JP7016140B2 - Pipe fittings - Google Patents

Description

The present invention relates to a pipe joint coated with a galvanized film.

Generally, metal (for example, carbon steel) pipe fittings are known. The pipe joint is made to have corrosion resistance by covering the entire surface of the pipe with a zinc-plated film. Since the pipe joint connects a plurality of metal pipes to each other, the pipe joint is connected to each metal pipe by welding.

When a pipe joint is connected to a metal pipe by welding, the zinc plating film melts due to welding heat to generate toxic gas (zinc gas), and welding defects due to the penetration of the zinc plating film are induced.
In order to suppress the generation of toxic gas (zinc gas) and eliminate welding defects, at the piping site (construction site), before welding, use a grinding tool such as a grinder to weld the pipe joint (pipe end). ) Has been removed from the zinc plating film, resulting in deterioration of workability.

The present invention is to provide a pipe joint capable of suppressing the generation of toxic gas (zinc gas) and welding defects and improving workability when connected to a metal pipe.

The first aspect of the present invention is a carbon steel pipe in which a metal joint pipe body is connected to a metal pipe by welding, and an outer peripheral chamfering portion is not formed on the outer peripheral surface of the pipe end portion following the pipe end surface. The metal pipe is provided with a joint pipe body in which the entire surface of the pipe end surface of the carbon steel pipe and the outer peripheral surface of the pipe following the pipe end surface is coated with a zinc-plated coating, and the metal pipe is a non-plated pipe end surface and a non-plated pipe end surface. It has a non-plated outer peripheral chamfering portion and a non-plated outer peripheral chamfering surface following the non-plated outer peripheral chamfering surface, and the entire surface of the pipe outer peripheral surface excluding the non-plating outer peripheral chamfering portion and the non-plating outer peripheral chamfering portion. The joint pipe body is formed by coating the carbon steel pipe with a zinc plating film, and the entire surface of the pipe end surface of the carbon steel pipe and the outer peripheral surface of the pipe following the pipe end surface is coated with the zinc plating film. A non-plated pipe end face formed by removing the zinc-plated coating by cutting and abutting against the non-plated pipe end face of the metal pipe, and a pipe end portion of the joint pipe body following the non-plated pipe end face of the joint pipe body. While removing the zinc-plated coating from the outer peripheral surface of the pipe by cutting, the zinc-plated coating is formed on the outer peripheral surface of the pipe end of the joint pipe body following the non-plated pipe end surface of the joint pipe body by cutting . The non-plated outer peripheral chamfering portion that forms a groove between the non-plated outer peripheral chamfering portion of the metal pipe in which the non-plated pipe end surface is butted against the non-plated pipe end surface, and the non-plated outer peripheral portion of the joint pipe body. It has a non-plated pipe end outer peripheral surface portion formed by removing the zinc plating film from the pipe outer peripheral surface of the pipe end portion following the chamfered portion , and is connected to the metal pipe by welding along the groove portion. It is a pipe joint characterized by the fact that.
In claim 1, the galvanized film is removed from the pipe end surface and the galvanized film is removed from the pipe outer peripheral surface of the pipe end portion following the pipe end surface by cutting (cutting by a machine tool), and at the same time by cutting. An outer peripheral chamfer is formed on the outer peripheral surface of the pipe end that follows the pipe end surface, and the galvanized film is removed from the outer peripheral surface of the pipe at the pipe end that follows the outer peripheral chamfer by grinding (grinding with a grinding machine tool). A configuration that forms the outer peripheral surface of the pipe end can also be adopted.
In claim 1, the galvanized film is removed from the pipe end surface and the zinc plating film is removed from the pipe outer peripheral surface of the pipe end portion following the pipe end surface, and an outer peripheral chamfering portion is formed on the pipe outer peripheral surface of the pipe end portion following the pipe end surface. Can also be adopted.
The first aspect is a pipe joint provided with a metal joint pipe body, the pipe end surface of the joint pipe body is abutted against the pipe end surface of the metal pipe, and the joint pipe body is connected to the metal pipe by welding. The pipe body is a non-plated pipe formed on the outer peripheral surface of the pipe end of the pipe end following the pipe end surface and the outer peripheral surface of the pipe end of the pipe end following the outer peripheral chamfering portion. A configuration having an outer peripheral surface portion of the end, an outer peripheral surface of the pipe excluding the outer peripheral chamfering portion and the outer peripheral portion of the pipe end, and an inner outer peripheral surface portion formed by covering the entire inner peripheral surface of the pipe with a zinc plating film can also be adopted.

