JP3238130B2 - Butterfly valve seat ring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat ring for a wafer type butterfly valve, and more particularly to a seat ring including a reinforcing member for a center type wafer type butterfly valve.

[0002]

2. Description of the Related Art Conventionally, a fitting type seat ring made of an elastomer such as rubber has been frequently used as a seat ring of a central wafer type butterfly valve. Such a fitting type seat ring is sandwiched between piping flanges on both side surfaces of the valve body to prevent fluid leakage. Therefore, the seat ring is required to withstand the clamping of the pipe flange and not to be vibrated, raised or dropped due to the working fluid pressure or the like. A seat ring made of only an elastomer such as rubber may have insufficient rigidity. Therefore, a structure for reinforcing a seat ring made of an elastomer is disclosed in, for example, JP-A-52-98231.
No. 1993.

[0003] JP-A-52-98231 discloses that
A structure that reinforces with a phenolic resin reinforcing material and a structure that includes a cylindrical reinforcing member are disclosed as conventional structures.For such a conventional structure, those reinforced with a phenolic resin reinforcing material are: It teaches that a lot of machining and steps are required in the manufacturing process of the reinforcing material, and the reinforcing material is likely to be distorted at the time of molding the rubber member, so that post-processing is required, which causes an increase in cost. Further, in the case where the reinforcing member having the cylindrical shape is included, it is easy to manufacture the reinforcing member. However, when the reinforcing member is included in the rubber member by injection molding, it is difficult to prevent the displacement and distortion of the reinforcing member. In addition, it is taught that since the rubber member is divided into the inner peripheral surface and the outer peripheral surface by the reinforcing member, problems occur in the rigidity and adhesion of the rubber member, and it becomes difficult to exhibit the expected performance. I have. Therefore, Japanese Patent Laid-Open No. 52-98
No. 231 invention forms a tongue-shaped piece extending outward at the upper end of a cylindrical reinforcing member at a flange-like interval,
A structure has been proposed in which the tip of the tongue piece is exposed on the outer peripheral surface of the seat ring.

However, in the structure proposed in Japanese Patent Application Laid-Open No. 52-98231, when the reinforcing member is sandwiched between the flanges because of its thin thickness, there is a danger of leakage due to low adhesion strength with the flange, and the fluid used If the fluid is a corrosive fluid, the fluid leaking from the valve shaft may corrode the reinforcing member.
In addition, when sandwiched between flanges, as a design problem,
The inner diameter of the flange is slightly larger than the outer diameter of the pipe, and the inner diameter of the flange substantially matches the reinforcing member size of the seat ring to increase the adhesion strength of the flange. There is a problem that can not be done.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a reinforcing member in which bent portions are formed at both ends of a plate-like portion made of a corrosion-resistant rigid material in a flange shape so as not to be exposed from the entire surface of the seat ring. It is an object of the present invention to solve the problem seen in the conventional seat ring reinforcing structure by including it.

[0006]

Means taken by the present invention to solve the above problem is to insert a seat ring made of an elastomer having a reinforcing material disposed inside a valve body of a butterfly valve , The reinforcing material is a butterfly valve formed by forming a plate of a rigid material having corrosion resistance into a ring shape ,
Bends are formed at both ends of the reinforcement that extend in both directions.
It is characterized by having.

[0007] A corrosion resistant case for packing
The case is fixed to a reinforcing material.
While inserting it into the valve stem insertion portion of the seat ring and attaching the valve stem to the case.
That a cylindrical portion that extends along
Features.

An opening penetrating the reinforcing member is formed, and the reinforcing member is
Is included so as not to be exposed from the surface of the seat ring,
The elastomers located on the inner and outer surfaces of the reinforcement are linked through the openings.
It is characterized by the conclusion.

