JPH10332058A - Mechanical type pipe end anticorrosive pipe coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure anticorrosion veness of a pipe inserted into a pipe coupling, to facilitate construction and to adapt it to a retractable engineering method, too by perfectly covering an end surface and an outer peripheral surface of an inner surface lining steel pipe end part to be connected with a flange part and a cylindrical part of an anticorrosive core. SOLUTION: A box nut 12 is screwed in a screw part 16 which a cylindrical coupling main body 11 has on its end part outer periphery and a packing 14 is arranged between an end part of the coupling main body 11 and the box nut 12. An anticorrosive core 22 has a flange part 24 to cover an end surface 23 of an inner surface lining steel pipe 1 to be connected and an outside cylindrical part 25 extending to the outside of the box nut 12 through the inner peripheral side of the packing 14 along an outer peripheral surface of the inner surface lining steel pipe 1 having a resin lining layer 2 on its inner peripheral surface facing against each other in an installed state. Consequently, it is possible to provide a favourable anticorrosive effect and to facilitate construction by adopting an anticorrosive material for a main body material or applying proper surface treatment, etc. on the inner peripheral surface on an inner surface of the coupling main body 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical pipe end anticorrosion pipe joint used for piping of an inner lining steel pipe whose inner surface is coated with a corrosion-resistant resin layer or the like.

[0002]

2. Description of the Related Art For piping such as tap water and water supply around equipment, from the viewpoint of rust prevention and red water countermeasures, the use of an inner lining steel pipe whose inner surface is coated with a resin having high corrosion resistance has become common. When piping is performed using this kind of inner lining steel pipe, it is necessary to prevent corrosion of the steel pipe base exposed at the cut end face of the pipe. For this purpose, a pipe end corrosion-resistant pipe joint is used. Here, in the case of piping work to newly install a piping system, a method of screwing a lining steel pipe with a threaded outer periphery to the pipe joint is adopted, and a threaded pipe end corrosion protection pipe joint is used as the pipe joint. Is done. On the other hand, when repairing or changing pipes such as repairing a damaged part of a part of an existing pipe or changing a part of an existing pipe, a predetermined part of the pipe is cut off and the cut part is removed. In such a case, it is impossible to use a threaded pipe joint because the existing pipe section is generally fixed and the pipe cannot be rotated. In this case, a mechanical pipe end anticorrosion pipe joint is used.

[0003] In the above-mentioned pipe repair or alteration work of an existing pipe, a pull-out method is generally employed. That is, first, a part of the pipe, for example, a damaged pipe is cut off. Next, the respective pipe end portions of the existing pipes left apart on both sides by the cut are inserted into the mechanical type pipe joints. Then, after disposing a short pipe (pipe member) of an appropriate length between the separated pipe ends, the mechanical type pipe end anticorrosion pipe joint is placed at a position bridging the pipe end and the short pipe. , So that the pipe end is inserted into one end of the mechanical type pipe end anticorrosion pipe joint, and the end of the short pipe is inserted into the other end side of the mechanical type pipe end anticorrosion pipe joint. . Next, the mechanical type pipe end anticorrosion pipe joint is tightened to connect the pipe end to a short pipe (pipe member).

Conventionally, as a mechanical type pipe end anti-corrosion pipe joint, a mechanical type pipe end anti-corrosion pipe joint 50 of the type illustrated in FIG. 5 and a core insertion type anti-corrosion pipe joint of the type illustrated in FIG. 6 and FIG. Mechanical pipe end corrosion protection fittings 60 and 70 have been proposed and used.

[0005] Core built-in mechanical pipe end corrosion-resistant pipe joint 5
Reference numeral 0 (see FIG. 5) denotes a joint main body 11 having a threaded portion 16 on both outer peripheral surfaces, a pipe end anticorrosion core 51 provided integrally with the main body inside the joint main body, and a threaded portion of the joint main body. An inner lining steel pipe 1 having a cap nut 12 to be screwed in, a packing 14 for water sealing, and a washer 13 and having a resin lining layer 2 on an inner peripheral surface thereof is formed by an end (base material portion) of the pipe. Grooves 52 provided at both ends of the end protection core 51,
52, the end face of the inner lining steel pipe 1 is protected from corrosion. However, in this type of mechanical-type pipe-end anticorrosion pipe joint 50 with a built-in core, since the pipe-end anticorrosion core 51 is fixed to the inner peripheral side of the joint main body 11, the pipe end portion to be connected is connected. Cannot be provided so as to penetrate through the joint main body, and therefore, the mechanical type pipe end anticorrosion pipe joint with a built-in core alone cannot be used in the above-mentioned pull-out method.

