JPH06568U - Insert ring for pipe welding - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an insert ring for a welded pipe made of SUS, which can prevent oxidation generated on the inner surface of the welded portion during welding of the pipe. An annular portion 7 mounted on the inner peripheral surface between the ends of two pipes 1 and 2 made of SUS on the groove 3 side, and an outer peripheral surface 7a contacting the inner walls of the pipes 1 and 2, Outer peripheral surface 7a of the annular portion 7
A flange portion 8 formed to project outward in the center of the groove for closing the gap of the groove 3, and a flux 10 filled in an annular groove 9 formed on the inner peripheral surface of the annular portion 7. Have.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an insert ring for a welded portion of a pipe for preventing oxidation of the inner surface of the welded portion when welding SUS pipes such as a boiler.

[0002]

[Prior art]

 When welding SUS boiler pipes, if air enters the pipes, the inner surface of the weld will oxidize. Therefore, conventionally, as shown in Fig. 4, prior to welding work, the pipes were formed at the opposite ends of pipes 1 and 2. Using the gap d of the groove 3 (usually 2 to 3 mm), an inert gas such as argon gas or nitrogen gas is blown into the inside of the pipes 1 and 2 from the tip of the nozzle 4, and This gas was sealed up to the water-soluble paper 5 packed in the middle of the interior, and a back shield was provided to prevent air from entering the inside of the pipes 1 and 2.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned conventional technique, the phenomenon of air suction into the pipe and the blowing out of the inert gas from the pipe due to the atmospheric pressure difference between the pipe and the outside air occur, and the inflow of air into the pipe is completely prevented. Therefore, there is a drawback that the inner surface of the welded part is oxidized by the inflowing air and the quality of the pipe after welding is adversely affected.

The present invention has been made on the basis of such a background, and provides an insert ring for a welded pipe made of SUS, which can surely prevent oxidation on the inner surface of the welded part during pipe welding. The purpose is to do.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the present invention, an annular portion which is attached to a groove formed at an opposite end portion of a SUS pipe and an outer peripheral surface of which contacts an inner wall of the pipe, and an outer periphery of the annular portion. A ring-shaped collar portion formed to project outward toward the groove for closing the groove gap, and a flux filled in an annular groove formed on the inner peripheral surface of the annular portion. The present invention provides an insert ring for SUS pipe welds.

[0006]

[Action]

 If the groove portion is, for example, TIG welded, the insert ring is melted and integrated with the pipe. In this case, the flux filling the annular groove prevents oxidation of the inner surface of the weld.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. It should be noted that parts that are the same as or can be regarded as the same as those in the conventional example are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a front view of two pipes in which an insert ring is mounted from the inside, FIG. 2 is a perspective view of the insert ring in a portion A of FIG. 1, and FIG. 3 is a longitudinal sectional view of a portion A of FIG. Is.

An insert ring 6 made of SUS is attached from the inside to the gap of the groove 3 formed at the facing portion of the two pipes 1 and 2 to be welded. As shown in FIGS. 2 and 3, the insert ring 6 has an annular shape including an outer peripheral surface 7a extending in the vertical direction and an arcuate portion 7b bulging toward the inner surface, which contacts the inner walls 1a, 2a of the pipes 1, 2. Part 7, an annular flange 8 projecting outward from the center of the outer peripheral surface 7a, and a flux 10 filled in an annular groove 9 formed in the center of the arcuate part 7b opposite to the flange 8. It is composed of.

The insert ring 6 is fitted inside the gap between the ends of the pipes 1 and 2, with the flange 8 fitted in the gap of the groove 3 from the inside.

In this state, when TIG welding is performed with the TIG welding electrode 11 and the filler rod 12 facing the groove 3 as shown in FIG. 3, the pipes 1 and 2 are connected by welding. , The insert ring 6 is heated and melted by heat, and integrated with the pipes 1 and 2. At this time, since the welded parts inside the pipes 1 and 2 in the groove 3 are sealed by the flux 10, the oxidation of the welded parts is surely prevented. Further, the collar portion 8 facilitates the work of aligning the groove 3.

[0012]

[Effect of device]

 As described above, according to the present invention, the annular groove is filled with the flux, and the annular collar portion projecting from the annular portion is attached to the inner peripheral surface of the groove of the SUS pipe. The SUS insert ring, which is inserted from the inside of the flange so as to close the gap of the groove, can reliably prevent oxidation on the inner surface of the weld during pipe welding, It is possible to easily perform the work of matching.

[Brief description of drawings]

FIG. 1 is a front view of two pipes with an insert ring according to the present invention mounted from the inside.

FIG. 2 is a perspective view of an insert ring of part A of FIG.

FIG. 3 is a longitudinal sectional view of an insert ring showing an enlarged portion A of FIG.

FIG. 4 is an explanatory view showing a state of a back shield during pipe welding according to a conventional example.

[Explanation of symbols]

 1, 2 Pipes 1a, 2a Inner wall 3 Groove 6 Insert ring 7 Annular part 7a Outer peripheral surface 8 Collar part 9 Annular groove 10 Flux

Claims (1)

[Scope of utility model registration request] 1. An annular portion, which is attached to a groove formed at opposite ends of a SUS pipe, and whose outer peripheral surface is in contact with the inner wall of the pipe, and an outwardly projecting outer periphery of the annular portion. An insert ring for a pipe welding part made of SUS, which is provided with an annular collar part formed to close the gap of the groove and a flux filled in an annular groove formed on the inner peripheral surface of the annular part. .