JPH0217274Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lining structure for a flange or the like in a pipe or a container.

[Prior art]

For pipes and containers that handle highly corrosive fluids, a lining layer made of a corrosion-resistant material such as titanium or tantalum is provided on the inner wall of a base material made of carbon steel or the like to improve corrosion resistance. ing.

Fig. 1 shows an example of the conventional structure of a flange part of a pipe etc. equipped with such a lining layer, in which a flange sheet 3 fixed to the flange surface of a flange 1 of a pipe etc. with silver solder 2, A nozzle sleeve 5 inserted into the wall 4 is abutted against each other and integrated by welding.

[The problem that the idea attempts to solve]

However, with such a lining structure such as a flange, the following problems occur due to the difference in melting point and coefficient of linear expansion between the lining layer made of the flange sheet 3 and nozzle sleeve 5 and the base material. That is, when welding both lining layers,
If the base metal is melted, there is a risk that the base metal may crack or carbon from the base metal may enter the welded portion 6 of the lining layer, resulting in a decrease in corrosion resistance.
For this reason, as shown in FIG. 1, it is necessary to separate the welded portion 6 from the flange surface, and the thickness of the flange sheet 3 tends to increase. Further, when the corrosive fluid is at a high temperature, a difference in thermal expansion occurs between the base material and the lining layer, and thermal stress is concentrated on the lining layer with a relatively small wall thickness, which tends to cause damage.

The present invention was developed in view of the above circumstances, and it is possible to weld the lining layer without melting the base material, thereby preventing cracks in the base material and deterioration of the corrosion resistance of the lining layer. The purpose is to provide a lining structure such as a pipe flange that can absorb the difference in thermal expansion and contraction between the material and the lining layer, prevent stress concentration on the lining layer, and also allow the lining layer to be made thinner. do.

[Structure of the idea]

In the lining structure of the present invention, a ring-shaped flange sheet is integrally provided on the flange surface of the pipe, etc. in a state that projects inward from the inner peripheral edge of the flange, and the lining structure is provided on the inner peripheral surface of the pipe, etc. near the flange sheet. , a ring-shaped back metal is provided along the circumferential direction, and on the inner peripheral surface of the back metal, the tip of the nozzle sleeve that covers the inner peripheral surface of the tube in a welded state and the inner peripheral edge of the flange sheet are welded. The present invention is characterized in that the nozzle sleeve is provided with a bendable knuckle portion with a gap formed between the end surface of the backing metal and the inner peripheral surface of the tube.

[Effect]

In the lining structure of the present invention, the flange sheet and nozzle sleeve are welded on the backing metal, so it is possible to reduce the heat effect on the base material such as the pipe due to welding, and the nozzle sleeve Since the knuckle part with a gap is formed between the pipe, etc. and the backing metal, even if there is a difference in thermal expansion and contraction between the nozzle sleeve and the pipe, etc., the knuckle part will remain in the range between them. It can be bent to absorb differences in thermal expansion and contraction.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIG. is pressed so that the inner peripheral edge protrudes inward from the tube wall 4 and is bent downward.
Further, a ring-shaped backing metal 8 made of the same metal as the lining layer is provided at the upper end of the tube wall 4, and on the backing metal 8, the inner peripheral edge of the flange sheet 7 and the upper edge of the nozzle sleeve 9 are connected. are butt welded, and the nozzle sleeve 9 is provided with a knuckle portion 10 at a step portion formed between the inner peripheral surface of the backing metal 8 and the tube wall 4 slightly below the upper edge. There is. The knuckle portion 10 is bent into an inclined state according to the step, and the outside of the bent portion is bent into a state in which a gap is left between the end face of the backing metal 8 and the inner circumferential surface of the tube wall 4. By being attached to the inner surface of the wall 4, it is constructed into a joint shape that can be bent and deformed as shown by the arrow C in FIG.

Since the flange part has such a lining structure, even if the backing metal 8 is melted during welding between the flange sheet 7 and the nozzle sleeve 9, the base metal will not be affected. This prevents cracking of the base material and infiltration of carbon into the welded portion 11.

Furthermore, when the base material and the lining layer try to expand thermally, as shown by arrows A and B in Figure 2, even if there is a difference in their thermal expansion, the force generated by thermal displacement will be applied to the knuckle. Since the deformation as shown by the arrow C in 10 can be absorbed, stress will not be applied to the lining layer and damage will occur, making it possible to reduce the thickness of the relatively expensive lining layer. .

[Effect of idea]

As explained above, the lining structure of a pipe flange or the like of the present invention provides the following effects.

Even if a difference in thermal expansion/contraction occurs between the base material such as a pipe and the lining layer, the knuckle portion can bend and absorb the difference in thermal expansion/contraction, thereby preventing thermal stress from acting on the lining layer. , damage to the lining layer can be prevented.

Since the flange sheet and the nozzle sleeve can be welded together without melting the base metal using the backing metal, cracking of the base metal can be prevented, and base metal components can be prevented from penetrating into the welded area, so that the lining layer can be welded. can prevent a decrease in corrosion resistance.

Since the knuckle portion is formed between the end face of the backing metal and the inner peripheral surface of the tube, the deformation of the knuckle portion when the internal pressure increases can be protected by the backing metal.

The above allows the lining layer to be made thinner.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of the main part showing an example of a conventional lining structure for a pipe flange, etc., and FIG. 2 is a vertical cross-sectional view of the main part showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Flange, 4...Pipe wall, 7...Flange sheet, 8...Backing metal, 9...Nozzle sleeve, 10...Knuckle part, 11...Welding part.

Claims (1)

[Scope of utility model registration request] A ring-shaped flange sheet is integrally provided on the flange surface of the pipe, etc. in a state that projects inward from the inner peripheral edge of the flange, and a ring is provided on the inner peripheral surface of the pipe, etc. near the flange sheet along the circumferential direction. A backing metal of the shape is provided, and a welded portion between the tip of the nozzle sleeve that closely covers the inner peripheral surface of the tube and the inner peripheral edge of the flange sheet is provided on the inner peripheral surface of the backing metal, and the nozzle sleeve A lining structure for a pipe flange, etc., characterized in that a bendable knuckle portion is formed with a gap between the end face of the backing metal and the inner peripheral surface of the pipe.