JPS645194B2 - - Google Patents

Description

Detailed Description of the Invention A. Purpose of the Invention [Industrial Field of Application] The present invention relates to so-called rubber-lined steel pipes in which the inner surface of the steel pipe is coated with synthetic rubber, and more specifically, to rubber-lined steel pipes that are interconnected. Regarding the improvement of the joint structure.

[Prior Art] Rubber-lined steel pipes are generally used as pipes for transporting slurry containing solids in the fluid due to the abrasion resistance of rubber, and the corrosion resistance of steel pipes due to the rubber coating. It has a wide range of uses as it is effective even when the slurry contains components that easily corrode steel materials.

However, in the past, no special consideration was given to the joints of rubber-lined steel pipes, and general flange joints were used.As a result, as shown in Figure 1, the lining layer A was interrupted at the joint, resulting in sealing. Gasket B is used separately for
This results in a structure such as a step C being formed at the seam. As a result, the solid matter in the slurry collides with the corner where the lining layer breaks, causing damage to the spot, causing the lining layer to peel off from the spot, and corrosion of the steel material to begin.
In addition, the sealing effect of the gasket is insufficient (corrosion of the flange surface promotes leakage at the contact surface),
Fluid leaks from joints often occur.

Furthermore, in recent years, there has been a trend to transport slurry under high pressure, and under this high pressure, fluid leakage from the joint becomes even more noticeable.

[Problems to be Solved by the Invention] In view of the above circumstances, the present invention aims to provide a new rubber-lined steel pipe joint that eliminates the various drawbacks of conventional rubber-lined steel pipes and can also be used for high pressure applications. purpose.

B. Structure of the invention [Means for solving the problems] In order to achieve the above object, the joint structure for rubber-lined steel pipes of the present invention adopts the following structure (technical means). That is, in a rubber-lined steel pipe having a rubber lining layer on the inner surface and metal flanges at the ends that abut each other and are joined by a tightening tool, the mutually opposing end surfaces of the metal flanges have annular flanges that extend to the inner surface of the tube. A recess and an abutting surface that connects to the flange accommodating recess and abut each other are respectively formed, and the rubber lining layer is extended to the flange accommodating recess of the metal flange, and its surface becomes substantially flush with the abutting surface and comes into close contact with each other. A brim-like rubber lining layer is formed, and an O-ring groove is provided in the circumferential direction on one side of the brim-like rubber lining layer, and an O-ring groove is provided in the O-ring groove.
It is characterized by being fitted with a ring.

In the above configuration, the surface of the brim-like rubber lining layer is substantially flush with the abutting surface, which means at least to the extent that it does not recede further than the abutting surface and does not cause the abutting surfaces to come into contact with each other. It means not to stand out.

[Function] Each component of the joint structure of the present invention exhibits the following actions and functions. That is, although the flanged rubber lining layers are brought into close contact with each other by tightening with the flange tightening tool, they are not compressed excessively by the abutting surfaces, and therefore, a bulge occurs at the joint between the flanged rubber lining layers (see Fig. 3). (dotted line) does not occur, and the O-ring is effectively retained. Also,
Since the brim-shaped rubber lining layer is restrained and accommodated in the brim-accommodating recess, deformation due to high pressure of the fluid in the pipe is prevented, and the contact surface of the brim-shaped rubber lining layer is protected against high-pressure fluid by the action of an O-ring. Demonstrates a great sealing effect against Furthermore, since the abutment surface is made of metal contact, it can withstand the strong clamping force of the clamping tool and also exhibits a sealing effect on this surface.

[Example] Hereinafter, an example of a joint structure for a rubber-lined steel pipe of the present invention will be described based on the drawings.

FIGS. 2 and 3 show one embodiment thereof.

In the figure, 1 is one steel pipe to be joined, and 2 is the other steel pipe.

Lining layers 3 and 4 are coated on the inner surfaces of the steel pipes 1 and 2, and are preferably made of urethane rubber from the viewpoint of wear resistance and corrosion resistance, but other synthetic rubbers may also be used.