According to claim 1 of the present invention, the pipe end surface of the joint pipe body and the pipe end portion (outer peripheral chamfering portion and pipe end outer peripheral surface portion) following the pipe end surface are non-welded regions that are not covered with the zinc plating film. Even if the pipe end surface of the joint pipe body is abutted against the pipe end surface of the metal pipe and the joint pipe body is connected to the metal pipe by welding, the generation of toxic gas (zinc gas) and welding defects due to the melting of the zinc plating film can be suppressed. ..
According to the first aspect of the present invention, before the pipe joint is brought to the construction site (piping site), the pipe end surface is cut with a zinc plating film from the pipe end surface by cutting using a machine tool, and the pipe at the pipe end portion continuing to the pipe end surface. While removing the zinc plating film from the outer peripheral surface, an outer peripheral chamfering portion can be formed on the outer peripheral surface of the pipe end portion that continues to the pipe end surface, and further, the outer peripheral surface of the pipe end portion that continues to the outer peripheral chamfering portion by grinding using a grinding machine. Since the zinc plating film can be removed from the surface to form the outer peripheral surface of the pipe end, it is not necessary to remove the zinc plating film at the construction site (piping site), and workability can be improved.

It is a perspective view which shows the pipe joint (elbow pipe joint). It is a front view which shows the pipe joint (elbow pipe joint). It is a rear view which shows the pipe joint (elbow pipe joint). It is a top view which shows the pipe joint (elbow pipe joint). (A) is a side view showing a pipe joint (elbow pipe joint), (b) is an enlarged view of a main part showing one pipe end portion of FIG. 5 (a), and (c) is FIG. 5 (a). It is an enlarged view of the main part which shows the other pipe end part of. It is a bottom view which shows the pipe joint (elbow pipe joint). FIG. 4 is a cross-sectional view taken along the line AA of FIG. (A) is a pipe joint (elbow pipe joint), and (b) is a side view showing a joint pipe main body in which the entire surface of each pipe end surface, pipe outer peripheral surface and pipe inner peripheral surface is covered with a zinc plating film. It is sectional drawing of FIG. 8A. (A) is a pipe joint (elbow pipe joint), and (b) is a side view showing a joint pipe main body in which an outer peripheral chamfered portion (non-plated chamfered portion) is formed, and (b) is a cross-sectional view of FIG. 9 (a). be. (A) is a pipe joint (elbow pipe joint), and is a side view showing a joint pipe main body in which a pipe end outer peripheral surface portion (non-plated pipe end outer peripheral surface portion) is formed, and (b) is a grinding machine and a joint pipe. It is a side view which shows the main body. It is a side view which shows the state which connected the joint pipe main body of a pipe joint (elbow pipe joint) to a metal pipe by welding. (A) is a side view showing a pipe joint (elbow pipe joint), and (b) is a sectional view of FIG. 12 (a). (A) is a side view showing a pipe joint (reducer pipe joint), and (b) is a sectional view of FIG. 13 (a). (A) is a side view showing a pipe joint (tee pipe joint), and (b) is a cross-sectional view of FIG. 14 (a). (A) is a side view showing a pipe joint (cap), and (b) is a cross-sectional view of FIG. 15 (a).

The pipe joint according to the present invention will be described with reference to FIGS. 1 to 15.

In FIGS. 1 to 7, the pipe joint X is formed of a metal (for example, carbon steel) in a cylindrical shape. The pipe fitting X is, for example, an elbow pipe fitting (hereinafter referred to as “elbow pipe fitting X”).
As shown in FIGS. 1 to 7, the pipe joint X includes a metal (for example, carbon steel) joint pipe main body 1.

As shown in FIGS. 1 to 7, the joint pipe main body 1 is formed in a cylindrical shape. The joint pipe body 1 is formed by bending a carbon steel pipe into an arc shape having an angle of 90 degrees (mandrel molding), for example.
The joint pipe main body 1 has both non-plated pipe end faces 1A and 1B (non-plated pipe end faces 1A and 1B).
In addition, "non-plating" means that the metal surface is not covered with the zinc plating film M, that is, the metal surface is exposed (hereinafter, the same applies).

