JPH0259342B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a central butterfly valve with a heat resistant lining.

Conventionally, there has been no known central butterfly valve that has the heat resistance to withstand high temperatures of around 500 degrees Celsius or higher and has zero fluid leakage. In the conventionally known central butterfly valve, as shown in FIG. 1, the inner peripheral surface of a valve body 1 is lined with a Teflon sheet 2, and a valve plate 3 abuts to compensate for the elasticity of the Teflon lining 2. A rubber plate 4 is inserted inside the Teflon lining 2 corresponding to the valve seat portion.

However, such central butterfly valves with Teflon lining have low heat resistance because the lining is made of Teflon and a rubber plate is used as an elastic body inside.
It could not be used at all for high-temperature fluids at temperatures above ℃.

Therefore, it is conceivable to change the lining from Teflon to a metal sheet in a central butterfly valve with such a structure, but the rubber plate has a weak repulsive force and when the valve plate comes into contact with it, the metal sheet deforms. It was impossible to obtain sufficient sealing performance because there was no force to push back. Furthermore, the seal structure of the valve stem is designed to use a Teflon lining, and simply changing the lining material from Teflon to a metal sheet will not prevent fluid from leaking around the valve stem. Nakatsuta.

This invention aims to solve the above-mentioned drawbacks and problems found in the conventional central type butterfly valve using Teflon lining, and the technical problem is to solve the problem of the valve body of the central type butterfly valve. The liquid contact part of the inner wall is covered with a lining material made of a thin metal plate with good heat resistance and contact resistance, and sufficient elastic restoring force is applied to the lining material over the entire contact surface between the lining material and the valve plate. The purpose is to apply the sealant and form a seal.

The technical means of the present invention for solving the above technical problems is to cover the part of the valve body that comes into contact with the fluid inside the valve with a lining material made of a thin metal sheet that is resistant to contact and heat. The valve seat surface of the lining material is brought into contact with a valve plate whose surface is a part of a spherical surface, and a convex portion protruding in the inner radial direction is formed continuously along the inner peripheral surface on the valve seat surface of the lining material, and the convex portion has heat resistance. A coil spring is inserted and arranged to impart elasticity to the convex portion, and the top of the convex portion is located on a spherical surface having the same center as the spherical surface forming the outer peripheral surface of the valve plate, and the diameter of the spherical surface is set to the above-mentioned diameter. The valve plate is formed to a value obtained by subtracting the bulge allowance from the diameter of the spherical surface that forms the outer circumferential surface of the valve plate, and the convex portion is formed to go around the valve stem hole all the way around the valve stem hole. The purpose is to provide sufficient sealing performance by biting into contact with the same protrusion allowance at all points, and also to seal leakage in the direction of the valve shaft with a convex part that goes around the valve shaft hole. .

The technical means of this invention works as follows. That is, when the valve plate is pushed into the valve body in order to assemble the valve plate, the convex part of the lining material lining the inner surface of the valve body is depressed, and the convex part becomes lower as shown by the dashed line in FIG. The material tends to flow sideways toward the valve flange surface. However, since there is an elastic body inside the convex part that has at least enough repulsive force to push back the deformation of the lining material and restore it, the reaction force of the elastic body is applied to the lining material, and the lining material is pushed against the valve plate. exerts a reaction force. Therefore, the outer circumferential portion of the valve plate and the top of the convex portion of the lining material are pressed together to a sufficient extent to act as a seal.

On the other hand, the entire top of the convex portion is on a spherical surface having the same center as the spherical surface forming the outer periphery of the valve plate, and the diameter of the spherical surface is smaller by the amount of the bulge, so when the two are combined, The top of the convex portion and the outer periphery of the valve plate touch at all points with the same protrusion width,
As mentioned above, the valve plate and the lining material are sealed over the entire circumference as a result of pressing each other with sufficient force to act as a seal.

Effects specific to this invention are as follows.

That is, as a means to solve the above-mentioned technical problem, it is possible to fix a lining material 5 on the outer peripheral surface of the valve plate 3 and provide a convex portion 6 as shown in FIG. In this case, the sealing effect between the valve body and the valve plate is similarly obtained, but the reliability of the seal between the lining material and the valve plate becomes a problem. In the structure shown in Fig. 3, the lining material 5 is caulked to the valve plate 3 to obtain a seal between the two, but the surface of the valve plate 3 that is orthogonal to the streamline is not flat, and the valve stem is Lining material 5
There is a drawback that caulking is not easy. Therefore,
Instead of caulking, it is possible to insert some kind of heat-resistant gasket between the lining material and the valve plate, but this method has the disadvantage that the outer circumference of the valve plate becomes thicker, resulting in greater pressure loss as a valve, and it also becomes expensive and complicated. There are also drawbacks.

Compared to the one shown in Fig. 3 which has such drawbacks, the present invention does not have such drawbacks and solves the above-mentioned technical problem, and also provides a central type for high temperature use that could not be obtained with the prior art. A butterfly valve is obtained.

