JPH02196627A - Method of inserting rigid plastic pipe for lining into straight pipeline - Google Patents

Abstract

PURPOSE:To insert a rigid plastic pipe wound on a drum into a straight pipeline without generating extension, crack or heat deterioration by heating and softening a plastic pipe by means of the heat inside and outside the pipe during the course from a drum to a straight pipeline inserting hole, and being released from external heating while internal heating is continued in the straight pipeline to cool and harden its outer layer. CONSTITUTION:A plastic pipe 1 passes through rolls 11, 12, 13 successively while being drawn out of a drum 2 and inserted into a straight pipeline (b) by operating a rope 20. The same is heated by vapor from inside and outside of the pipe while passing from the drum 2 into an inserting hole b1 of the straight pipeline (b) and the softened state is uniformalized inside and outside of the pipe to bend and extend the pipe in the specified direction without difficultly. As the pipe is released from external heating simultaneously with starting to travel into the straight pipeline (b), the same is brought into contact with air to be cooled and hardened. As internal heating by vapor is continued in the straight pipeline (b), cooling and hardening are mainly carried out on an outer layer of the plastic pipe 1. The plastic pipe 1 increases its tensile strength and can withstand traction sufficiently by the arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for inserting a hard plastic pipe for lining into a straight pipe line.

The conventional method for lining the inner surface of a pipe is to use a hard plastic pipe as the lining material, and after inserting the hard plastic pipe into the pipe, it is heated and pressurized from the inside to expand in the radial direction of the pipe and adhere to the inner surface of the pipe. A construction method has been proposed. According to the above-mentioned lining construction method, since the inner lining is composed of an expanded hard plastic tube, it has shape retention and high strength, and a high quality inner lining can be obtained.

Among various conduits, for example, power conduit conduits are usually laid in a substantially straight line. In such straight pipelines, lining work is usually carried out over a very long span of about 400 to 500 m in consideration of work efficiency. When inserting a hard plastic pipe as a lining material into a straight pipe line to be repaired, it is necessary to heat and soften the reading pipe in order to make it possible to pull out the plastic pipe from the drum. In long-span construction, a considerable amount of pulling force is required to pull the plastic pipe into the straight pipe, so if the plastic pipe is pulled and inserted into the straight pipe while it is still heated and softened, the plastic pipe will not be pulled into the straight pipe. This causes the inconvenience that it becomes impossible to stretch and insert it. Furthermore, since it takes a considerable amount of time from the start to the end of insertion of the plastic tube, if the heating of the plastic tube continues during this period, there is a concern that the physical properties of the plastic tube will deteriorate due to thermal deterioration.

These problems can be solved to some extent by omitting either the internal or external heating of the plastic pipe. In particular, the heating and softening state of the thick walled portions becomes uneven inside and outside, causing cracks in the plastic tube when being pulled out from the drum, and causing rupture during the heating, softening and expansion operation for inner lining, which is undesirable.

The present invention has been made with the aim of eliminating such problems.

Means for Solving the Problems The present invention provides that when a hard plastic pipe for lining is drawn out from a drum and inserted into a substantially straight pipe line, the plastic pipe is inserted from the drum to the straight pipe insertion opening. In between, the pipe is softened and made flexible by heating from inside and outside the pipe, and inside the straight pipe, it is released from external heating while continuing internal heating, and the outer layer is heated by the air inside the straight pipe. This relates to a method for inserting a hard plastic pipe for lining into a straight pipe line, which is characterized by being cooled and hardened by contact with the pipe.

Function According to the method of the present invention, when a plastic tube is pulled out from a drum, it is heated from both the inside and outside of the tube, so that the radial direction of the tube, especially the thick walled part, becomes uniformly heated and softened inside and outside the tube, making it possible to draw it out smoothly. Become. Therefore, there is no danger of cracks occurring in the plastic tube when it is pulled out from the drum, and the specified quality is maintained.
The plastic pipe can be pulled out from the drum to the insertion opening of the straight pipe line.

Furthermore, since the plastic tube pulled out from the drum is freed from external heating in the straight pipe, the outer layer is cooled and hardened by contact with the air in the straight pipe, increasing its tensile strength.

