JPH1047557A - Clearance setting method and member for welded pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a separation space accurately by inserting a clearance setting member formed in a thickness in response to the set space by a raw material decomposed by a prescribed temperature in the connection pipe insertion hole of a coupling member and welding and fixing the inserted connection pipe to the coupling member. SOLUTION: When a setting space X is installed between the end surface 21 of a reaction pipe 20 and the facing surface 34 of a coupling 30 and the reaction pipe 20 is welded and fixed to the coupling 30, at first, a spacer member as a clearance setting member is inserted in the insertion hole 33 of the coupling 30. Thereafter, the end surface 21 of the reaction pipe 20 is contacted with the spacer member and the corner part between its outer surface and the outer end surface 33 of the coupling 30 is welded. Meantime, the spacer member is formed by a raw material decomposed at the temperature below the temperature of a fluid streamed at the operation time of a pipe road structure and heated and decomposed by the flow of a high temperature fluid and the end surface 21 of the connection pipe 20 and the facing surface 34 of the coupling member 30 are formed in a state facing each other at the adequate separation distance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint structure of a pipe structure through which a high-temperature fluid flows, when a joining pipe is joined to a coupling member fixed to the outer surface of a joined pipe member by welding. The present invention relates to a clearance setting method and a clearance setting member for a welded pipe joint for setting a predetermined interval between an end surface of a joining pipe and an opposing surface of a coupling member.

[0002]

2. Description of the Related Art Conventionally, in a pipeline structure such as a plant, as shown in FIG.
As shown in FIG. 7 which is a cross-sectional view taken along the line AA in FIG. 6, a cup fixed to the outer surface of the pipe member 50 to be connected is used as a pipe joint structure for branching a small-diameter pipe line (joined pipe 60) from FIG. There is a ring member 70 in which the joint pipe 60 is fitted and fixed by welding.

The coupling member 70 has a fitting hole 71 formed on the outer end side to which the joining tube 60 can be fitted, and a passage 72 corresponding to the inner diameter of the joining tube 60 on the base end side. The base end side is in contact with the outer surface of the pipe member 50 to be joined, and the periphery thereof is fixed by welding.

[0004] The joining pipe 60 is fitted into the fitting hole 71 of the coupling member 70, and the end face 61 abuts on the stepped portion (opposed surface 73) of the fitting hole 71 and the passage 72. Are welded (welded portion: C) over the entire circumference and joined.

[0005]

By the way, in a pipe structure of a plant such as a steam reforming furnace through which a high-temperature fluid flows, the pipe joint structure as described above is accompanied by a rise in temperature due to the fluid during operation of the plant. Joint tube 6 due to thermal expansion
0, the end face 61 is in contact with the opposing face 73 of the coupling member 70 as described above, and a portion on the tip side from the welding position with the coupling member 61: B
There is a possibility that a stress is generated in the welded portion C due to the elongation of the steel, leading to breakage.

For this reason, the end face 61 of the joining pipe 60 is fixed by welding in a state of being separated from the facing face 73 of the coupling member 70 by a predetermined distance. As described above, the welding operation in a state where the end face 61 of the joining pipe 60 is separated from the facing face 73 of the coupling member 70 by a predetermined distance is performed until the joining face 60 abuts on the facing face 73 of the coupling member 70. This is performed by inserting a marking line at a position corresponding to the outer end surface 64 of the coupling member 70 on the outer surface, and floating the outer surface 64 of the coupling member 70 by a predetermined amount using the marking line as a mark.

However, such a welding operation is extremely troublesome, and it is difficult to accurately set the distance between the end surface 61 of the joining pipe 60 and the facing surface 73 of the coupling member 70. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and can easily perform a welding operation of a joined pipe in a state where an end face is separated from an opposing face of a coupling member by a predetermined distance. Moreover, it is an object of the present invention to provide a clearance setting method and a clearance setting member for a welded pipe joint that can accurately set the separation interval.

