JPS5850192A - Butt welding method for tube - Google Patents

Abstract

PURPOSE:To improve gas purging effect and to obtain a weld joint with high quality by placing balloons having small holes on the butted side of tubes and sealing the tube with gas discharged from the small holes while supplying pressure gas to contact the balloons with inside of tubes. CONSTITUTION:Rubber balloons 5, 5 having minute holes 5a are put in tubes 1, 1. After fitting grooves 1a, inert gas is let flow in from holes 6 to inflate balloons 5, and the balloons are brought into close contact with inner walls of base metals 1, 1. The insert gas flown into the balloons 5 goes out from holes 5a and replaces the atmosphere in the tubes including the butted part with inert gas in a short time. Under this condition, penetration welding of root part of the grooves 1a is performed. At this time, a small part is left unwelded, and after taking out the balloons 5, the part is filled using a filler rod etc. By this way, back purging can be performed without replacing the whole piping structure with inert gas and without sealing.

Description

[Detailed Description of the Invention] Conventionally, a method for forming a back bead using 1s of N tip in butt welding, such as by butt welding, is to space the roots of the grooves and open the grooves. There is a method of forming an a-wave by contacting lfi from the & side. In this case, in order to prevent oxidation on the top surface near the bath contact area, welding is performed while flowing an inert gas such as argon gas inside the piping in order to prevent oxidation of the fcjl wave peak. This is commonly referred to as the bank purge method. FIG. 1 shows an example of the state before welding of a conventional butt welding method for pipes using the bank purge method.

In this case, (υ is the base material, (1a) is the V-shaped groove provided by the base material, (lb) is the root surface of the groove (l is the root spacing between the root surfaces, (4 ) is the blind cover for the pack purge gas attached to one end of the pipe, (2) is the cover for the bank purge gas inlet attached to the other end of the pipe, and (3) is the cover for the bank purge gas inlet attached to the other end of the pipe.
2) shows the hose for the back purge gas inlet.

If the conventional method is used, put a blind cover (4) on one end of the pipe and close the other end)
It is necessary to use the rubber purge gas inlet hose (31W =) to inject inert gas and replace the entire atmosphere inside the piping, including the butt bath compensation joint, with an inert gas, creating an inert gas atmosphere. After the inside of the pipe reaches the inhospitable dust atmosphere, the root surface (lb) of the groove (la) is welded using the arc welding method to form a back wave.During this time, the inside of the pipe remains in its original state. Unfortunately, it is necessary to allow inert gas to flow into the metal.In this case, if the purity of the inert gas atmosphere inside the pipe is poor, butt welding is necessary. The inner surface of the joint joint may be oxidized due to the heat of welding, or the oxidation of the agricultural drum heat may cause bead formation.

However, many of the conventional installation structures are long, and replacing the atmosphere inside the pipes, including the butt welds S, with an inert gas is difficult if the internal volume is large and a large amount of inert gas is required. However, there are many times when it is difficult to understand. It is known that it is economically unwise to replace such a large internal volume with an inert atmosphere. If the optical sound cannot be replaced, uneven formation of <1m beads as mentioned above will occur, which will not only cause a noticeable deterioration in quality, but also cause internal Ifl oxidation to occur in the V layer of the structure. This has disadvantages in that it causes clogging of filters in oil and air pipes, etc., and undesirably lowers or damages the rock I2 of the piping structure.

The present invention has been made to address the above-mentioned drawbacks, and there is no need to treat the entire interior of the pipe with inert gas, and the internal volume of the inert gas seal is reduced, ensuring that only the vicinity of the butt joint is filled with inert gas. It is an object of the present invention to provide a method for butt bath welding with gas purge effect.

The present invention will be described below in Figure 1Mo4.

In Figure 142, (5) is a rubber balloon, (6) is a rubber balloon (
This is a hose for supplying inert gas to 51. The rubber balloon (5) has a small height (5m).

First, match the grooves immediately as shown in Figure 2. T! At this time, after placing the IU Kocom balloons (5j, (51) in each of the chamber base materials (1) and (1) in advance, prepare the grooves shown in Fig. 2). It flows into the inert dregs 1 from the mating hose 16), inflates a rubber balloon (5) (5J) and forms a dense layer on the base material (13, V3# of (1)).

However, because there is a small person (5a) on the rubber boat (5), it is cloudy, and the non-foam gas flowing into the rubber balloon circle is forced to escape through that person. Therefore, even if the non-oily gas flows in and falls, the rubber balloon (5 + l) will continue to be exposed to the inside of the base material without breaking or loosening. 5) In a large hole with -0 machine, rt <, so that the internal pressure that is enough to push the rubber balloon against the inner wall of the base material is -0 or 0), and the internal pressure of 6C is above the treatment. It is necessary to design it so that it is easy to use. Also, A-f+ on the rubber balloon (5)
The oily gas #1jll rubber balloon 151 bursts due to excessive force and does not form a dense layer with the inner wall of the base material fA 4
a It must not be too small. If you hang it like this, it will become a com balloon (5- is a castle within the ration) and will be a 21m1 rubber balloon (
5], I was deeply saddened by the fact that I was secretly taken prisoner.

At this time, the non-tIX gas is likely to be emitted by the nine people (6a) provided in the rubber
It is replaced by the 7ilS basin at the foot of the gas. After that, the corpse (
Perform the root acid urazozokubutsu of la). However, in this part, the inert gas is used to stop the rubber balloon (6p) from inside the chamber and there is a device for extracting it from the outside. Public funds are used to cook a small portion of the amount that can be taken out without bathing.This portion is buried by using a rubber balloon (5i, good.

As mentioned above, when trying to compensate by bathing, there is no need to seal the entire interior of the structure with inert gas.
The back barge is rr it. In addition, it is easy to leave the dead scum.
Rabi lko seal-fru Tani Shin is also small and swells, so 11 more small clean gas Naohiro enters.

As a detailed structure, 11 out of 11 [l] will definitely prevent Europeanization, and will also ensure the best quality of the structure. Got a hand n4. When does it come into play?

In addition, it is necessary to purchase materials for the rubber-like lid (6).
Rubber does not require any treatment, and the young trees of the present invention can be used in anything that is placed under gas pressure. Immediately put on the map of Yotamasu 2 to kIk+1: The sandwiched rubber balloon (
5) - Even if there is no hole (5a) and the number of balloons in the 10,000-piece balloon hole is open, you can still get an inventive rice effect.

In addition to the above-mentioned @tsuboko, which is often lost due to uninventiveness, and the vulgarity of the back barge method using small inn dregs, it is necessary to carry out the necessary inheritance. : Only part of F is Kazumi Kumofu@Kyoukasu wIt Hong and Kumoko stickers are made%
High-quality bath dressing - the benefits of being able to use it by hand.

,4. Figure 1 is a diagram showing 14P4 of the foreshadowing before the bathing priest when performing the common method of butting defective rice. FIG. 2 is a t1mT diagram of nine actual examples of the shape of the welding surface when performing the butt welding method of the present invention.

l...base material, la...bevel, ib
...Root surface, 2...Thread, 3...Hose
4...ki lid, S-...balloon °6...hose, 5a...person.

Claims (1)

[Claims] Inside the abutting part of the IIR, a balloon communicating with the inert gas supply device housing and having a small hole T4 in the abutting part IMII is placed, When the gas is inflated by supplying pressure gas from the ink and inscribed in the abutment, the scum emitted from the abutment part is removed from the atmospheric force by the scum released from the abutment part, and then the bath is left over. This method of butt bathing is characterized by the following.