[0009] A reduction gradient is applied to the inside diameter of both ends of the seat ring.
Form and match the inside diameter of pipe flange or outside pipe diameter
It is characterized by doing so.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below. In the figure, (1) is a valve body of a wafer type center type butterfly valve according to the present invention, and a sealing (4) including a reinforcing material (5) is mounted on an inner peripheral surface thereof. A disc-shaped valve element (2) pivotally supported by a valve rod (3) is rotatably disposed on the inner peripheral surface of the seat ring (4). The flow path passing through the butterfly valve is opened and closed by the contact and separation with the inner peripheral surface of (4). Valve stem (3)
Is divided into a drive side valve stem (3a) extending outside the valve body and connected to a desired actuator, and a floating valve stem (3b). The drive side valve stem (3a) It is fixed to 2). The floating valve stem (3b) is fixedly fastened to the bottom cover (6) with hexagon bolts via packing. However,
The valve stem (3) is not limited to a two-piece valve stem, and it goes without saying that a valve stem having one drive side and one idle side may be used.

In a free state before being disposed on the piping flange, the seat ring (4) is in a state of projecting from both ends of the valve body (1) by α, and as shown in FIG.
When it is clamped in (7), the protruding portion α is tightened and plays a role of a gasket. The butterfly valve is sandwiched between the left and right pipe flanges (7) and is tightened by long bolts. The inner diameter of the pipe flange (7) is formed slightly larger than the outer diameter of the pipe (8), and after the pipe (8) is inserted into the flange (7) as shown in FIG.
It is fixed by welding. The outer diameter of the pipe (8) is JI
The dimensions are specified for each size according to the S standard. The present invention is characterized in that a reduction gradient (9) is provided at both inner diameters of the seat ring (4) based on these dimensions. The reduction gradient (9) is formed from the inner diameter of both ends of the seat ring (4) to both ends, whereby the inner diameter of the pipe flange or the outer diameter of the pipe can be matched. It is possible to prevent the elastic body of the seat ring from being deformed in the inner diameter direction when sandwiched, to eliminate unnecessary elastomer, and to prevent an increase in fluid resistance.

The portion outside the contraction gradient (9) is the portion which comes into contact with the pipe flange surface and is compressed. The magnitude of the compressive strength of this portion determines whether or not the fluid leaks to the outside. You.
That is, since the pipe flange (7) is made of a rigid material and the seat ring (4) is made of an elastomer having elasticity, the shape of the reinforcing material (5) inside the seat ring (4) to be brought into contact with the seat ring (4) or the seat ring is not changed. The shape of the contact portion, particularly the thickness of the elastomer, can prevent leakage of fluid from the portion. The present invention provides a seat ring (4) for abutting a pipe flange (7).
To optimize the compression strength of the seat ring
The second feature is that a reinforcing material which has an effective shape inside (4) and which can make the thickness of the elastomer of the contact portion suitable is included. The reinforcing material (5) has a structure in which a plate made of a rigid material, for example, carbon steel, stainless steel, or the like is formed in a ring shape, and has a thickness of about 30% of the total thickness of the seat ring (4). . The reinforcing material (5) is formed to have a diameter such that it is positioned slightly outward in the seat ring (4), and is included in the seat ring (4) when the elastomer is injected.

As shown in FIGS. 2 to 4, a plurality of rows of openings (10) penetrating vertically are formed in the plate-like portion (5a) of the reinforcing member (5), and an elastomer passing through the openings (10) is formed. Connect the elastomers located inside and outside the plate-like portion (5a) in an anchor-like manner, and the peeling of the elastomer is effectively prevented. The inner and outer edges of the opening (10) are chamfered in order to reduce the resistance during the injection of the elastomer. The shape of the opening (10) is preferably circular or square, but is not limited thereto. The number, position, shape, gap, etc. of the openings (10) are
Depending on the valve diameter and the manufacturing method at the time of elastomer injection,
It is appropriately selected. A flange-shaped bent portion (5b) is integrally formed at both ends of the plate-shaped portion (5a) of the reinforcing material (5). The flange-shaped bent portion (5b) may be provided in any of the inner diameter direction and the outer diameter direction, or may be provided in both directions. An uneven portion (11) having a mountain-shaped cross section (FIG. 5) or an uneven portion (11) having a square cross section (FIG. 6) is formed on at least one of the inner and outer surfaces of the plate-shaped portion (5a). It is preferable to further strengthen the integration of. It is desirable that each corner of the reinforcing material (5) be cut off by chamfering or the like in order to reduce resistance when the elastomer is injected.