[0009]

A method for setting the clearance of a welded pipe joint according to the present invention, which achieves the above object, comprises fixing a pipe joint structure of a pipe structure through which a high-temperature fluid flows to an outer surface of a pipe member to be joined. A method of welding and fixing a joining pipe to a coupled member having a predetermined interval between an end face thereof and an opposing face of the coupling member, wherein the joining pipe is provided in a joint pipe fitting hole of the coupling member. After inserting a clearance setting member formed at a thickness corresponding to the set interval by a material that decomposes at a temperature equal to or lower than the temperature of the high-temperature fluid, the joining pipe is inserted, and the end face of the joining pipe and the cup are inserted. The joint pipe and the coupling member are welded and fixed in a state where the clearance setting member is interposed between the ring and the opposed surface of the ring.

[0010] The clearance setting member is decomposed by the temperature rise due to the fluid during the operation of the plant, and a gap corresponding to the clearance setting member is formed between the joint pipe and the facing surface of the coupling.

Further, the clearance setting member according to the present invention is a pipe joint for a pipe structure in which a high-temperature fluid flows, the pipe being joined to a coupling member fixed to an outer surface of a pipe member to be joined by welding. In the structure, a predetermined interval is set between an end surface of the joining pipe and an opposing surface of the coupling member, and the coupling member is joined by a material that decomposes at a temperature equal to or lower than the temperature of the high-temperature fluid. An outer shape that can be inserted into the pipe fitting hole, formed to have a thickness corresponding to a set interval between the end face of the joining pipe and the facing face of the coupling member, and facing the joining pipe and the facing face of the coupling. And a gap between the two is set to the thickness.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a state in which a method for setting a clearance of a welded pipe joint according to the present invention is applied to a manifold 10 as a pipe to be joined and a reaction pipe 20 as a joined pipe.
FIG. 3 is a cross-sectional view of a welded pipe joint portion to which a reaction tube 20 is fixed by welding to a coupling 30 as a coupling member fixed to the outer surface of the manifold 10 by welding.

The coupling 30 has a reaction tube 20 at its outer end.
Is formed, and a passage 32 having the same diameter as the inside diameter of the reaction tube 20 is formed at the base end, and the periphery thereof is in a state where the base end is in contact with the outer surface of the manifold 10. Fixed by welding.

A through hole 11 having the same diameter as the passage 32 of the coupling 30 is formed on an outer wall of a portion of the manifold 10 corresponding to the coupling 20.

The reaction tube 20 is inserted into the fitting hole 32 of the coupling 30, and the outer surface thereof is welded to the outer end surface 33 of the coupling 30, whereby the reaction tube 20 is joined to the manifold 10.

The end face 21 of the reaction tube 20 and the coupling 3
The step (opposing surface 34) formed by the fitting hole 31 and the passage 32 is opposed to each other, and the reaction tube 2 is heated between the two by the flow of the high-temperature fluid during operation of the pipe structure.
An interval (set interval: X) is set so as not to hinder elongation due to thermal expansion of 0.

As described above, in order to provide the set distance X between the end surface 21 of the reaction tube 20 and the facing surface 34 of the coupling 30 and fix the reaction tube 20 to the coupling 30 by welding,
In the setting method according to the present invention, first, a spacer member 40 as a flat washer-shaped clearance setting member whose plan view is shown in FIG. 3A and whose sectional view is shown in FIG. 3 and 4, and then the end face 21 of the reaction tube 20 is brought into contact with the spacer member 40 as shown in FIG. Weld the corners.

As described above, the reaction tube 20 is welded and fixed to the coupling 30 in a state where the end surface 21 of the reaction tube 20 is in contact with the spacer member 40, so that the operation such as complicated positioning is not required. Can perform welding work. Further, an end face 21 of the reaction tube 20 is coupled to the coupling 30.
Is accurately set by the thickness of the spacer member 40.

