JPS6234630A - Lining pipe and its manufacture - Google Patents

Abstract

PURPOSE:To prevent a trouble from being generated due to a thermal stress by providing a spiral groove on the inner surface of a main pipe, bringing into a lining blank pipe contact with to the inner surface of the main pipe, and absorbing a difference of coefficients of thermal expansion of the main pipe and the lining pipe. CONSTITUTION:A spiral groove 11' is formed on the inner surface of a main pipe 11 by a roller working, etc. Subsequently, a lining blank pipe 12 of a thin wall made of Ti, Zr, etc. is inserted into the main pipe which has formed the groove 11' on the inner surface. To this lining blank pipe 12, a stress exceeding a yield point of the thin wall lining blank pipe 12 is applied by operating an explosion, a hydraulic pressure, etc., and a lining pipe 13 is brought into contact with each other and formed on the inner surface of the main pipe 11 and in the groove 11'. Since the inner surface of the lining pipe 13 is brought to a groove working and formed in a shape of a waveform, a thermal expansion difference of a lining material such as Ti, Zr, etc. of a corrosion resisting material, and a base material is absorbed. In this way, a thermal stress load to a lining pipe end part is reduced, and a lining pipe of a long service life is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a method for manufacturing a lined pipe, and a method for manufacturing a lined pipe that does not cause troubles due to thermal stress even if the thermal expansion coefficients of the main pipe and the lining material are different. Regarding the manufacturing method.

[Prior Art 1] Conventionally, pipes or piping lined with high-grade corrosion-resistant materials such as Ti, Zr, Ta, Nb, V, and alloys thereof have been manufactured by various methods.

For example, a typical example of a conventional lining pipe has the structure shown in FIG. 3, in which Ti, Ti, Three linings made of Zr, Ta, etc. are attached individually, and the ends of the linings 3 are fixed to a collar plate 4 provided on the 7 flange 2 by welding 5.

Therefore, the thermal expansion coefficient of Ti%Zr, Ta, etc. of the lining material is Ti=9. OXl 0-'/'C1Zr=5
．． 8X 10-'/"C1Ta = 6X10" 67℃, which on the other hand is about 1 of the coefficient of thermal expansion of the carbon steel used for the main tube.
It is significantly lower than 2X10'''6/℃, and as a result,
During operation, high thermal stress is generated due to the difference in thermal expansion between the main tube and the lining material due to the difference in thermal expansion coefficients.

Therefore, stress is concentrated particularly at the welded portion 5 in FIG. 3 of the flange portion of the tube end 7, causing problems such as cracking. The higher the temperature during operation and the longer the pipe, the shorter the life of the welded portion 5.

[Problems to be Solved by the Invention] The present invention solves the problems described above in conventional lined pipes manufactured using materials such as Ti, Zr, and Ta as lining materials of corrosion-resistant materials. In view of the occurrence of
Even if there is a large difference between the coefficient of thermal expansion of the main pipe and the coefficient of thermal expansion of the main pipe, we have developed a lining pipe that can be used for a long period of time without any trouble during high-temperature operation, and a method for manufacturing the same.

[Means for Solving the Problems 1] The lining tube and the manufacturing method thereof according to the present invention are characterized by: (1) having a spiral groove on the inner surface of the main tube, and making the lining tube closely adhere to the inner surface; The first lined pipe characterized by
(2) forming a spiral groove on the inner surface of the main pipe, then inserting a thin-walled lining pipe made of a corrosion-resistant material into the main pipe;
The second invention is a method for producing a lined pipe characterized in that the thin-walled lined pipe is brought into close contact with the inner surface of the main pipe by applying an explosion or hydraulic pressure to the thin-walled pipe.

The lining pipe and the manufacturing method thereof according to the present invention will be explained in detail below.

A lining pipe and a method for manufacturing the same according to the present invention will be explained using examples shown in FIGS. 1 and 2.

First, the inner surface (or outer surface may be used) of the main tube 11.

This will be discussed later. ) is formed with a spiral groove 11' by roller processing or the like.

Next, a thin-walled lining tube 1 made of Ti, Zr, Ta, etc.
2 is inserted into the main tube 11 which has a groove 11' formed on its inner surface.

Then, the thin-walled lining tube 12 is subjected to an explosion, hydraulic pressure, etc. is applied to the lining tube 12, so that the thin-walled lining tube 12 yields, and the lining tube 13 is tightly molded into the inner surface of the main tube 1 and inside the groove 11' by applying a stress that exceeds its own. do. In this case, it is natural that the pressure should not exceed the yield point of the main tube l.

The lining pipe and the method for manufacturing the same according to the present invention are characterized in that the inner surface of the lining pipe is grooved and formed into a corrugated shape, so that heat between the lining material such as a corrosion-resistant material such as Ti, Zr, or Ta and the base material can be reduced. The differential expansion is absorbed, thus reducing the thermal stress load on the lined tube ends and producing a lined tube with a long life.

In addition, by increasing the groove depth and groove pitch according to the operating temperature, it can be used at various high temperatures.Furthermore, since the problem of thermal stress has been solved, it is now possible to use long lined raw pipes. Become.

In addition to forming grooves on the inner surface of the main tube as described above, grooves are formed on the inner surface of the main tube 11 by roller machining from the outside of the main tube 11, as shown in FIG. Ti, Zr,
It is also possible to manufacture a lined pipe by inserting a lined pipe made of a corrosion-resistant material such as Ta and closely fixing the lined pipe to the inner surface of the main pipe 11 by explosive pressure welding or the like to form the lining 13. In this case as well, the difference in thermal expansion can be absorbed as in the above explanation, and the thermal stress on the end of the lining tube can be reduced, and it can be used at various high temperatures by changing the groove depth, pitch, etc. It is something that can be done.

[Effects of the Invention] As explained above, since the lining pipe and the manufacturing method thereof according to the present invention have the above configuration, the lining pipe is formed into a corrugated shape, so that thermal expansion between the main pipe and the lining pipe is reduced. It has the excellent effect of being able to manufacture a lining tube that can absorb the difference in coefficients and further reduce thermal stress on the end of the lining tube.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams for explaining the lining manufacturing method according to the present invention, and FIG. 3 is a schematic diagram of a lining pipe manufactured by a conventional manufacturing method. 1.11...Main pipe, 3,13...Lining, 11'
...Groove, 12...Lining raw pipe. Sai 1z Spear 2

Claims (2)

[Claims] (1) A lined pipe characterized by having a spiral groove on the inner surface of the main pipe, and having a lining pipe closely attached to the inner surface. (2) Machining a spiral groove on the inner surface of the main pipe, then inserting a thin-walled lining pipe made of corrosion-resistant material into the main pipe,
A method for manufacturing a lined pipe, characterized in that the thin-walled lined raw pipe is brought into close contact with the inner surface of the main pipe by applying an explosion, hydraulic pressure, or the like.