Therefore, the plastic pipe can sufficiently resist the pulling force applied during insertion, and there is virtually no stretching in the straight pipe, making it possible to insert the plastic pipe into the straight pipe over an ultra-long span of 400 to 500 m. Regardless of the situation, it can be carried out without any problems. Furthermore, since external heating between extremely long spans in the straight pipe line is omitted, the adverse effect on the physical properties of the plastic pipe due to heating is reduced, and the degree of thermal deterioration can be reduced.

EXAMPLES Below, the implementation status of the construction method of the present invention will be explained based on the attached drawings.

Figure 1 is an overall view schematically showing one implementation of the construction method of the present invention, in which a hard plastic pipe (1) is rolled up into a flat tubular shape around a drum (2) and transported to the construction site. Ru.

The hard plastic tube (1) is made of a hard or semi-hard thermoplastic synthetic resin, which softens when heated with a heating fluid such as steam or heated air, and has a softening point of 100° C. or lower, for example. Examples of the synthetic resin include polyvinyl chloride, polyethylene, and polypropylene.

The plastic pipe (1) is 50-100% of the inner diameter of the straight pipe line.
It is formed into a circular cross-section by extrusion molding means so as to have an outer diameter corresponding to the diameter of the tube, and is crushed in the tube radial direction when being wound onto the drum (2) to form a flat tube shape.

Utilizing the time when the plastic tube (1) is wound onto the drum (2), means for supplying a heated fluid such as steam into the plastic tube (1) is provided. Fig. 1 shows an example in which a steam supply hose (3) is applied, and one end of the hose (3) is drawn into the interior through the side plate (2a) of the drum (2), and is connected to the plastic pipe (1). It is connected to the drum inner pipe port by applying an appropriate connection means, and the side plate (2) of the drum (2)
A connecting metal fitting (3a) connected to the steam supply port described below is attached to the other end pulled out outward from a).

At the construction site, a drum support device (4) and a heat insulating casing (5) that houses the device (4) in the center are installed near the shaft (, a) that serves as the work opening. Support device (4
) has a rotatable hollow shaft part (4a) extending in the vertical direction, and the drum (2) is attached to the side plate (2) on this shaft part (4a).
a) The drum (2) is fitted and fixed horizontally in the central shaft hole, and at the same time the drum (2) is hermetically housed in the casing (5).

The upper end of the shaft (4a) of the support device (4) penetrates the upper cover (5a) of the casing (5) and projects upward, and this upper end protrusion (4a+) connects the swivel (6) and the first conduit (
7), it is connected to a boiler (8), and is supplied with steam as appropriate. The shaft portion (4a) has a steam supply port (4a2) at the top, and this supply port (4a)
The hose (3) is connected to a2) at the other end of the connecting fitting (3a).

A lead-out duct (9) is provided in the body of the heat insulating casing (5) so as to approximately match the support height of the drum (2),
This outlet duct (9) and the insertion port (b,) of the straight pipe line (b) to be repaired are connected to a heat insulation duct (10) that is split and removable.
) are connected through.

An upper guide roll (11) is installed in the upper curved part (10a) of the heat insulation duct (10). Also, the lower bent part (10b
) A lower guide roll (12) is installed inside the drum (
2) Plastic tube (1
) from the drum (2) to the upper guide roll (11), and then the upper and lower guide rolls (11) and (12).
The direction is changed by 45 degrees between the two, and the direction is changed by 90'', so that it can be inserted horizontally into the straight pipe (b).

A processing roll (13) configured as shown in FIG. 3 is installed in the lower horizontal part (10c) of the heat insulation duct (10), and converts the plastic pipe (1) from the flat tubular state shown in FIG. It can be processed into the U-shape shown in Figure 3.

This processing roll (13) is a hard plastic tube (1)
This is applied when the outer diameter of the plastic tube (1) is so large that it is difficult to insert it into the pipe in the form of a flat tube as shown in Figure 2.For example, when the outer diameter of the plastic pipe (1) is larger than the inner diameter of the straight pipe (b), 50-70
%, and may be omitted if there is no problem with insertion in a flat tube shape as shown in FIG.

The heat insulation casing (5) and the heat insulation duct (1o) are connected to the second conduit (14) for externally heating the plastic pipe (1).
) and a third conduit (15) to the boiler (8), and is supplied with steam as appropriate from the boiler (8).

In addition, in the figure, (16) is the seal rubber that seals the outlet of the outlet duct (9), and (17) is the heat retention tact (10).
Seal rubber (18) seals the outlet of the drum (
2) is a plastic tube fall prevention roller installed close to the outer periphery; (19) is the same guide roller.