As shown in FIGS. 1 to 7, the joint pipe main body 1 has a non-plated outer peripheral chamfered portion 3 and 3 (non-plated outer peripheral chamfered portion 3 and 3) and a non-plated pipe end outer peripheral surface portion 4 and 4 (non-plated pipe). It has an edge outer peripheral surface portion 4, 4) and a plating inner outer peripheral surface portion 5.

The non-plated outer peripheral chamfered portions 3 and 3 (bevel ends) are formed on the pipe outer peripheral surfaces 1E of the pipe end portions 1a and 1b following the pipe end surfaces 1A and 1B, respectively. The non-plated outer peripheral chamfered portions 3 and 3 are formed so as to be inclined from the pipe end surfaces 1A and 1B toward the pipe outer peripheral surface 1E (the pipe outer peripheral surface 1C of the joint pipe main body 1). The non-plated outer peripheral chamfered portions 3 and 3 are inclined with an angle θ = 32.5 degrees with respect to the tube end surfaces 1A and 1B, for example. The non-plated outer peripheral chamfered portions 3 and 3 are formed over the circumferential direction P of the joint pipe main body 1.

As shown in FIGS. 1 to 7, the non-plated pipe end outer peripheral surface portions 4 and 4 are formed on the pipe outer peripheral surface 1E of the pipe end portions 1a and 1b following the non-plated outer peripheral chamfered portions 3 and 3. The non-plated pipe end outer peripheral surface portions 4 and 4 are formed along the pipe center line a of the joint pipe main body 1. The non-plated tube end outer peripheral surface portions 4 and 4 are formed from the non-plated outer peripheral chamfered portions 3 and 3 with a non-plating width h. The non-plated tube end outer peripheral surface portions 4 and 4 are formed, for example, having a non-plating width h = 5 to 20 mm.
The non-plated pipe end outer peripheral surface portions 4 and 4 are formed over the circumferential direction P of the joint pipe main body 1.

As shown in FIGS. 1 to 7, the plated inner peripheral surface portion 5 covers the entire surface of the pipe outer peripheral surface 1C and the pipe inner peripheral surface 1D excluding the non-plated outer peripheral chamfered portions 3 and 3 and the non-plated pipe end outer peripheral surface portions 4 and 4. It is formed by coating with a zinc plating film M.

Next, the production of the pipe joint X will be described with reference to FIGS. 8 to 10.
In FIGS. 8 to 10, the same reference numerals as those in FIGS. 1 to 7 have the same members and the same configuration, and therefore detailed description thereof will be omitted.

In FIG. 8, the pipe joint X includes a metal joint pipe body 1 in which the entire surface of the pipe end surfaces 1A and 1B, the pipe outer peripheral surface 1C, and the pipe inner peripheral surface 1D is coated with a zinc plating film M.
As shown in FIG. 8, the galvanized film M is obtained by subjecting the joint pipe body 1 to hot-dip galvanizing (hot-dip galvanizing treatment) on the entire surfaces of the pipe end surfaces 1A and 1B, the pipe outer peripheral surface 1C, and the pipe inner peripheral surface 1D. It is formed in and covers the entire surface of the joint pipe body 1.

In FIG. 9, the joint pipe main body 1 in which the entire surface of the pipe is covered with the galvanized film M is the outer periphery of the pipe end portions 1a and 1b following the galvanized film M and the pipe end surfaces 1A and 1B from the pipe end surfaces 1A and 1B. Outer peripheral chamfering portions 3, 3 (non-plated outer peripheral chamfering portions 3, 3) formed on the outer peripheral surface 1E of each tube end 1a, 1b following the tube end faces 1A, 1B while removing the galvanized film M from the surface 1E. ).
For the outer peripheral chamfering portions 3, 3, for example, the zinc plating film M is formed from the pipe end surfaces 1A and 1B by cutting, and the zinc plating film M is formed from the pipe outer peripheral surfaces 1E of the pipe end portions 1a and 1b following the pipe end surfaces 1A and 1B. While removing (while removing), the zinc plating film M is formed on the outer peripheral surface 1E of each tube end 1a and 1b at the same time as the removal.
The outer peripheral chamfered portions 3 and 3 can be cut using a machine tool [lathe, NC (numerical control) lathe, milling machine, machining center, etc.].