On the other hand, a core-insertion type mechanical pipe end anticorrosion pipe joint 60 (see FIG. 6) has a joint body 11 having threaded portions 16 on both outer peripheral surfaces, and a cap nut screwed into a threaded portion of the joint body. 12, a packing 14 for water sealing, a washer 13, and an anticorrosion core 61 separate from the joint body. Here, the anticorrosion core 61 is connected to the inner surface of the inner lining steel pipe to be connected in a mounted state. Flange 24 extending outward to cover pipe end face
And a seal such as an O-ring 62 or U packing for sealing between the outer periphery of the flange portion and the inner periphery of the joint body.
The anticorrosion core 61 is attached in advance to the pipe end of the inner lining steel pipe to be connected at the time of construction.

In the case of the core-insertion type mechanical pipe end anticorrosion pipe joint 60 having the above-described structure, one end of the pipe to be connected at the time of piping can be penetrated through the joint body 11 of the joint 60. A core-insertion-type mechanical pipe end anticorrosion pipe joint is frequently used as a pipe joint for the pull-out method.

However, when a conventional core-insertion type mechanical pipe end corrosion-resistant pipe joint is used, particularly when it is used in a pull-out method, the joint main body 11 is used in this work.
Is moved with respect to the anticorrosion core 61 attached to the end of the pipe, so that the sealing means such as the O-ring 62 may be damaged by sliding with the inner peripheral surface of the mating pipe joint body 11. Or the position is shifted, and the anticorrosion property may be impaired.

The sealing means includes an O-ring 6
7, a core-insertion type mechanical pipe end anticorrosion pipe joint 70 (in which an annular protruding piece 72 is provided on the outer peripheral surface of the flange portion 24 of the anticorrosion core 71 in contact with the inner peripheral surface of the joint main body, as shown in FIG. FIG. 7) has also been proposed, but when using this kind of anticorrosive pipe joint, in addition to the above-mentioned difficulties, when the axis of the pipe connected to the axis of the joint body is inclined, , There is a difficulty in mounting. 5 to 7, the same components are denoted by the same reference numerals, and a part of the description is omitted in the examples of FIGS. 6 and 7.

In the case of using such a conventional core-insertion type mechanical pipe end anticorrosion pipe joint for piping work by a pull-out method, O-sealing means provided on the anticorrosion core is used.
The ring, the protruding piece, and the like are slid while being pressed against the inner peripheral surface of the joint body during construction. Therefore,
In order to prevent damage to the sealing means or obtain sealing properties, a corrosion-resistant inner peripheral surface member 6 provided on the inner periphery of the pipe joint body is required.
It is necessary to finish the surfaces 3 and 73 on a smooth surface, and it is difficult to increase the number of processing steps and the manufacturing cost.

Further, when a conventional core-insertion type mechanical pipe end anticorrosion pipe joint is used, the anticorrosion core 6 is used.
1, 71 must be attached to the end of the connected inner lining steel pipe, but after piping, it is impossible to visually confirm whether or not the anticorrosion core is actually attached. There is a problem that it is not possible to prevent the problem of tube end corrosion occurring due to the non-attachment of the anticorrosion core.

[0012]

SUMMARY OF THE INVENTION In view of the above, the present invention ensures the corrosion prevention of the end face and the outer peripheral face of a pipe end inserted into a joint body, is easy to manufacture and construct, and is adopted in a pull-out method. It is possible to easily cope with the inclination of the axis of the connection pipe, and it is possible to check the presence or absence of the anticorrosion core after installation from the appearance, mechanical type It is an object to provide a pipe end anticorrosion pipe joint.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a cylindrical joint body having a threaded portion on the outer periphery of an end portion, a cap nut screwed to the threaded portion, and a joint. In a mechanical pipe end anticorrosion pipe joint having a packing disposed on the inner periphery of an end portion of the main body and a corrosion protection core attached to an end of an inner lining steel pipe to be connected, the anticorrosion core is provided for the inner lining steel pipe to be connected. A flange portion covering the end surface, and an outer tubular portion extending to the outside of the cap nut through the inner periphery of the packing along the outer periphery of the end portion of the inner lining steel pipe integrally provided with and connected to the flange portion. And a mechanical pipe end anticorrosion pipe joint having the following.

[0014] The joint body preferably has a tapered surface extending outward on the inner periphery of the end, and the packing is pressed through a washer by screwing the cap nut to the joint body in the mounted state. And presses against the outer cylindrical portion of the anticorrosion core.

Preferably, the anticorrosion core is formed integrally with an inner cylindrical portion which is preferably watertightly inserted into an inner periphery of an inner lining steel tube to be connected, and is formed integrally with an end of the inner cylindrical portion. It comprises a flange portion having an outer diameter substantially equal to the outer diameter, and the outer cylindrical portion provided integrally with the flange portion.