FIG. 1 shows the situation at the beginning of the insertion work.

Before starting work, the plastic pipe (1) is pulled out through the outlet duct (9) and the heat insulation duct (10) to the insertion port (bl) of the straight pipe line (b) by preliminary operations, and ) is connected to the tip of the traction lobe (20) of the wire in the straight pipe (b) via a connecting metal fitting (21). Furthermore, in order to internally heat the plastic tube (1), the steam passes through the boiler (8), the first conduit (7), the swivel (6), the hollow shaft (4a) and the hose (3) in order to heat the plastic tube (1). Steam is supplied from the boiler (8) through the second and third conduits (14) and (15) to externally heat the plastic tube (1). Heat insulation casing (5)
and supplied into the heat insulation duct (10). The plastic pipe (1) is softened by steam heating from the inside and outside of the pipe, so that it can be pulled out from the drum (2) and heated through the heat insulation duct (10).
The vehicle is now ready to pass through the bend, and all preparations are complete for the start of work.

When the rope (20) is operated to pull the plastic pipe (1) in the state shown in Fig. 1, the plastic pipe (1) is pulled out from the drum (2) and rolled onto the roll (11
), (12) and (13) in order, the straight pipe (b
), and finally the entire length is inserted.

During the insertion operation into the straight pipe (b), the plastic pipe (1) is heated from inside and outside the pipe by steam between the drum (2) and the insertion opening (b,) of the straight pipe (b). As a result, the softening state becomes uniform inside and outside the tube, and therefore the drum (2
) When pulling out the insulation duct (10) or passing through a bend in the heat insulation duct (10), the plastic pipe (1) can be freely bent and stretched in the specified direction without strain, without causing cracks or other quality deterioration.
can be pulled out from the drum (2).

Furthermore, the plastic pipe (1) passes through the seal rubber (17) of the heat insulation duct (10) and begins to enter the straight pipe line (b), and at the same time is released from external heating, so that the straight pipe line (b) Inside, it is cooled and hardened by contact with air. Since internal heating by steam continues in the straight pipe (b), cooling hardening mainly occurs in the outer layer of the plastic pipe (1). By cooling and hardening the outer layer, the plastic pipe (
1) increases tensile strength 4, making it possible to sufficiently resist traction force, and hardening reduces frictional resistance with the inner surface of the straight pipe (b). Therefore, the straight pipe line (b) is 400~
Even with an extremely long span of 500 m, the reading pipe (1) can be inserted into the straight pipe (b) without any trouble by towing.

Furthermore, since external heating in the straight pipe line (b) is omitted, external heating of the plastic pipe (1) can be done over an extremely short distance from the drum (2) to the straight pipe insertion port (b+). , the degree of thermal deterioration of the plastic tube (1) can be considerably reduced.

FIG. 4 shows another implementation situation of the present invention, in which the drum (2)
There is no substantial difference from the previous embodiment except that the second embodiment is vertically connected to the ground.

Effects According to the construction method of the present invention, the hard plastic pipe (1) wound around the drum (2) can be inserted into the straight pipe line (b) without substantially elongating, and without cracking or thermal deterioration. It can be inserted without causing any deterioration in quality or physical properties, and is extremely useful especially when carrying out construction work with an ultra-long span of 400 to 500 m. be.

[Brief explanation of the drawing]

Fig. 1 is an overall view schematically showing one implementation of the method of the present invention, Fig. 2 is a cross-sectional view of a hard plastic pipe that has been flattened, and Fig. 3 is an explanation showing the processing situation of a flat plastic pipe with processing rolls. FIG. 4 is an overall view schematically showing another embodiment of the construction method of the present invention. In the figure, (1) is a hard plastic tube, (2) is a drum, (4) is a support device, (5) is a heat insulating casing, and (8) is a support device.
) is a boiler, (9) is a lead-out duct, (10) is a heat insulation duct, and (16) and (17) are seal rubbers.

Claims (1)

[Claims] 1. When a hard plastic pipe for lining is inserted into a substantially straight pipe line while being pulled out from a drum, the plastic pipe is heated from inside and outside the pipe between the drum and the straight pipe insertion opening. inside the straight pipe, it is released from external heating while the internal heating continues, and the outer layer is cooled and hardened by contact with the air inside the straight pipe. A method of inserting a hard plastic pipe for lining into a straight pipe line.