In FIG. 10, the joint pipe main body 1 on which the outer peripheral chamfering portions 3 and 3 are formed is formed by removing the galvanized film M from the pipe outer peripheral surfaces 1E of the pipe end portions 1a and 1b following the outer peripheral chamfering portions 3 and 3. It has tube end outer peripheral surface portions 4, 4 (non-plated tube end outer peripheral surface portions 4, 4).
The pipe end outer peripheral surface portions 4 and 4 are formed by removing the zinc plating film M from the pipe outer peripheral surface 1E of the pipe end portions 1a and 1b following the outer peripheral chamfered portions 3 and 3 by grinding, for example.

The pipe end outer peripheral surface portions 4, 4 (non-plated pipe end outer peripheral surface portions 4, 4) are formed by using a grinding machine Y (grinding device) as shown in FIG. 10 (b).
As shown in FIG. 10B, the grinding machine Y urges the table 102 having the work support protrusion 101, the electric motor 103 for rotating the table 102, the grindstone 104, and the grindstone 104 toward the table 102. It is equipped with a mechanism 105 (a urging device). The grindstone 104 is formed on a circular plate, and the plate thickness h1 is the same as the non-plating width (h1 = h). The urging mechanism 105 urges the grindstone 104 toward the table 102 by, for example, a spring or air (compressed air).

In FIG. 10B, the joint pipe main body 1 having the outer peripheral chamfered portions 3 and 3 formed is placed on the table 102 from one pipe end surface 1B. At this time, the joint pipe main body 1 is fitted onto the work support protrusion 101 from one of the pipe end surfaces 1B, and the pipe end surface 1B abuts on the table 102. The work support protrusion 101 is inserted into the joint pipe body 1 from one of the pipe end surfaces 1B, and an annular ring rubber (not shown) abuts on the pipe inner peripheral surface 21D in a press-fitted state. As a result, the work support protrusion 101 rotatably fixes the joint pipe main body 1 to the table 102.
When the joint pipe main body 1 is fixed to the table 102, the electric motor 103 is driven to rotate the table 102 (work support protrusion 101) and the joint pipe main body 1.
When the joint pipe main body 1 is rotated, the grindstone 104 is arranged at a position continuous with one of the outer peripheral chamfered portions 3 of the joint pipe main body 1. Subsequently, the grindstone 104 is pressed against the pipe outer peripheral surface 1E of the pipe end portion 1b of the joint pipe main body 1 by the urging force (spring force or the like) of the urging mechanism 105, and the pipe outer peripheral surface 1E of the pipe end portion 1b is galvanized. Remove the film M.
As a result, in the joint pipe main body 1, the pipe end outer peripheral surface portion 4 (non-plated pipe end outer peripheral surface portion 4) is formed on the pipe outer peripheral surface 1E of the pipe end portion 1b following the one outer peripheral chamfered portion 3. A pipe end outer peripheral surface portion 4 having a non-plating width h is formed on the pipe end portion 1b of the joint pipe main body 1 [see FIG. 10 (a)].

In FIG. 10B, when the pipe end outer peripheral surface portion 4 is formed on the pipe end portion 1b, the grindstone 104 is retracted from the table 102 and the driving of the electric motor 103 is stopped.
Subsequently, the joint pipe main body 1 is pulled out from the work support protrusion 101, and the joint pipe main body 1 is externally fitted (press-fitted) into the work support protrusion 101 from the other pipe end surface 1A, whereby the joint pipe main body 1 is fitted into the table 102. It is fixed so that it cannot rotate.
Similar to one pipe end portion 1b, the zinc plating film M is removed from the pipe outer peripheral surface 1E of the pipe end portion 1a following the other outer peripheral chamfered portion 3 by using a grinding machine Y (grinding stone 104).
As a result, in the joint pipe main body 1, the pipe end outer peripheral surface portion 4 (non-plated pipe end outer peripheral surface portion 4) is formed on the pipe outer peripheral surface 1E of the pipe end portion 1a following the other outer peripheral chamfered portion 3. A pipe end outer peripheral surface portion 4 having a non-plating width h is formed on the pipe end portion 1a of the joint pipe main body 1 [see FIG. 10 (a)].
Further, the outer peripheral surface 1C of the pipe excluding the outer peripheral chamfered portions 3 and 3 and the outer peripheral surface portions 4 and 4 of the pipe end, and the entire surface of the inner peripheral surface 1D of the pipe become the inner peripheral surface portion 5 of the plating coated with the zinc plating film M.