Reference numerals 5 and 6 are flanges formed at the ends of the steel pipes 1 and 2, and 5A and 6A are end surfaces of the flanges 5 and 6 facing each other. The end surfaces 5A and 6A have annular collar housing recesses 51 and 61, abutment surfaces 52 and 62, and a fitting portion 5, respectively, from the inside of the tube toward the outside.
It is composed of three parts: 3 and 63. That is, the brim-accommodating recesses 51 and 61 accommodate the brim-like lining layer, restrain its deformation in the outer diameter direction, and prevent the abutment surface 5 from forming.
When both flanges 56 are tightened by the tightening tool 7, the abutting surfaces 52, 62 come into close contact with each other to bear the tightening force, and the fitting portions 53, 63
The flanges 5 and 6 are formed in a nested shape (socket shape), and when these portions fit together, the flanges 5 and 6 are centripetally connected to each other, and are connected without creating a step on the inner surface. The end faces 5A and 6A that exhibit the function are not included in this embodiment, and the fitting part 5
3 and 63 are brought into close contact with each other, and the abutting surfaces 52 and 62 are brought into close contact with each other.
It is also possible to adopt a mode in which the fitting portions 53 and 63 are not formed and only the collar accommodating portion and the abutting surface are provided.

5B and 6B are bolt through holes drilled at appropriate locations in the circumferential direction of the flanges 5 and 6. Bolts 71 of the fastener 7 are inserted into the bolt through holes 5B and 6B, and nuts 72 are used to tighten both flanges 5. , 6 are clamped and tightened. 5' and 6' are flanges 5 and 6, respectively.
The end of the reduced diameter part and the end of the steel pipe 12 are integrally fixed by welding. In addition,
It is possible to omit the reduced diameter portions 5' and 6'.

The lining layers 3, 4 are extended and coated on the inner peripheral surfaces of the flanges 5, 6, and are further bent and extended on the end surfaces 5A, 5B of the flanges 5, 6,
Flange-shaped rubber lining layers 3A and 4A are formed.
The brim-like rubber lining layers 3A, 4A are restrained and accommodated in the brim-accommodating recesses 51, 61 of the flanges.

Reference numeral 8 denotes an annular O-ring groove formed on one side (3A in this example) of the brim-like rubber lining layers that are welded together, and an O-ring 9 is fitted into the O-ring groove 8. .

C. Effects of the Invention Since the present invention has the configuration and functions described above, it has the following unique effects.

Since the joint portion is formed as a continuous smooth surface by the rubber lining layer, there is no difference in level, and therefore, there is no damage (peeling) from this portion.

Since the connecting surface is doubly sealed by the contact surface of the brim-like rubber lining layer and the O-ring, it can withstand high pressure and is effective as a joint for high-pressure pipes.

[Brief explanation of the drawing]

FIG. 1 is a partial longitudinal sectional view of a joint portion of a conventional rubber-lined steel pipe. FIG. 2 is a longitudinal sectional view showing an embodiment of the joint portion of the rubber-lined steel pipe of the present invention, and FIG. 3 is an enlarged view of the main part thereof. 1, 2... Steel pipe, 3, 4... Rubber lining layer, 3A, 4A... Flange-shaped rubber lining layer, 5,
6...Flange, 5A, 6A...End face, 51, 6
1...Flame housing recess, 52, 62...Abutment surface, 7...
...Tightening tool, 8...O-ring groove, 9...O-ring.

Claims (1)

[Scope of Claims] 1. A rubber-lined steel pipe 1 having rubber lining layers 3 and 4 on the inner surface and metal flanges 5 and 6 at the ends that abut each other and are joined by a fastener 7,
2, the mutually opposing end surfaces 5A, 6A of the metal flanges 5, 6 are provided with annular flange accommodating recesses 51, 61 connected to the inner surface of the tube and abutment surfaces 52, 62 that are continuous with the flange accommodating recesses 51, 61 and abut against each other. are formed, respectively, and the rubber lining layers 3 and 4 are extended to the collar receiving recesses 51 and 61 of the metal flanges 5 and 6, and their surfaces are substantially flush with the abutment surfaces 52 and 62 and are in close contact with each other. Flange-shaped rubber lining layers 3A, 4A are formed, and an O-ring groove 8 is provided in the circumferential direction in one of the flanges-shaped rubber lining layers 3A, 4A.
A joint structure for rubber-lined steel pipes, characterized in that an O-ring 9 is fitted into the joint structure. 2. Claim 1 in which centripetal fitting portions 53, 63 are formed on the end surfaces 5A, 6A of the flanges 5, 6.
Joint structure of rubber-lined steel pipes as described in . 3. The rubber-lined steel pipe joint structure according to claim 1 or 2, wherein the rubber lining layers 3, 4, 3A, and 4A are urethane rubber.