiation. As is known in the art, crosslinked polyolefins or other heat stabilized materials tend to return to their crosslinked size or state when heated. In the present invention, a cross-linked pipe, such as a cross-linked polyethylene pipe, is heated and reduced to its original dimensions. It is enlarged to do so. Stretched crosslinked polymers can be used to form the back end (layer) 44 of the plug 24 of the present invention. When the plug 24 is inserted into the desired tube location, the heater element 28
The crosslinking material layer 44 returns to its normal crosslinked state and expands. This expansion causes the plug to expand in the tube and become firmly fixed in place. Layer 4 of plug 24
4 with a relatively soft adhesive surface layer 48 on the outside of the tube 1?
It joins with the inner surface 50 of.

The surface layer 48 may be comprised of a mastic that has the property of positively adhering to the inner surface 50 of the tube 10. The surface layer 48 need not form a chemical or molecular bond with the tube 10, but rather forms an adhesive mastic on the inner surface 5 of the tube 10.
A strong mechanical connection with 0 is sufficient. Elastic plate member 30
provides a radially outward force on layers 44 and 48 to help expand polymer layer 44 upon heating and also
and 48, thereby prolonging the life of the seal of the plug 24 inserted into the tube. tube 10
When the plug 24 is inserted into the heater element 28, the plug 24 preferably has a tubular insertion element 36 attached thereto, with the rear end 40 of the tubular insertion element 36 inserted into the elongated hole 42 of the heater element 28.
It protrudes from the heater element 28 into which it is inserted and is slid into place.

A locking screw 38 or other suitable securing means secures the tubular insertion element 36 to the heater element 28. Heater element 2
8 is attached to a long flexible tubular shaft 52. The flexible tubular shaft 52 is sufficiently rigid to allow the plug 24 to be forced along the inside of the tube from the entrance for a very long distance, up to 150 feet. There is. But it can reach even further. The tubular element 52 is attached to the support base 5 as shown in the figure.
It can be wrapped around 4. Preferably, an electrical wire 56 passes through the center of tubular shaft 52 and provides power to heating elements 58 and 60 (shown in FIG. 5) of heater element 28. The other end of wire 56 is connected to an electrical control device 62 which controls heating elements 58 and 6? in a known manner. The temperature is controlled by adjusting the current flowing through the Electrical control device 62 is coupled by means of a plug 64 to a suitable electrical outlet, such as electrical outlet 66 illustrated in FIG. Several washers 68 are attached to the shaft 5
Preferably, the heater element 28 is also mounted on the heater element 28.
It is preferable to install it immediately after.

The washer 68 is selected so that it can be easily fitted onto the inner wall of the tube 10, so that the tube 10 is opened at the point 26;
and plug 2 at the front end of heater element 28 on shaft 52
4, substantially prevents loss of fluids such as gas. When the plug 24 with the heater element 28 installed is inserted into a position substantially in or near the main pipe 12, the controller 62 is actuated to heat the plug 24 by means of the heater element 28 at a controlled temperature. do.

When the plug 24 is heated, the polyolefin expands and
Plug 24 is secured in the desired position within tube 10.
The controller 62 is then turned off and the plug 24 is allowed to cool. Heater element 28 and tubular entry element 36 are withdrawn from opening 26 through tube 10. According to a preferred embodiment of the invention, a cutting device 70 located at the end of the flexible tubular shaft 72 is inserted into the tube at a position substantially proximate the plug 24.

Tubular shaft 72 may be the same as flexible tubular shaft 52;
Both shafts can be made of a suitable flexible material with a predetermined stiffness. In a preferred embodiment, fiberglass tubing may be used. A flexible tubular shaft 72 has an electrical wire 74 passing therethrough, and a cutting device 7
0 motor 76 is supplied with power. Power to the motor 76 is supplied by an electrical controller 78, which
8 is connected to an outlet 66. The cutting device 70 includes a telescoping or collapsible blade that is retracted or folded when inserted into the pipe, extended when cutting, and retracted when the cutting device 70 is retrieved from the pipe. In this way, the tube 10 is inserted into the plug 2.
4, completing the process of plugging and cutting the pipe without the need to excavate the ground. After this,
The cutting device 70 and flexible tubular shaft 72 are withdrawn from within the tube 10 and recovered. If the land is excavated in the future and there is a possibility that it will come into contact with or destroy the pipe 10, the pipe 10
By cutting the main pipe 12, damage to the main pipe 12 and the connection to the main pipe 12 can be prevented. As described above, the present invention comprises a method and apparatus for plugging and sealing underground pipes without digging up ground to gain access to the pipes.

Closing and cutting of pipes is done at a considerable distance from the building, close to the point where the pipe joins the main pipe. This distance may be a considerable distance from the point of access to the tube. Preferably, the plug is installed in a tubular insertion element with an elongated hole.
A tubular insert element made of a thermally conductive material is placed and secured to the end of the heater element. The heater element is inserted into the tube by a long flexible shaft through which the electrical wires pass. The long flexible shaft is provided with a sealing means to prevent gas or other fluid from being lost back through the tube when the plug is inserted into the tube and placed in place. Once the plug is in place, preferably in or near the main pipe, the flexible elongate shaft is retrieved together with the heater element and the tubular insertion element attached thereto. The plug remains in place and serves to seal the tube for an extended period of time. The plug is reinforced by a resilient plate spring member.
After the plug has been installed, a cutting element is likewise inserted into the tube and cut just behind the installed plug.
The cutting elements are then retrieved and the operation is completed without the need for expensive and time-consuming earth digging and filling. The invention may be embodied in other forms without departing from its spirit or essential characteristics.