Further, in the present invention, the outer tubular portion of the anticorrosion core can be made of a soft and corrosion-resistant soft material such as rubber.

Further, in the present invention, the outer cylindrical portion of the anticorrosion core is rolled up outward in the axial direction of the pipe joint before being mounted, and the outer cylindrical portion of the outer peripheral side of the flange portion is provided. And the outer tubular portion which is developed at the time of mounting and covers the outer periphery of the end portion of the lining steel pipe.

[0018]

FIG. 1 shows an embodiment of a mechanical pipe end anticorrosion pipe joint according to the present invention. Cylindrical joint body joint 11
Has a threaded portion 16 on the outer periphery of an end thereof, a cap nut 12 is screwed into the threaded portion 16, and a packing 14 is disposed between the end of the joint body and the cap nut. . Reference numeral 22 denotes an anticorrosion core for preventing the end of the connected inner lining steel pipe. The anticorrosion core 22 is, in the mounted state, connected to the inner lining steel pipe 1 which is connected to face (including the case where one is a short pipe).
And a flange portion 24 covering the end surface 23 of the inner surface, and an outside extending outside the cap nut 12 through the inner peripheral side of the packing 14 along the outer peripheral surface of the inner lining steel pipe 1 having the resin lining layer 2 on its inner peripheral surface. It has a tubular portion 25.

The joint body 11 preferably has an outwardly extending tapered surface 19 on the inner periphery of the end, and the packing 14 is screwed into the joint body 11 with the cap nut 12 through the washer 13 in the mounted state. -Is pressed against the outer surface 19 and pressed against the outer cylindrical body 25 of the anticorrosion core.

In the mechanical type pipe end anticorrosion pipe joint of the present invention, the end face and the outer peripheral face inserted into the joint of the inner lining steel pipe 1 to be connected are formed by the flange portion 24 of the anticorrosion core 22 and the outer portion following this. Since it is completely covered with the cylindrical portion 25, a good anticorrosion effect can be obtained. Further, the anticorrosion core 22 is provided at a distance from the inner surface of the joint body 11, and does not seal between the inner surface of the joint body. Therefore, the inner surface of the joint main body 11 needs to be particularly subjected to flat processing or smooth processing only by providing a corrosion-resistant surface by adopting a corrosion-resistant material for the material of the main body or by performing an appropriate surface treatment on the inner peripheral surface. There is no. Further, even in the case of use in the insertion / removal method, the seal means is not damaged as in the case of using the conventional core-insertion type mechanical pipe end anticorrosion pipe joint, and therefore, the anticorrosion performance is impaired. There is no such thing as.

Further, in the mechanical pipe end anticorrosion pipe joint of the present invention, the outer cylindrical portion 25 of the anticorrosion core 22 is attached to the inner circumference of the packing 14 along the outer circumference of the facing end portion of the connection pipe 1 in the mounted state. Since it extends to the outside of the cap nut 12 through the side, it is possible to visually check after installation whether or not the anticorrosion core 22 is attached, and therefore, a problem that occurs due to forgetting to attach the anticorrosion core, etc. Can be prevented beforehand.

The anticorrosion core 22 is formed integrally with an inner cylindrical portion 26 which is inserted into the inner periphery of the inner lining steel pipe 1 to be connected in a water-tight manner and at the end of the inner lining steel pipe 1. It is preferable that the flange portion 24 has substantially the same outer diameter, and the outer tubular portion 25 provided integrally with the flange portion. The anticorrosion core may be manufactured integrally with the inner tubular portion, the flange portion and the outer tubular portion.

The outer cylindrical portion 25 of the anticorrosion core 22 is
It is preferable that the outer tubular portion 25 is made of a soft material such as rubber, which is soft and corrosion-resistant. Of the connecting pipe 1 by the pipe joint can be enhanced.

FIG. 2 shows an example of the anticorrosion core 22 used in the mechanical type pipe end anticorrosion pipe joint of the present invention in a state before it is mounted. The anticorrosion core 22 is approximately equal to the outer diameter of the inner cylindrical portion 26 which is inserted into the inner surface of the inner lining steel tube in a watertight manner, and the inner lining steel tube 1 which is integrally formed and connected to the end of the cylindrical portion 26. A flange portion 24 having an outer diameter; and a cylindrical body 25 'having one end coupled to the flange portion 24 and provided at a position on the outer peripheral side of the flange portion 24 in a state of being rolled up in a roll shape before mounting. It is composed of

FIG. 3 shows a process of attaching the anticorrosion core 22 to the end of the inner lining steel pipe 1 to be connected. The cylindrical part 26 of the anticorrosion core 22 is inserted into the inner peripheral side of the inner lining steel pipe 1, and the flange part 24 is brought into contact with the end face of the inner lining steel pipe 1. Thereby, watertightness between the inner peripheral surface of the inner lining steel pipe 1 and the cylindrical portion 26 is ensured. Next, the cylindrical body 25 ′ rolled up on the outer diameter side of the flange portion 24 is developed to form a cylindrical body 25 along the outer peripheral surface of the inner lining steel pipe 1. When the anticorrosion core having the above configuration is used, the anticorrosion core can be easily attached to the pipe end, which is effective in reducing piping costs.