Here, the spacer member 40 is decomposed at a temperature equal to or lower than the temperature of the fluid flowing during operation of the pipe structure, and is made of a material that does not affect the fluid. It has an outer shape that can be inserted above, and is formed in a disk shape having a thickness equal to X: a set interval between the end surface 21 of the reaction tube 20 and the facing surface 34 of the coupling 30, and the center thereof is substantially equal to the passage 32. It is open with a diameter.

Such a spacer member 40 remains at this position even after the reaction tube 20 is joined, but is heated and decomposed due to the flow of a high-temperature fluid during operation of the pipe structure, and the thermal expansion of the reaction tube 20 is caused. A gap (a set interval: X) that does not hinder the elongation due to is generated, and the state shown in FIG. 1 is obtained.

As a material of the spacer member 40, any material can be used as long as it decomposes at a temperature lower than the fluid temperature and reduces the volume and does not affect the fluid, but if the fluid temperature is, for example, about 500 degrees Celsius. A polymer compound such as paper or polyethylene that carbonizes at 300 degrees Celsius can be considered, and wax and the like that can be melted at a lower temperature can also be used.

[0022]

As described above, according to the method and the member for setting the clearance of the welded pipe joint according to the present invention, the end face is brought into contact with the member for setting the clearance inserted in the joint hole of the coupling. Since the joint pipe is welded to the coupling member in the state of being in contact, the welding operation of the joint pipe can be performed extremely easily, and the clearance setting member is decomposed by heat of the fluid flowing through the pipe structure. In order to create a corresponding gap, the distance between the end face of the joint pipe and the opposing face of the coupling member can be accurately set.

[Brief description of the drawings]

FIG. 1 is a sectional view of an example of a welded pipe joint portion to which a method for setting a clearance of a welded pipe joint according to the present invention is applied.

FIG. 2 shows a spacer member, (A) is a plan view,
(B) is a sectional view.

FIG. 3 is a view showing a state in which a spacer member is inserted into a coupling member.

FIG. 4 is an explanatory diagram of a joining pipe joining step.

FIG. 5 is a view showing a state at the end of a joining pipe joining step.

FIG. 6 is a perspective view of a pipeline structure provided with a welded pipe joint.

FIG. 7 is a sectional view of a welded pipe joint portion corresponding to a section taken along line AA of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Manifold (joined pipe member) 20 Reaction tube (joined pipe) 21 End face 30 Coupling (coupling member) 31 Fitting hole (joining pipe fitting hole) 34 Opposite surface 40 Spacer member (clearance setting member)

Claims (2)

[Claims] In a pipe joint structure of a pipe structure through which a high-temperature fluid flows, a coupling member fixed to an outer surface of a pipe member to be joined is connected to an end face of the coupling pipe and an opposing surface of the coupling member. A method of welding and fixing with a predetermined interval between the joints, wherein a thickness corresponding to a set interval by a material that decomposes at a temperature equal to or lower than the temperature of the high-temperature fluid in the joint pipe fitting hole of the coupling member. After inserting the clearance setting member formed in the above, the joining tube is inserted, and the joining is performed in a state where the clearance setting member is interposed between the end surface of the joining tube and the facing surface of the coupling member. A clearance setting method for a welded pipe joint, wherein a pipe and the coupling member are fixed by welding. 2. A pipe joint structure for a pipe structure through which a high-temperature fluid flows, wherein the pipe is joined to a coupling member fixed to an outer surface of a pipe member to be joined by welding. A predetermined interval is set between the coupling member and the facing surface, and the material is decomposed at a temperature equal to or lower than the temperature of the high-temperature fluid, and can be inserted into the joint pipe fitting hole of the coupling member. The outer shape is formed to have a thickness corresponding to a set interval between the end face of the joint pipe and the opposing face of the coupling member, and is interposed between the joint pipe and the opposing face of the coupling so as to be interposed therebetween. A clearance setting member for a welded pipe joint, wherein the clearance is set to the thickness.