An O-ring (12) housed in an O-ring case (13) is inserted together with a lubricant into the valve stem insertion portion of the seat ring (4) to achieve a secondary sealing function. The O-ring case (13) is composed of a plurality of members combined and integrated with each other, and is fixed to the reinforcing member (5). Each member of the O-ring case (13) extends along the valve stem, has a cylindrical portion (14) for guiding the rotation of the valve stem, and serves to guide the rotation of the valve stem (3). And smooth rotation. The cylindrical portion (14) serving as a valve stem guide prevents deformation of the valve stem insertion portion even when the valve body (2) is pressed by fluid pressure when the valve is closed, and also prevents fluid from flowing through the valve stem insertion portion. Leakage is prevented. O-ring case (13) and cylindrical part serving as valve stem guide
(14) is preferably formed of a stainless steel or bronze-based material from the viewpoints of spreadability, corrosion resistance, and workability.

[0015]

According to the present invention, since both ends of the reinforcing member included in the seat ring are bent in a flange shape in the inner and outer radial directions, the contact with the pipe flange surface at the time of disposition is ensured and also. It becomes strong and can prevent deformation in the seat ring inner diameter direction. Since an O-ring case having a cylindrical portion serving as a valve stem guide is inserted into the valve stem insertion portion of the seat ring, the valve stem can be smoothly rotated, and the deformation of the valve stem insertion portion can be prevented. Leakage can be prevented. Reinforcement
An opening is formed through the reinforcing member and the reinforcing member is
Enclose it so that it is not exposed from the surface and place it on the inner and outer surfaces of the reinforcement.
Since the elastomer to be placed is connected via the opening,
The elastomers located on the inner and outer surfaces of the
Increased adhesion between strong materials and elastomers, resulting in severe fluid
It can correspond to the matter. A reduction gradient is formed at the inner diameter of both ends of the seat ring so as to match the inner diameter of the pipe flange or the outer diameter of the pipe, thereby preventing the elastic portion of the seat ring from being deformed in the inner diameter direction during installation. I can do it.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a butterfly valve according to the present invention.

FIG. 2 is an enlarged sectional view of FIG. 1A part;

FIG. 3 is a sectional view taken along the line B-B 'of FIG. 1;

FIG. 4 is an enlarged perspective view showing a part of a reinforcing member.

FIG. 5 is a cross-sectional view showing one modification of a reinforcing member.

FIG. 6 is a sectional view showing another modification of the reinforcing member.

[Explanation of symbols]

 (1) Valve body (2) Valve body (3) Valve stem (4) Seat ring (5) Reinforcement material (5a) Plate portion (5b) Bend portion (6) Bottom cover (7) Piping flange (8) Piping pipe (9) Reduction gradient (10) Opening (11) Unevenness (12) O-ring (13) O-ring case (14) Cylindrical

Claims (4)

(57) [Claims] 1. A seat ring made of an elastomer having a reinforcing member disposed therein is inserted into a valve body of a butterfly valve ,
The reinforcing member is a butterfly valve formed by forming a plate of a rigid material having corrosion resistance into a ring shape.
A seat ring for a butterfly valve, wherein a bent portion extending in both the inner and outer diameter directions is formed . 2. A corrosion resistant case for storing packing is provided.
The case is fixed to a reinforcing material.
While inserting it into the valve stem insertion portion of the seat ring and attaching the valve stem to the case.
That a cylindrical portion that extends along
The seat ring according to claim 1, wherein: 3. An opening penetrating through the reinforcing member, wherein the reinforcing member has
Is included so as not to be exposed from the surface of the seat ring,
The elastomers located on the inner and outer surfaces of the reinforcement are linked through the openings.
The seat according to claim 1 or 2, wherein
Ning. 4. A reduction gradient is applied to the inner diameter of both ends of the seat ring.
Form and match the inside diameter of pipe flange or outside pipe diameter
4. The method according to claim 1, wherein
The seat ring according to the item.