RU2742961C1 - Method of repairing fiberglass pipes using threaded insert - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to construction and is used in repair of fiberglass pipelines. Method of repair of fiberglass pipeline includes removal of defective area and installation of repair kit elements instead of defective area with fastening and sealing on ends of pipeline adjacent to remote defective area. At that, at least one end of repaired fiberglass pipe is used to grind cone whereon threaded insert is installed with preliminary application of thermosetting adhesive composition on inner surface of threaded insert and/or on outer surface of pipe cone. Then, repair set element with two opposite threads at ends is introduced into raised sections of repaired pipes. Said element when lowering pipeline is rotated, providing its gradual screwing with elements having left internal thread and right internal thread.

EFFECT: technical result is simple and faster method of repairing fiberglass pipeline in complex field conditions, providing reliability and processability of repairing pipelines without using additional equipment.

4 cl, 4 dwg

Description

IPC F16L 55/17

F16L 55/18

METHOD FOR REPAIR OF FIBERGLASS PIPES USING THREADED INSERT

The invention relates to construction and is used in the repair of fiberglass pipelines.

A known method of repairing a fiberglass pipeline (RF patent No. 2193715, publ. 27.11.2002), including the removal of the defective area, the manufacture of the repair area in the form of a metal pipe with sealing elements in the grooves and the calibration of the internal channels of the pipeline from the side of the defective area under the outer diameter of the metal pipe. It is used to repair fiberglass pipelines with high pressure and tightness requirements. In the known method, a pipeline with a defective area is first excavated, the defective area is removed, a repair area is made in the form of a metal pipe with sealing elements in grooves, and the internal channels of the pipeline are calibrated from the side of the defective area to the outer diameter of the metal pipe. Next, a metal pipe is introduced into one section of the pipeline, and then into another, followed by fastening the metal pipe to sections of the pipeline adjacent to the remote section.

The disadvantage of this technical solution is the use of a pipe made of metal, the expansion temperature of which may differ from the expansion temperature of the fiberglass pipeline to be repaired.

There is a known method of repairing a pipeline using a conical composite coupling (patent for a useful model of the Russian Federation No. 174392, publ. 11.10.2017), including removing the insulating coating by an amount exceeding the length of the coupling, filling the defect cavity with a leveling material, applying an adhesive to the cleaned surface of the pipeline and installation of the coupling. Coupling components are glued with side edges during installation on the pipeline. The two parts of the coupling are pulled together by any device, fixed at the ends with tape clamps, after which the belts are dismantled.

The disadvantage of this technical solution is the possibility of repairing only sections of pipelines with a cylindrical outer surface. Fiberglass pipelines have a variable outer diameter at the joints of pipes, as well as in the area of work with pipe tongs. In these areas, it is not possible to install a cone composite coupling. In addition, the proposed technical solution as applied to fiberglass pipelines is more suitable as a temporary repair. This is due to the fact that in the event of defects in fiberglass pipelines, material stratification occurs and, under prolonged exposure to internal pressure, the stratification spreads through the pipe body, which means that the repair of the fiberglass pipeline must be carried out with full or partial replacement of the defective section.

A known method of connecting a pipe made of reinforced thermosetting resin (RF patent No. 2625393, publ. 07/13/2017), including the following steps: fit with an interference fit of the sleeve part of the first pipe into the sleeve part of the second pipe with the formation of a cavity between the sleeve part and the sleeve part; injection of the joint compound into the cavity; and curing of the joint compound. Two pipes are installed side by side so that the inner diameter of the cone of one pipe allows the second pipe to be inserted into it, and so that there is a space or cavity between them. An opening and an injection duct are formed in the outer pipe, so that a joint material or compound can be injected into the opening and duct to fill said space or cavity, thereby creating a reliable mechanical connection between the two pipes.

The disadvantage of this technical solution is the possibility of repairing only fiberglass pipelines with a joint, which provides for free space between the sleeve and the sleeve for filling with the injection mixture. This method does not allow for the repair of pipelines with self-sealing threaded connections made in accordance with API 5B, since the threaded surfaces fit tightly, which eliminates the presence of free space for filling with the mixture.