As shown in FIG. 11, the pipe joint X (elbow pipe joint) connects (connects) the joint pipe body 1 to the metal pipe Z by welding.
As shown in FIG. 11, the metal pipe Z is, for example, a cylindrical carbon steel pipe. Like the pipe joint X (joint pipe main body 1), the metal pipe Z has a non-plated pipe end surface 81A, a non-plated outer peripheral chamfering portion 83, a non-plated pipe end outer peripheral surface portion 84, and a plated inner outer peripheral surface portion 85. .. In the metal tube Z, the inner peripheral surface portion 85 of the plating is formed by covering the outer peripheral surface of the tube excluding the outer peripheral chamfered portion 83 and the outer peripheral surface portion 84 of the tube end, and the entire inner peripheral surface of the tube with the zinc plating film M.

In FIG. 11, in the pipe joint X (elbow pipe joint), one pipe end surface 1A (non-plated pipe end surface 1A) of the joint pipe body 1 is butted against the pipe end surface 81A (non-plated pipe end surface 81A) of the metal pipe Z.
As a result, the groove portion K is formed between the outer peripheral chamfered portion 3 (non-plated outer peripheral chamfered portion 3) of the joint pipe main body 1 and the outer peripheral chamfered portion 83 (non-plated outer peripheral chamfered portion 83) of the metal pipe Z.
Subsequently, the joint pipe main body 1 is connected (connected) to the metal pipe Z by welding along the groove portion K.
At this time, even if the joint pipe main body 1 is connected to the metal pipe Z by welding, the pipe end surface 1A, the outer peripheral chamfering portion 3, and the pipe end outer peripheral surface portion 4 of the pipe joint X (elbow pipe joint) are covered with a galvanized film M. Since it is an uncovered region, it is possible to suppress the generation of toxic gas (zinc gas / zinc fume) and welding defects due to the melting of the galvanized film M.

In the pipe joint X, the elbow pipe joint has been described, but the present invention is not limited to this, and various pipe joints may be used as shown in FIGS. 12 to 15. In FIGS. 12 to 15, the same reference numerals as those in FIGS. 1 to 11 have the same members and the same configuration, and therefore detailed description thereof will be omitted.

In FIG. 12, the pipe fitting X is an elbow pipe fitting. The pipe joint X includes a metal (for example, carbon steel) joint pipe main body 21.
The joint pipe main body 21 is formed in a cylindrical shape. The joint pipe main body 21 is formed into an arc shape having an angle of 90 degrees, for example, and the diameter is gradually increased from one pipe end surface 21A toward the other pipe end surface 21B.
The joint pipe main body 21 has the non-plated pipe end surfaces 21A and 21B, the non-plated outer peripheral chamfering portions 3 and 3, and the non-plated pipe end outer periphery, as described with reference to FIGS. 1 to 7 (joint pipe main body 1). It has surface portions 4, 4 and an inner peripheral surface portion 5 inside the plating. As shown in FIG. 12, the plating inner peripheral surface portion 5 covers the entire surface of the pipe outer peripheral surface 21C and the pipe inner peripheral surface 21D excluding the non-plated outer peripheral chamfered portions 3 and 3 and the non-plated pipe end outer peripheral surface portions 4 and 4 with a zinc plating film. It is formed by covering with M.