As shown in FIG. 4, a female screw and a nut 12 'are attached to the inner peripheral surface of the end of the joint main body 11, and the nut 12' is connected to the joint main body 1.
1, and the washer 13 may be pressed against the packing 14.

As described above, when the mechanical pipe end anticorrosion pipe joint of the present invention is used, the end face and the outer peripheral face of the end of the inner lining steel pipe to be connected are formed by the flange portion and the cylindrical portion of the anticorrosion core. The complete coverage ensures that the pipe inserted into the fitting is protected from corrosion. In addition, the anticorrosion core is not pressed against the inner surface of the joint body and is provided separately, so there is no need to apply a smoothing process to the inner periphery of the joint body. Also, it can easily cope with the inclination of the axis of the connecting pipe. Further, since the tubular portion of the anticorrosion core can be confirmed from the outside after the construction, the occurrence of a problem such as forgetting to attach the anticorrosion core is prevented.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view showing an example of a mechanical type pipe end anticorrosion pipe joint of the present invention in a mounted state.

FIG. 2 is a partially cutaway sectional view showing a state before mounting of an example of a corrosion protection core used in the mechanical pipe end corrosion protection pipe joint of the present invention.

FIG. 3 is a partially cutaway sectional view showing a process of attaching the anticorrosion core shown in FIG. 2 to a pipe end of a connecting pipe.

FIG. 4 is a partial sectional view showing another example of the present invention.

FIG. 5 is a cross-sectional view illustrating an example of a conventional core-incorporated mechanical pipe end anticorrosion pipe joint.

FIG. 6 is a cross-sectional view showing an example of a conventional core-insertion type mechanical pipe end anticorrosion pipe joint.

FIG. 7 is a cross-sectional view showing another example of a conventional core-insertion type mechanical pipe end anticorrosion pipe joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner lining steel pipe 2 Lining layer 11 Joint main body 12 Cap nut 14 Packing 16 Screw part 22 Anticorrosion core 24 Flange part 25 Tubular part 26 Tubular part

Claims (5)

[Claims] 1. A cylindrical joint body having a threaded portion on the outer periphery of an end portion, a cap nut screwed to the threaded portion, a packing disposed on an inner peripheral side of the end portion of the joint body, and a connection. In a mechanical type pipe end anticorrosion pipe joint having a corrosion protection core attached to an end of an inner lining steel pipe, the anticorrosion core is provided integrally with the flange part covering the end face of the inner lining steel pipe to be connected. And an outer tubular portion which covers the outer periphery of the end portion of the inner lining steel pipe to be connected and extends to the outside of the cap nut through the inner periphery of the packing along the outer periphery. Mechanical pipe end anticorrosion pipe joint. 2. The joint body has an outwardly tapered surface on the inner periphery of the end portion, and the packing is attached to the taper through a washer by screwing the cap nut to the joint body in a mounted state. The mechanical pipe end anticorrosion pipe joint according to claim 1, wherein the pipe end is pressed against an outer surface and pressed against an outer peripheral surface of an outer cylindrical portion of the anticorrosion core. 3. An inner tubular portion in which the anticorrosion core is water-tightly inserted into an inner periphery of an inner lining steel pipe to be connected, and an outer diameter of the lining steel pipe formed integrally with an end of the inner tubular portion. 3. The mechanical pipe end anticorrosion pipe joint according to claim 1, comprising a flange having an outer diameter substantially equal to the diameter of the outer pipe and the outer tubular portion provided integrally with the flange. 4. The mechanical pipe end anticorrosion pipe joint according to claim 1, wherein the outer cylindrical portion of the anticorrosion core is made of a soft and corrosion-resistant soft material such as rubber. 5. The outer cylindrical portion of the anticorrosion core is located on the outer peripheral side of the flange portion in a state in which the outer cylindrical portion is rolled outward in the axial direction of the pipe joint before being mounted. 5. The mechanical pipe end anticorrosion pipe joint according to claim 4, wherein the pipe end is unfolded at the time of mounting to form an outer cylindrical portion covering an outer periphery of an end portion of the lining steel pipe.