JP2002031248A - Seat forming method and seat structure for metal seat butterfly valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat forming method and seat structure for a metal seat butterfly valve, easily forming a seat at a valve casing or a valve element without taking time when casting and machining. SOLUTION: In forming a valve element seat 11 provided at the valve element 13 or a valve casing seat 12 provided at the valve casing 14, a sheet material is previously formed as a composite material having stainless steel surface layer parts 11a, 12a forming seat faces 11c, 12c, and ordinary steel base layer parts 11b, 12b welded to the valve element 13 or valve casing 14 which is a base material. The seat material formed of the composite material is inserted in the valve element 13 or valve casing 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet forming method and a seat structure for a metal seat butterfly valve, and more particularly to a technique for attaching a seat to a valve body.

[0002]

2. Description of the Related Art In a metal seat butterfly valve as shown in FIG. 3, for example, a valve element 2 is provided inside a valve box 1 so as to be rotatable around the axis of a valve rod 3, and a metal element is provided around the valve element 2. A valve body sheet 4 made of a material is provided, and a valve box sheet 5 that slides on the valve body sheet 4 is provided on the inner surface of the valve box 1.

[0003]

In a metal seat butterfly valve, a valve body sheet 4 and a valve box sheet 5 are provided.
Uses special stainless steel as its material to prevent mutual burning. The method of forming the valve body sheet 4 and the valve box sheet 5 includes a metal welding method of forming a metal on the valve body 2 or the valve box 1 and a sheet material at the time of casting the valve body 2 and the valve box 1. There is a way to

In the casting method, a special coating is applied to the sheet material in order to enhance the adhesiveness of the sheet material to the valve body 2 and the valve box 1, or a special stainless steel as shown in FIGS. Surplus a to be wrapped is provided in the valve body 2 and the valve box 1.

[0005] As described above, according to the cast-in method, man-hours for accelerating the welding of the sheet material at the time of casting, and the excess a
There is a problem that extra work such as man-hours for shaving the sheet material by shaving the sheet is involved.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and a sheet forming method of a metal sheet butterfly valve which can easily form a sheet into a valve box and a valve body without requiring any trouble during casting and processing. And a seat structure.

[0007]

According to a first aspect of the present invention, there is provided a sheet forming method for a metal sheet butterfly valve, comprising: a valve body sheet provided on a valve body or a valve box sheet provided on a valve box. When forming the sheet material, a sheet material is formed in advance as a composite material having a surface layer portion of special stainless steel forming the seat surface and a base layer portion of ordinary steel welded to a valve body or a valve box as a base material, and A sheet material made of a material is cast into a valve body or a valve box.

With the above construction, the sheet material which is a composite material when cast into a valve body or a valve box is a base material which is a base material without special coating or extra thickness since the base layer is made of ordinary steel. Alternatively, it can be easily and sufficiently welded to the valve box. For this reason, it is possible to reduce the man-hour required for coating at the time of casting and the man-hour required for removing excess thickness at the time of working as in the related art. In addition, since the sheet material integrally has a special stainless steel surface layer that forms the sheet surface on the base layer, the special stainless steel on the surface layer may be the minimum thickness necessary for processing the sheet surface. The amount of steel used is less than half that of conventional steel, and costs can be reduced.

According to a second aspect of the present invention, there is provided a metal sheet butterfly valve according to the present invention, wherein the sheet material forming the valve body sheet or the valve box sheet is a special stainless steel of a surface layer forming a seat surface and a base material. It is made of a composite material formed integrally with a body or a base layer of ordinary steel welded to a valve box.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A metal sheet butterfly valve according to an embodiment of the present invention will be described below with reference to the drawings. The basic structure of the metal seat butterfly valve is shown in Fig. 3 first.
Therefore, the description is omitted, and the main part will be described.

In FIG. 1 and FIG. 2, a sheet material forming a valve body sheet 11 or a valve box sheet 12 is made of a composite material in which metal materials of different materials are integrally formed in advance, and a surface layer portion 11a forming a seat surface is formed. , 12a are made of special stainless steel, and plain steel is used for base layers 11b, 12b to be welded to valve body 13 or valve box 14 as a base material.
This valve body sheet 11 or valve box sheet 12 is formed by:
When the valve body 13 or the valve box 14 is cast, the sheet material made of a composite material is stuffed, and then the surface layers 11a, 12
The surface a is processed to form the sheet surfaces 11c and 12c.

With the above-described structure, when the valve body sheet 11 or the valve box sheet 12 is cast into the valve body 13 or the valve box 14, the sheet material is previously formed into a composite material of special stainless steel and ordinary steel. It is possible to easily and sufficiently weld the base layer made of ordinary steel to the valve body 13 or the valve box 14 as a base material without applying a special coating or extra thickness as in the related art.

[0013]

As described above, according to the present invention, the sheet material forming the valve body sheet or the valve box sheet is formed into a composite material of special stainless steel and ordinary steel in advance, so that the conventional casting method can be used. Eliminating the coating process and the process of removing excess material during processing is unnecessary, reducing the man-hours required to form the valve body sheet or valve box sheet. It is only necessary to provide a special stainless steel having a thickness, and the amount of the special stainless steel used is reduced to less than half of the conventional one, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a valve seat structure of a metal seat butterfly valve according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part showing a valve box seat structure of the metal seat butterfly valve.

FIG. 3 is a schematic view showing a metal sheet butterfly valve.

FIG. 4 is a sectional view of a main part showing a valve seat structure of a conventional metal seat butterfly valve.

FIG. 5 is a sectional view of a main part showing a valve box seat structure of a conventional metal seat butterfly valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Valve sheet 12 Valve box sheet 11a, 12a Surface part 11b, 12b Base layer part 11c, 12c Seat surface 13 Valve body 14 Valve box

Claims (2)

[Claims] When a valve body sheet provided on a valve body or a valve box sheet provided on a valve box is formed, a sheet material is formed in advance by a surface layer portion of special stainless steel forming a seat surface and a valve body or valve serving as a base material. A sheet forming method for a metal sheet butterfly valve, comprising forming a composite material having a base layer portion of ordinary steel to be welded to a box and casting a sheet material made of the composite material into a valve body or a valve box. 2. A sheet material forming a valve body sheet or a valve box sheet is formed by integrating a special stainless steel of a surface layer forming a seat surface with a base layer of ordinary steel welded to a valve body or a valve box as a base material. A seat structure of a metal seat butterfly valve, characterized by being made of a composite material which is formed in a special manner.