The pipe joint X of FIG. 12 includes a joint pipe main body 21 in which the entire surface of the pipe end surfaces 21A and 21B, the pipe outer peripheral surface 21C, and the pipe inner peripheral surface 21D is coated with a zinc plating film M, as described with reference to FIG. ..
The joint pipe body 21 in which the entire surface of the pipe is covered with the galvanized film M is the pipe end portions 21a and 21b following the galvanized film M and the pipe end surfaces 21A and 21B from the pipe end surfaces 21A and 21B as described with reference to FIG. While removing the galvanized film M from the outer peripheral surface 21E of the pipe, the outer peripheral chamfering portions 3 and 3 formed on the outer peripheral surface 21E of the pipe end portions 21a and 21b following the respective pipe end surfaces 21A and 21B are provided. The outer peripheral chamfered portions 3 and 3 are formed by, for example, cutting (machine tool) in the same manner as described with reference to FIG.
The joint pipe main body 21 is formed by removing the zinc plating film M from the pipe outer peripheral surfaces 21E of the pipe end portions 21a and 21b following the outer peripheral chamfered portions 3 and 3, as described with reference to FIG. It has 4 and 4. The pipe end outer peripheral surface portions 4 and 4 have a non-plating width h along the pipe center line a of the joint pipe main body 21, and are formed by, for example, grinding (grinding machine Y) in the same manner as described with reference to FIG. ..
In the pipe joint X of FIG. 12, the pipe end surface 21A of the joint pipe body 21 is abutted against the pipe end surface 51A of the metal pipe Z, and the joint pipe body 21 is connected to the metal pipe Z by welding, as described with reference to FIG. connect.

In FIG. 13, the pipe fitting X is a reducer pipe fitting. The pipe joint X includes a metal (for example, carbon steel) joint pipe main body 31.
The joint pipe main body 31 is formed in a cylindrical shape. As shown in FIG. 13, the diameter of the joint pipe main body 31 is gradually reduced from one pipe end surface 31A toward the other pipe end surface 31B.
The joint pipe main body 31 has the same as described with reference to FIGS. 1 to 7 (joint pipe main body 1), each of the non-plated pipe end faces 31A and 31B, the non-plated outer peripheral chamfering portions 3 and 3, and the non-plated pipe end outer periphery. It has surface portions 4, 4 and an inner peripheral surface portion 5 inside the plating. As shown in FIG. 13, the plating inner peripheral surface portion 5 covers the entire surface of the pipe outer peripheral surface 31C and the pipe inner peripheral surface 31D excluding the non-plated outer peripheral chamfered portions 3 and 3 and the non-plated tube end outer peripheral surface portions 4 and 4 with a zinc plating film. It is formed by covering with M.

The pipe joint X of FIG. 13 includes a joint pipe main body 31 in which the entire surface of the pipe end surfaces 31A and 31B, the pipe outer peripheral surface 31C, and the pipe inner peripheral surface 31D is coated with a zinc plating film M, as described with reference to FIG. ..
The joint pipe main body 31 in which the entire surface of the pipe is covered with the galvanized film M is the pipe end portions 31a and 31b following the galvanized film M and the pipe end surfaces 31A and 31B from the pipe end surfaces 31A and 31B as described with reference to FIG. While removing the galvanized film M from the outer peripheral surface 31E of the pipe, the outer peripheral chamfering portions 3 and 3 formed on the outer peripheral surface 31E of the pipe end portions 31a and 31b following the respective pipe end surfaces 31A and 31B are provided. The outer peripheral chamfered portions 3 and 3 are formed by, for example, cutting (machine tool) in the same manner as described with reference to FIG.
The joint pipe main body 31 is formed by removing the zinc plating film M from the pipe outer peripheral surfaces 31E of the pipe end portions 31a and 31b following the outer peripheral chamfered portions 3 and 3, as described with reference to FIG. It has 4 and 4. The pipe end outer peripheral surface portions 4 and 4 have a non-plating width h along the pipe center line a of the joint pipe main body 31, and are formed by, for example, grinding (grinding machine Y) in the same manner as described with reference to FIG. ..
In the pipe joint X of FIG. 13, the pipe end surface 31A of the joint pipe body 31 is abutted against the pipe end surface 81A of the metal pipe Z, and the joint pipe body 31 is connected to the metal pipe Z by welding, as described with reference to FIG. connect.