As the closest analogue, a method of repairing a fiberglass pipeline using a repair kit (RF patent No. 2287733, publ. 20.11.2006) was adopted. In this method, a defective section of the pipeline is removed, a repair kit is installed instead of the removed defective section with fastening and sealing at the ends of the pipeline adjacent to the removed defective section. The repair kit is made in the form of two fiberglass pipes connected by a socket-nipple connection. The repair kit is pre-assembled and shifted in the socket-nipple connection to the total length not exceeding the distance between the free ends of the pipeline being repaired. One of the free ends of the repair kit is joined to the pipeline, the joint is fixed and sealed, the repair kit is positioned relative to the free end of the pipeline until the second end of the repair kit is joined to the pipeline, the joint is fixed and sealed.

When repairing a fiberglass pipeline, it becomes necessary to raise the pipeline before connecting, since the length of the pipe before make-up is greater than the installation length of the pipe by the value of the thread length. If the intersection of the existing pipeline with the one being repaired is located in the area of the repair coupling, the repair is impossible, since the coupling rests against the existing pipeline.

Thus, the disadvantage of this technical solution is the complexity of the repair, the impossibility of repair in the presence of pipeline intersections above the installation site of the repair coupling.

The objective of the invention is to develop a method for repairing a fiberglass pipeline using a fiberglass repair insert.

The technical result is to simplify and accelerate the method of repairing a fiberglass pipeline in difficult field conditions, ensuring the reliability and manufacturability of pipeline repair without the use of additional equipment.

The technical result is achieved in that a method for repairing a fiberglass pipeline includes removing a defective area and installing elements of a repair kit instead of a defective area with fastening and sealing at the ends of the pipeline adjacent to the removed defective area, while at least one end of the repaired fiberglass pipes grind the cone, on which a threaded insert is installed with preliminary application of a thermosetting adhesive composition on the inner surface of the threaded insert and / or on the outer surface of the pipe cone, while an element of the repair kit is introduced into the raised sections of the pipes being repaired, having two opposite threads at the ends, which, when when lowering the pipeline, rotate, ensuring its gradual screwing with elements having a left internal thread and a right internal thread.

The invention is further illustrated by the following drawings.

Fig. 1 - Threaded repair insert.

FIG. 2 - Diagram showing the method of gluing a threaded insert to a damaged pipe.

Fig. 3 is a diagram showing a method for carrying out a thread restoration repair.

Fig. 4 is a diagram showing a method for carrying out repairs with restoration of internal and external threads.

The repair kit consists of the following elements: a fiberglass threaded repair insert with an external standard thread and an internal cone for gluing with the damaged section of the pipeline (Fig. 1, 2); fiberglass couplings with one thread (two right or two left) (Fig. 3.4); fiberglass pipe with opposite threads (Fig. 3.4).

The threaded insert is designed for the repair of fiberglass pipes by restoring all types of threaded connections on damaged pipes.

A repair fiberglass insert, a branch pipe and a sleeve are made by winding glass-roving impregnated with an epoxy binder onto a forming mandrel with subsequent curing at a temperature of 50-220 ° C. When winding, glass roving with a density of 100-2000 Tex is used. The winding angle varies from 0 to 90 °, depending on the type of winding machine.

Repair of a fiberglass pipeline is carried out in the following sequence. The repair section of the pipe is disassembled, the damaged pipe is removed entirely with connections. On the pipe 1 to be repaired, the cone 2 is ground using a special tool (Fig. 2). Next, a thin layer of adhesive is applied to the surface of the cone 2 of the pipe being repaired and the inner surface of the threaded insert 3. The conical design of the threaded insert 3 allows for gluing all layers of the fiberglass pipe along the wall thickness. The threaded insert 3 is tightly installed on the cone 2 and glued flush with the pipe end. In possible variants, if the cone is grooved more than necessary, the end face of the taper of the pipe being repaired can protrude beyond the end face of the repair threaded insert. In this case, after gluing, the protruding part of the cone is cut off with a hacksaw (no more than 10 mm). Then, using a heater, the threaded insert is kept at a predetermined temperature until the adhesive is completely cured.

