JPH09196277A - Heat-sealed joint of polyethylene pipe - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a heat-sealed connection portion of a polyethylene pipe, which is easy to work, requires no skill, and is small and easy to handle. SOLUTION: A polyethylene short tube having a built-in heating wire is inserted into an axial butted portion of the polyethylene tube, and the heating wire is energized for thermal fusion connection. A recess is provided in the center of the outer surface of the polyethylene short pipe, the abutting portion of the polyethylene pipes is positioned on this recess, and the anticorrosion tape is wound from the outside of the abutting portion. Ensures a thermal fusion connection.
It is advisable to use a non-inductive winding for the heating wire with a built-in polyethylene short tube, start it up from the central recess, and connect it to the outside. In addition, the polyethylene pipe is reinforced, and a structure having a reinforcing layer and an anticorrosion layer on the inner pipe to be the main body is adopted. This structure can also be applied to termination connection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sealed joint for polyethylene pipe. In particular, the present invention relates to an intermediate connecting portion of a polyethylene pipe for high pressure in which a reinforcing layer formed by winding a metal tape or the like is provided on the polyethylene pipe main body, and further a corrosion protection layer is provided. It also relates to a terminal connection in a polyethylene pipe for water cooling.

[0002]

2. Description of the Related Art Polyethylene pipe connection technology For example, in the case of terminal connection, a short pipe with a collar is butt welded to a polyethylene pipe (inner pipe), a metal tape is wound on the welded portion, and a plated wire is wound tightly. Pressed and rolled with anticorrosion tape on it, insert a tapered core (made of metal) into a polyethylene pipe (inner pipe), tighten it from the outside, and reinforce it with a metal tape until it reaches the inner tapered core. A roll. There is no example for the intermediate connection, and the end connection portions of the above method are butted and connected.

Further, in a water cooling polyethylene pipe,
Butt welding method (flange joint) and taper core flange joint are implemented.

[0004]

In both the former and the latter connection examples, since the terminal and the polyethylene pipe are connected only to the inner pipe portion, the connection point is connected to the connection point in order to withstand the hoop stress due to the internal pressure. Workability is poor because it is necessary to wind a reinforcing tape later. At the connection point, the outer diameter is large with a taper in the method of, and the welding bead is raised in the method of, and it is difficult to wind the reinforcing tape in a line and the work is not easy and there is concern that the reinforcing performance may deteriorate. To be done. (If the welding bead is scraped off, the performance of the welded part may be deteriorated.) On the other hand, the latter butt welding method requires skill in connection work and cannot be redone.
Since the welded end face is scraped, it will be shorter if the process is repeated. The connection device becomes large and is not suitable for narrow spaces. A bead rises inside the weld to narrow the passage. With regard to the taper core flange joint of, the connection part is large and heavy. Cost is high. It takes a long time to work to push in the seal fittings. It is not preferable for polyethylene pipes because the polyethylene pipes are expanded by the seal metal fittings and locally a large stress is generated on the surface of the metal fittings on the stairs.

Therefore, the problem to be solved by the present invention is to provide an intermediate connecting portion and a terminating connecting portion of a polyethylene pipe which are easy to work, require no skill, and are small and easy to handle.

[0006]

The connecting portion of the polyethylene pipe provided as an intermediate connection according to the present invention is a short polyethylene pipe having a cylindrical shape and containing a heating wire near the outer surface thereof.
Inserted in the axial butting portion of the polyethylene pipe, by heat-sealing the polyethylene pipe and the polyethylene short pipe by energizing the heating wire, a recess is provided at the center of the outer surface of the polyethylene short pipe, The abutting portion of the polyethylene pipes is positioned on the recess, and the anticorrosion tape is wound from the outside of the abutting portion to ensure the heat fusion connection between the polyethylene pipe and the polyethylene short pipe.

In the above-mentioned connecting portion, it is preferable that a heating wire containing a polyethylene short tube is non-inductively wound to rise from the central recess and to be connected to the outside. Also,
As the polyethylene pipe, it is preferable to adopt a reinforced polyethylene pipe having a reinforcing layer and an anticorrosion layer on an inner pipe which is a main body.