In FIG. 14, the pipe fitting X is a tee pipe fitting. As shown in FIG. 14, the pipe joint X includes a metal (for example, carbon steel) joint pipe main body 41.
The joint pipe main body 41 has a cylindrical horizontal pipe 45 and a cylindrical vertical pipe 46, and the horizontal pipe 45 and the vertical pipe 46 are integrally formed so as to be orthogonal to each other. The vertical pipe 46 communicates with the horizontal pipe 45 by opening one end of the pipe into the horizontal pipe 45.
The joint pipe main body 41 has, as described with reference to FIGS. 1 to 7, each non-plated pipe end surface 41A, 41B, 41C, non-plated outer peripheral chamfered portions 3, 3, 3, and unplated pipe end outer peripheral surface portion 4. , 4, 4 and the inner peripheral surface portion 5 of the plating. The plating inner peripheral surface portion 5 covers the entire surface of the pipe outer peripheral surface 41D excluding the non-plated outer peripheral chamfered portions 3, 3, 3 and the non-plated pipe end outer peripheral surface portions 4, 4, 4 and the pipe inner peripheral surface 41E with the zinc plating film M. Is formed.

In the pipe joint X of FIG. 14, as described with reference to FIG. 8, the pipe end surfaces 41A and 41B of the horizontal pipe 45, the pipe end surfaces 41C of the vertical pipe 46, the pipe outer peripheral surface 41D and the pipe inner peripheral surfaces of the pipes 45 and 46. It has a joint pipe body 41 in which the entire surface of the pipe of 41E is coated with a zinc plating film M.
The joint pipe body 41 in which the entire surface of the pipe is covered with the galvanized film M is a pipe that continues from the pipe end surfaces 41A, 41B, 41C to the galvanized film M and each pipe end surface 41A, 41B, 41C, as described with reference to FIG. While removing the galvanized film M from the pipe outer peripheral surface 41F of the end portions 41a, 41b, 41c, the outer periphery formed on the pipe outer peripheral surface 41F of the pipe end portions 41a, 41b, 41c following the pipe end surfaces 41A, 41B, 41C. It has chamfering portions 3, 3 and 3. The outer peripheral chamfered portions 3, 3 and 3 are formed by, for example, cutting (machine tool) in the same manner as described with reference to FIG.
The joint pipe main body 41 is formed by removing the zinc plating film M from the pipe outer peripheral surfaces 41F of the pipe end portions 41a, 41b, 41c following the outer peripheral chamfered portions 3, 3 and 3, as described with reference to FIG. It has 4, 4, and 4 outer peripheral surface portions of the pipe end. The pipe end outer peripheral surface portions 4, 4, and 4 have a non-plating width h along the pipe center line a of each pipe 45, 46 of the joint pipe main body 41, and are, for example, ground (for example) in the same manner as described with reference to FIG. It is formed by a grinding machine Y).
In the pipe joint X of FIG. 14, the pipe end surface 41A of the joint pipe body 41 is abutted against the pipe end surface 81A of the metal pipe Z, and the joint pipe body 41 is connected to the metal pipe Z by welding, as described with reference to FIG. connect.

In FIG. 15, the pipe fitting X is a cap. As shown in FIG. 15, the pipe joint X includes a metal (for example, carbon steel) joint pipe main body 51.
The joint pipe main body 51 is formed in a hemispherical shape with one end open and the other end closed. The joint pipe main body 51 has an unplated pipe end surface 51A, a non-plated outer peripheral chamfered portion 3, a non-plated pipe end outer peripheral surface portion 4, and plating, as described with reference to FIGS. 1 to 7 (joint pipe main body 1). It has an inner peripheral surface portion 5. As shown in FIG. 15, the plating inner peripheral surface portion 5 covers the entire surface of the pipe outer peripheral surface 51C excluding the non-plated outer peripheral chamfered portion 3 and the non-plated tube end outer peripheral surface portion 4 and the pipe inner peripheral surface 51D with the zinc plating film M. Is formed.

The pipe joint X of FIG. 15 includes a joint pipe main body 51 in which the entire surface of the pipe end surface 51A, the pipe outer peripheral surface 51C, and the pipe inner peripheral surface 51D is coated with a zinc plating film M, as described with reference to FIG.
The joint pipe main body 51 having the entire surface of the pipe covered with the galvanized film M is from the pipe end surface 51A to the galvanized film M and from the pipe outer peripheral surface 51E of the pipe end portion 51a following the pipe end surface 51A, as described with reference to FIG. While removing the galvanized film M, it has an outer peripheral chamfering portion 3 formed on the outer peripheral surface 51E of the pipe end portion 51a following the pipe end surface 51A. The outer peripheral chamfered portion 3 is formed by, for example, cutting (machine tool) in the same manner as described with reference to FIG.
The joint pipe main body 51 has a pipe end outer peripheral surface portion 4 formed by removing the zinc plating film M from the pipe outer peripheral surface 51E of the pipe end portion 51a following the outer peripheral chamfered portion 3, as described with reference to FIG. The pipe end outer peripheral surface portion 4 has a non-plating width h along the pipe center line a of the joint pipe main body 51, and is formed by grinding in the same manner as described with reference to FIG.
In the pipe joint X of FIG. 15, the pipe end surface 51A of the joint pipe body 51 is abutted against the pipe end surface 81A of the metal pipe Z, and the joint pipe body 51 is connected to the metal pipe Z by welding, as described with reference to FIG. connect.