Then, the elements of the repair kit are installed at the site of the remote section of the pipeline.

Examples of the invention

Example 1

Repair scheme with restoration of external thread (Fig. 3);

Repair with restoration of external threads is performed in the following sequence:

- the damaged pipe is removed;

- a cone is ground at the end of the fiberglass pipe 1 (Fig. 3) with an external thread;

- a threaded insert 3 with a thin layer of epoxy adhesive, cured at a temperature of 20-220 ° C, is glued to the cone.

- at the end of the fiberglass pipe 1 with a threaded insert 3, a fiberglass sleeve 4 with a right-hand internal thread is screwed;

- one end of the branch pipe 5 with an external right-hand thread is screwed into the coupling 4;

- into the other end of the branch pipe 5 with a left external thread, a coupling 6 with a left internal thread is screwed;

- the ends of the pipe rise to a height at which the placement of the pipe 7 between the coupling 6 and the end of the fiberglass pipe 8 is ensured;

- when the branch pipe 7 rotates, the left external thread of the branch pipe 7 is screwed together with the internal thread of the coupling 6 on one side and the right external thread of the branch pipe 7 with the internal thread of the pipe 8 on the other side. When making up, the pipe ends are gradually lowered to their original position.

Example 2

Repair scheme with restoration of internal and external threads (Fig. 4)

Repair with restoration of internal and external threads is carried out in the following sequence:

- the damaged pipe is removed;

- the cone is ground at the end of the fiberglass pipe 1 (Fig. 4) with an external thread;

- a threaded insert 3 with a thin layer of epoxy adhesive, cured at a temperature of 20-220 ° C, is glued to the cone.

- a bell is cut from the end of the fiberglass pipe 8;

- a cone is ground at the end of pipe 8;

- a threaded insert 9 with a thin layer of epoxy adhesive, cured at a temperature of 20-220 ° C, is glued to the cone.

- on pipe 8 with a threaded insert 9, a fiberglass sleeve 10 with a right-hand internal thread is screwed;

- a fiberglass coupling 4 with a right-hand internal thread is screwed onto pipe 1 with a threaded insert 3;

- one end of the branch pipe 5 is screwed into the coupling 4;

- into the other end of the branch pipe 5, a coupling 6 with a left internal thread is screwed;

- the ends of the pipes rise to a height at which the placement of the pipe 7 between the coupling 6 and the pipe 8 is ensured;

- when the branch pipe 7 rotates, the left thread of the branch pipe 7 is screwed together with the coupling 6 on one side and the right thread of the branch pipe 7 with the right internal thread of the coupling 10. When screwing, the pipe ends are gradually lowered to their original position.

The advantage of the invention is to simplify and accelerate the method of repairing a fiberglass pipeline in difficult field conditions, ensuring the reliability and manufacturability of repairing pipelines without the use of additional equipment, the conical design of the threaded insert allows gluing all layers of the fiberglass pipe along the wall thickness.

Claims (4)

1. A method for repairing a fiberglass pipeline, including removing a defective area and installing elements of a repair kit instead of a defective area with fastening and sealing at the ends of the pipeline adjacent to a remote defective area, characterized in that at least one end of the repaired fiberglass pipe is ground a cone , on which a threaded insert is installed with preliminary application of a thermosetting adhesive composition on the inner surface of the threaded insert and / or on the outer surface of the pipe cone, while an element of the repair kit is introduced into the raised sections of the pipes being repaired, having two opposite threads at the ends, which is rotated when the pipeline is lowered , ensuring its gradual screwing with elements having a left internal thread and a right internal thread. 2. A method for repairing a fiberglass pipeline according to claim 1, characterized in that a repair kit is used, which includes a threaded repair insert, a coupling and a branch pipe. 3. A method of repairing a fiberglass pipeline according to claim 1, characterized in that before installing the elements of the repair kit, a bell is removed from one end of the fiberglass pipe, followed by the formation of a cone. 4. A method for repairing a fiberglass pipeline according to claim 1, characterized in that an epoxy adhesive is used as an adhesive applied to the surface of a threaded repair insert and a pipe.

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