Further, the heat-sealing connection portion of the polyethylene pipe provided as a terminal connection according to the present invention has a polyethylene brim short having a heating wire built in near the outer surface of the cylindrical portion and having a flange portion at one axial end. The pipe is inserted from the end of the polyethylene pipe, and the polyethylene pipe and the short pipe with a flange made of polyethylene are fusion-bonded to each other by energizing the heating wire. A polyethylene pipe and a polyethylene short pipe with a flange are formed by arranging a recess on the end of the polyethylene pipe and positioning the end of the polyethylene pipe on the recess.

In the above-mentioned connecting portion, the main mode is one in which a loose flange is provided on the outer circumference of the cylindrical portion of the polyethylene short pipe with a collar. The polyethylene pipe may have a reinforcing layer and an anticorrosion layer on its body. Polyethylene tubes can be used for water cooling. In this case, the polyethylene pipe may be a single polyethylene pipe.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a specific example of a heat-sealed joint as an intermediate joint of a polyethylene pipe.
In this embodiment, the polyethylene pipes P, P to be connected are butted to each other in the axial direction, and the polyethylene short pipe PJ is inserted so as to straddle the butted portion.
The polyethylene pipes P, P and the polyethylene short pipe PJ are fusion-bonded to each other by heating the electric heating wire contained in the pipe to generate heat.

However, the polyethylene pipe P is formed by reinforcing the inner pipe 1 serving as the main body, and the seat tape 2, the reinforcing tape 3, and the anticorrosion layer 4 are sequentially applied on the inner pipe 1. The end of the polyethylene pipe with the reinforcing layer may only be cut at a substantially right angle, and the anticorrosion tape 5 may be wrapped around the outer periphery of the polyethylene pipe butted portion 6 after fusion. In addition, the thickness of the polyethylene short pipe PJ is set such that at least the portion inside the polyethylene pipe abutting portion has a thickness that can withstand the internal pressure with only the polyethylene short pipe. Therefore, it is not necessary to reinforce the butt portion. However, since the inner pipe 1 does not withstand the axial stress due to the internal pressure, if the portion including the connecting portion is free in the axial direction, the inner pipe will not be affected by the internal pressure, especially near the start portions (both ends) of the heat fusion. It will extend in the axial direction. As a measure against this, the anticorrosion tape 5 is used by being tightly bound and fixed from the outside so as not to be free in the axial direction.

Reinforced polyethylene pipes P, P as described above
As shown in FIG. 2, the polyethylene short tube PJ used for the above has a heating wire 8 built in near the outer surface of the cylindrical tube body 7, and has a circumference at the center of the outer surface. A concave portion 9 continuous in the direction is provided. The heating wire 8 is non-inductively wound and embedded in the tube body 7, its end is raised from the central recessed portion 9, and the polyethylene tube P,
It is drawn out to the outside through the abutting portion of P so that it can be connected to a power source.

With respect to the recess 9, polyethylene pipe P,
By arranging the abutting portion of P and tightly winding the anticorrosion tape 5 from the outside, the heat fusion connection is ensured with the tightening force of the anticorrosion tape 5.

Further, the inner surfaces at both ends in the axial direction are provided with tapers 10 and 10 whose diameter is expanded toward the outside so that resistance is not given to the fluid flowing in the pipe.

FIG. 3 shows a specific example of a heat-sealing connection portion as a terminal connection of a polyethylene pipe. In this embodiment, a short pipe PJ 'made of polyethylene with a collar is inserted into the end of the reinforced polyethylene pipe P similar to that described above, and the heating wire built in the short pipe itself is energized to generate heat. And a short pipe PJ 'made of polyethylene and having a flange, which are heat-sealed together. The loose flange LF is inserted over the polyethylene short pipe PJ '.

Since the reinforced polyethylene pipe P has the same reinforced shape as that of FIG. 1, the same parts as those of FIG. 1 are designated by the same reference numerals as those of FIG. Therefore, regarding the polyethylene pipe P, refer also to the above description with respect to FIG.

Therefore, a polyethylene short pipe with a collar PJ '
Is a cylindrical portion 11 and a collar portion 12 that extends radially from one end of the cylindrical portion in the axial direction to form a main body, and a heating wire 13 is built in near the outer surface of the cylindrical portion 11. is there. Further, a concave portion 14 is provided on the outer circumference of the cylindrical portion.