In addition to the pipe joints described with reference to FIGS. 1 to 15, the pipe joint X includes an elbow pipe joint with a neck, a tee pipe joint having a different diameter, an eccentric reducer pipe joint, a cross pipe joint of the same diameter, and an elbow-shaped flap joint made of carbon steel. It may be a pipe joint, a straight pipe type flap joint pipe joint made of carbon steel, or the like.

The present invention is most suitable for pipe fittings connecting metal pipes.

X Pipe joint Z Metal pipe M Zinc plating film 1 Joint pipe body 1a, 1b Pipe end 1A, 1B Pipe end surface 1C Pipe outer peripheral surface 1D Pipe inner peripheral surface 1E Pipe outer peripheral surface 3 Outer peripheral chamfering part (non-plated outer circumference) Chamfering part)
4 Outer peripheral surface of pipe end (non-plated outer peripheral surface of pipe end)
5 Inner peripheral surface of plating 81A Pipe end face (metal pipe)

Claims (2)

Metal fittings In pipe fittings that connect pipe bodies to metal pipes by welding
A carbon steel pipe in which an outer peripheral chamfering portion is not formed on the outer peripheral surface of the pipe end portion following the pipe end surface, and the entire surface of the pipe end surface of the carbon steel pipe and the outer peripheral surface of the pipe following the pipe end surface is covered with a zinc plating film. Equipped with a joint pipe body,
The metal tube has a non-plated tube end surface, a non-plated outer peripheral chamfering portion following the non-plating tube end surface, and a non-plating outer peripheral chamfering portion following the non-plating outer peripheral chamfering surface, and the non-plating outer peripheral chamfering portion. It is formed by covering the entire outer peripheral surface of the pipe with a galvanized coating, except for the portion and the outer peripheral surface of the unplated pipe end.
The joint pipe main body in which the entire surface of the pipe end surface of the carbon steel pipe and the pipe outer peripheral surface following the pipe end surface is coated with a zinc plating film is
A non-plated pipe end surface formed by removing the galvanized coating from the pipe end surface of the joint pipe body by cutting and abutting against the non-plated pipe end surface of the metal pipe.
The joint pipe following the non-plated pipe end surface of the joint pipe body while removing the zinc-plated coating from the pipe outer peripheral surface of the pipe end portion of the joint pipe body following the non-plated pipe end surface of the joint pipe body by cutting. A groove formed by cutting on the outer peripheral surface of the pipe end of the main body of the metal pipe and the non-plated outer peripheral chamfering portion of the metal pipe having the unplated pipe end surface abutted against the non-plated pipe end surface of the joint pipe main body. The non-plated outer peripheral chamfered part that forms the part,
It has a non-plated pipe end outer peripheral surface portion formed by removing the zinc plating film from the pipe outer peripheral surface of the pipe end portion following the non-plated outer peripheral chamfered portion of the joint pipe main body .
Connected to the metal tube by welding along the groove
A pipe fitting characterized by that. The joint pipe main body in which the entire surface of the pipe end surface of the carbon steel pipe and the pipe outer peripheral surface following the pipe end surface is coated with a zinc plating film is
A grindstone formed on a circular plate and having the same plate width as the non-plated width is placed at a position continuous with the non-plated outer peripheral chamfering portion of the joint pipe body, and the grindstone is placed on the pipe outer peripheral surface of the rotating joint pipe main body. Is pressed to remove the galvanized coating from the outer peripheral surface of the pipe end of the joint pipe main body following the non- plated outer peripheral chamfering portion of the joint pipe main body. The pipe joint according to claim 1, wherein the pipe joint has an outer peripheral portion at the end of a plated pipe.

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