JPH0413648B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for connecting piping of a pressure vessel, and in particular to a method for connecting piping of a pressure vessel, in which the piping is connected extremely easily by cutting at a cutting groove. Concerning piping connection methods.

[Technical background of the invention]

Generally, pressure tests such as pressure resistance tests and leak tests are required for pressure vessels before connecting piping.

Conventionally, as shown in FIG. 1, piping joints 2, 2 are provided at a piping connection portion of a pressure vessel 1 so as to protrude from the pressure vessel 1 by a predetermined length.
Piping 3, 3 is connected to 2.
When performing a pressure test on the pressure vessel 1,
As shown in FIGS. 2 and 3, a blind cover 4 is welded and fixed to the tip opening of the piping joint 2.
After closing the pressure vessel 1, the pressure inside the pressure vessel 1 is raised or lowered to a predetermined value and a test is performed. In this case, the blind lid 4 is often provided with a pressure outlet 4a, and a pressure measuring device 5 is connected to the pressure outlet 4a to measure the pressure inside the pressure vessel 1.

Furthermore, after the pressure test is completed, the pipe joint 2 is cut along the dashed line in the figure, the blind cover 4 is removed, the cut end of the pipe joint 2 is shaped into a welding groove, and the pipe 3 is welded. I was trying to connect it by

[Problems with background technology]

However, groove shaping performed in this manner is extremely time-consuming. In particular, when the pipe joint 2 has a thick wall, the cutting operation itself takes time, and furthermore, the subsequent machining and groove formation are extremely time-consuming. In addition, pressure vessel 1
Depending on the installation location, machining may not be possible, and in such cases it must be done manually, making it difficult to shape the bevel of thick-walled pipes. Another problem was that during cutting and beveling, excessive force was applied to the weld between the pressure vessel and the pipe joint, causing damage to the weld.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure vessel piping connection method that allows groove shaping after a pressure test to be performed extremely easily and quickly.

[Summary of the invention]

In order to achieve the above object, the present invention forms an annular groove in the cut portion of a pipe joint, and slopes the side surfaces of this annular groove, so that when the pipe joint is cut at the bottom of the groove, the cut end remains open for welding. It is characterized in that a tip is formed and the pipe is welded to this weld groove.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIGS. 4 and 5, a concave groove 12 is previously formed in an annular shape on the outer periphery of the distal end of a tubular piping joint 11 that is provided to protrude a predetermined length from a pressure vessel (not shown). ing. This groove 12 is provided a predetermined distance from the tip end inward, that is, closer to the pressure vessel side, and the side surface 12a of this groove 12 on the pressure vessel side is formed to be inclined at a predetermined angle. Note that rough machining (▽ symbol) is sufficient for the finishing accuracy of each surface of the groove 12.

When performing a pressure test on a pressure vessel,
A blind cover 13 is fixed to the tip opening of the piping joint 11 by welding to seal the pressure vessel, and the pressure inside the pressure vessel is increased or evacuated. Further, the pressure inside the pressure vessel is measured by connecting a pressure measuring device 14 to a pressure outlet 13a provided in the blind lid 13.

After the pressure test of the pressure vessel is performed in this way, as shown in FIGS. 6 and 7, the pipe joint 11 is moved almost vertically along the pipe axis at the bottom of the groove 12 on the pressure vessel side. The blind cover 13 is removed together with the tip of the pipe joint 11. As shown in FIG. 7, the remaining pipe end of the pipe fitting 11 has a bevel formed at the same time as cutting, and the end surface 11a is simply lightly ground with a grinder or sanded. Piping can be immediately welded and connected.

Piping connections are made as shown in FIG. That is, the pipe joint 1 whose groove has been shaped as described above
The pipe end 15a of the pipe 15 is butted against the pipe 1, and the gap formed between the two is welded to connect.
At this time, if the piping joint 11 and the piping 15 are brought into contact with each other through the insert ring 16 as shown in this figure, it is possible to ensure that they are in contact with each other without wobbling, and it is also possible to easily complete the process. Can carry out Uranami welding.

The sloped surface of the concave groove 12 of the pipe joint 11 can be formed into a curved shape or other shape convenient for welding.

〔Effect of the invention〕

As described above, the present invention forms a circumferential concave groove in the cut portion of a pipe joint, and when the pipe joint is cut at the groove bottom of the concave groove, the cut end directly forms a welding groove. Because of this, even when the pipe joint has a thick wall, it is possible to cut the pipe joint at the bottom of the thin-walled groove, making the cutting work very efficient, and after cutting, it is possible to cut the pipe joint at the bottom of the thin groove. There is almost no need to perform troublesome groove shaping work, and piping can be welded immediately. Therefore, even in cases where machining is not possible, piping connection work can be performed extremely easily and efficiently.

[Brief explanation of drawings]

Figure 1 is a side view of a general pressure vessel, Figure 2 is a partial sectional view showing an example of a conventional piping joint, Figure 3 is a partial sectional view showing another example of a conventional piping joint, and Figure 4 is a partial sectional view showing another example of a conventional piping joint.
5 is an enlarged view of part A in FIG. 4, FIG. 6 is a partial sectional view showing the pipe joint cut away, and FIG.
The figure is an enlarged view of part B in FIG. 6, and FIG. 8 is a partial sectional view showing a case where the pipe is welded to the pipe joint. 11... Piping joint, 12... Concave groove, 13... Blind lid.

Claims (1)

[Claims] 1. A pressure test is performed on the pressure vessel by closing a piping joint provided so as to protrude a predetermined length from the pressure vessel with a blind lid, and then cutting the piping joint, removing the blind lid, and inserting a pipe into the cut tip. In a pressure vessel piping connection method in which piping is connected, on the outer periphery of the piping joint closed by the blind lid,
A concave groove extending in the circumferential direction is formed by tilting the side surface of the pressure vessel at a predetermined angle so as to form a welding groove facing the end of the pipe connected to the pipe joint, and the pressure test of the pressure vessel is performed. Later, the area extending over the blind cover is removed by cutting at the bottom of the groove so that a thin root portion that slightly protrudes in the axial direction remains at the tip of the weld groove forming portion of the pipe joint,
A method for connecting piping for a pressure vessel, characterized in that the root portion of the welding groove and the root portion of the welding groove of the mating piping to be connected to the piping joint are then butted against each other and welded.