A polyethylene pipe P is provided for the recess 14.
By wrapping the anticorrosion tape 15 tightly from the outside with the end portion thereof positioned, the heat fusion connection is ensured with the tightening force of the anticorrosion tape 15. Incidentally, the inner surface of the cylindrical portion at the axial end is provided with a taper 16 whose diameter is expanded outward so as not to give resistance to the fluid flowing in the pipe.

The heat fusion splicing portion having the above structure is
Although it functions as a terminal connection for connecting to another fluid device, it can also function as an intermediate connection by flange coupling between loose flanges LF by attaching the structure to both polyethylene pipes to be connected in a straight line.

The polyethylene pipe P provided with the heat-sealing connection portion of this embodiment is suitable for water cooling. In that case,
The polyethylene pipe P itself may be a solid, non-reinforced type.

[0021]

According to the present invention as described above, according to the heat-sealing connection part of polyethylene as the intermediate connection according to the first aspect, the connection work is easy. The designed strength can be obtained at the connection part. (It does not depend on the degree of work).

According to the heat-sealing connection part of polyethylene as the terminal connection according to claim 4, the terminal connection part is smaller and lighter than the conventional one. Small space for connection work. Only the lead wire for energization should be connected to the connection work point. No skill required for work. It is only necessary to apply a predetermined voltage. Do not deform the polyethylene pipe. And the like.

[Brief description of drawings]

FIG. 1 is a front view showing a heat-sealed connection portion of a polyethylene pipe butted portion in a half-section according to an embodiment of the present invention.

FIG. 2 is a front view showing a half section of a short pipe made of PE used in the heat fusion splicing part shown in FIG. 1 according to an embodiment of the present invention.

FIG. 3 is a front view showing, in a semi-sectioned manner, a heat fusion-bonded portion of a polyethylene pipe end portion according to an embodiment of the present invention.

[Explanation of symbols]

 P Polyethylene pipe (reinforcement type) 1 Inner pipe 2 Seat tape 3 Reinforcing tape 4 Anticorrosion layer 5 Anticorrosion tape 6 Butt part PJ Polyethylene short pipe 7 Main body 8 Heating wire 9 Recess PJ 'Polyethylene brim short pipe 11 Cylindrical part 12 Collar 13 Heated wire 14 Recessed portion 15 Anticorrosion tape LF Loose flange

Claims (7)

[Claims] 1. A short polyethylene tube having a cylindrical shape and containing a heating wire near the outer surface thereof is inserted into an axial butting portion of the polyethylene tube, and a polyethylene tube and a polyethylene short tube are formed by energizing the heating wire. By heat fusion connection,
A heat-sealing connection part for a polyethylene pipe, wherein a recess is provided at the center of the outer surface of the polyethylene short pipe, the abutting part of the polyethylene pipe is located on the recess, and an anticorrosion tape is wound from the outside of the abutting part. 2. The heat fusion splicing part for a polyethylene pipe according to claim 1, wherein a heating wire containing a short pipe made of polyethylene is non-inductively wound to rise from a central recess and to be connected to the outside. 3. The heat fusion spliced part of the polyethylene pipe according to claim 1, wherein the polyethylene pipe has a reinforcing layer and an anticorrosion layer on the body thereof. 4. A short pipe with a flange made of polyethylene, which has a heating wire built in near the outer surface of a cylindrical portion and has a flange at one axial end,
It is inserted from the end of the polyethylene pipe, and the polyethylene pipe and the polyethylene short pipe with a flange are heat fusion-bonded by energizing the heating wire, and a recess is formed on the outer periphery of the cylindrical portion of the polyethylene short pipe. Provided is a heat-sealing connection part of a polyethylene pipe, in which an end of the polyethylene pipe is located on the recess and an anticorrosion tape is wound from the outside of the end portion. 5. The heat fusion-bonded joint for polyethylene pipe according to claim 4, wherein a loose flange is provided on the outer periphery of the cylindrical portion of the polyethylene flanged short pipe. 6. The heat-sealed connection part for a polyethylene pipe according to claim 4, wherein the polyethylene pipe has a reinforcing layer and an anticorrosion layer on a main body thereof. 7. The heat fusion spliced part of the polyethylene pipe according to claim 4, wherein the polyethylene pipe is for water cooling.