Accordingly, reference should be made to the claims rather than the foregoing specification as indicating the scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a plug inserted into a tube according to the invention and a cut tube; FIG. The front view of the plug, Figure 3, shows the second plug inserted into the cut-out tube of Figure 2.
a cross-sectional view of the plug along the centerline with respect to line 3-3 of the figure;
4 is a detailed cross-sectional view of the plug installed in the tube with the heater element and tubular insertion element removed, and FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 3. 10... pipe, 12... main pipe, 14...
...Building wall, 16...Land, 18...
...Sidewalk, 20...Edge stone, 22...
- Pavement, 24...Plug, 26...Opening location, 28...Heater element, 30...
・Elastic plate member, 32...flange, 34...
...Elongated hole, 36...Tubular inserting element, 3
8... Fixing screw, 40... Rear end of tubular insertion element, 42... Elongated hole, 44...
...Crosslinked material layer, 48...Adhesive layer, 50...
...Pipe inner wall, 54...Support stand, 56...
... Electric wire, 58, 60 ... Heating element, 62.
...Electrical control device, 64 ... Electrical plug, 66 ... Outlet, 70 ... Cutting device, 72 ... Flexible tubular Axis, 74...
...Wire, 76...Motor, 78...
・Electrical control device.

Claims (1)

[Scope of Claims] 1. Approaching the pipe beyond the point where the pipe emerges from the ground; a plug expandable by heating is installed in a heater element, and the heater element has a diameter smaller than that of the pipe. inserting the plug into the pipe; inserting the shaft into the pipe to position the plug in the pipe at or near the main pipe; excavating ground to gain access to the tube, comprising the steps of activating a heater element to cause the plug to be in an expanded state to seal the tube; and recovering the heater element and the shaft. A method of sealing underground pipes or the like at or near the point where the pipe joins the mains without raising the pipe. 2. The plug installation step consists of installing a plug having a heat-stabilized and pre-shrunk layer of cross-linked material around it in the heater element, and activating the heater element to cross-link the layer of cross-linked material. 2. A method according to claim 1, characterized in that said tube is sealed by inflating it to a normal state. 3 a heater element; a thermally conductive tubular element adapted to mount said heater element; an elastic plate member surrounding at least a portion of said tubular element having an external radial force; provided on said elastic plate member; a layer of thermally expandable material; a bonding material layer provided on the layer of thermally expandable material and providing a bonding material between the layer of thermally expandable material and the tube, the layer of thermally expandable material comprising: for accessing said tube, characterized in that it has been previously shrunk to form a tubular plug of smaller diameter, and said layer of thermally expandable material is expanded by heating to its cross-linked state in said tubular plug. A device for sealing an underground gas pipe or similar at or near the point of connection to the mains without excavating the ground. 4 the thermally expandable material layer comprises a thermally stabilized crosslinked material layer;
Claim 3, characterized in that the layer is pre-shrinked after cross-linking to form a tubular plug of smaller diameter and is expanded by heating to the cross-linked state in said tubular plug. The device described. 5 a heater element mounted on one end of the elongated flexible shaft such that the heater element is attached to one end of the tubular element, the shaft inserting the heater element into the tube; 4. The device of claim 3, wherein the device is sufficiently rigid to bend and flexible enough to follow bends in the tube. 6. The invention of claim 6, characterized in that said heater element consists of a cylindrical heater element adapted to be attached to said tubular element and comprises means for securing said tubular element to said heater element. Apparatus according to scope 3. 7. Apparatus according to claim 6, characterized in that the tubular element is removable from the inside of the elastic plate member after the crosslinked layer has expanded in the tube. 8. The device according to claim 5, wherein the shaft is made of glass fiber. 9. The device of claim 5, wherein the shaft is hollow. 10 The shaft comprises one or more elastic washers attached to the outer surface of the shaft behind the heater element, the washers being in intimate contact with the inner wall of the tube, so that the plug is inserted into the shaft. 6. The apparatus of claim 5, wherein the apparatus is adapted to substantially prevent fluid from leaking from the opening of the tube. 11. The apparatus of claim 5, wherein the heater element is electrically actuated and includes an electrical control circuit for regulating the temperature of the heater element. . 12. Apparatus according to claim 9, characterized in that the wire connecting the electric heater element to the electric control device passes through the hollow center of the shaft. 13 that said resilient plate member comprises a radially inwardly directed flange formed longitudinally along an innermost end thereof, said flange being fitted into a longitudinal slot of said tubular element; An apparatus according to claim 3, characterized in that: 14. The device of claim 3, wherein said material is a heat-stabilized crosslinked polyolefin. 15. The apparatus of claim 14, wherein the polyolefin is heat stabilized crosslinked polyethylene.