Embodiments of the present invention will be described below with reference to the drawings. Referring to FIGS. 4 to 11, reference numeral 10 denotes a valve plate whose center is fixed to a valve shaft 11, and whose outer peripheral surface 12 is formed as a part of a spherical surface. A lining material 13 is fixed to and covers the inner peripheral surface of the valve body 14, and is made of a thin metal plate having heat resistance and contact resistance, such as a stainless steel plate. The lining material 13 is made of an annular member having a cross-sectional shape as shown in FIGS. 6 to 8. In order to incorporate the lining material 13, the valve body 14 is divided into two upper and lower parts 14a and 14b as shown in FIG. and are fastened with bolts 15.

To assemble the valve plate 10, first bend the lining material 13 into a slightly elliptical shape in the direction of the valve axis, insert the valve plate 10 into the lining material 13 in an open state, and then insert the divided valve body 14 into the lining material. It is placed over the outer periphery of the material 13 and fastened with bolts 15.

As shown in FIGS. 6 to 8, the lining material 13 has a protrusion 16 that protrudes in the inner diameter direction and is continuously formed around the inner peripheral surface, and around the valve stem hole 17. The valve shaft hole 17 is formed in a circular shape concentric with
surrounding. The tops of the convex portions 16 are all located on a spherical surface having the same center as the spherical surface forming the outer peripheral surface of the valve plate 10, and the diameter thereof is formed to be smaller by the amount of the bulge. Therefore, when the two are combined, the top of the convex portion 16 comes into contact with the outer circumferential surface 12 of the valve plate 10 with the same protrusion width at all points, and a reliable seal is established between the two. As a method for forming the convex portion 16 on the lining material 13, in addition to forming the convex portion in advance by an appropriate means such as a rubber press, the lining material is formed flat and when assembled to the valve body 14, the convex portion 16 is formed in advance. , valve body 1
The convex portion 16 may be naturally formed by elastically and plastically deforming the lining material 13 in response to the protrusion of the elastic body 18 inserted into the groove 4. The latter method has the advantage that the lining material can be manufactured at low cost.

An elastic body 18 is inserted into the groove on the back surface of the convex portion 16 . The elastic body 18 has at least sufficient repulsive force to push back the deformation of the lining material 13 and restore its original shape, has the same heat resistance as the lining material, and is made of, for example, a coil spring.

When forming the elastic body 18 with a coil spring, as shown in FIG. 9, both ends of the two coil springs 18 are bent into a semicircular shape, and both are welded or mechanically fixed at point A to form a circular shape. , the circular portion is a circular convex portion 1 formed around the valve stem hole 17.
At the same time, the linear part is inserted into the convex part extending linearly on the inner circumferential surface of the lining material.

The elastic body 18 inserted into the convex portion 16 applies a sufficient reaction force to the convex portion 16 when the convex portion 16 contacts the outer peripheral surface of the valve plate 10 and is crushed.

In order to prevent the seal around the valve shaft hole 17 from being damaged and the pressure inside the valve to reach the valve body, the valve shaft hole portion of the lining material 13 is extended in the direction of the valve shaft to form a shaft seal portion 19. do. Reference numeral 21 denotes a bush that is fitted into a small-diameter neck portion 20 formed between the shaft seal portion 19 and the valve shaft hole portion, and is formed in a two-part structure as shown in FIG. ing.

A groove is also formed in the part of the valve body 14 that corresponds to the convex part 16, and a part of the coil spring 18 is inserted therein to prevent the coil spring from moving laterally, and the unevenness of the outer peripheral surface of the coil spring is formed on the lining surface. In order to prevent the coil spring from sticking out, it is preferable to cover the coil spring with a suitable soft material and then insert it into the convex portion 16.

The lining material 13 is formed into a shape having a flat surface with a cross section without forming the convex portion 16 in the center as described above, and the elastic body 18 is formed on the valve body 14 almost entirely except for a part. The lining material 13 could be applied to the valve body 14 by forming a groove to receive the lining material 13. In this case, the lining material 13 naturally protrudes slightly due to the elasticity of the elastic body 18, so that good contact with the valve plate 10 is achieved, and the convex portion surrounding the valve stem hole 17 is There is an advantage that there is no need for a complicated structure like 16.

FIG. 12 shows another embodiment of the present invention, in which the shaft seal portion 18 also has a convex portion 2.
2, and the top of the convex portion 22 is brought into contact with the outer peripheral surface of the valve shaft 11 to seal between the lining material 13 and the valve shaft 11. It goes without saying that the elastic body 18 may be inserted into the convex portion 22 in order to generate the reaction force of the convex portion. This has the advantage of eliminating the need for a gasket around the valve shaft.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional perspective view of a known central butterfly valve, FIG. 2 is a sectional view for explaining the deformed state of the metal sheet, and FIG. 3 is for explaining the effects of the present invention. FIG. 4 is a longitudinal cross-sectional view of the butterfly valve according to the present invention, and FIG. 5 is a cross-sectional view taken along line V-V in FIG. 4. , FIG. 6 is a longitudinal sectional view of the lining material, FIG. 7 is a plan view of a part of the lining material, FIG. 8 is a sectional view taken along the line of FIG. 7, and FIG. 9 is a coil spring. Fig. 10 is a plan view of the circular connecting portion of the valve body, Fig. 11 is a longitudinal sectional view of the valve body.
The figure is a perspective view of the bush, and FIG. 12 is a longitudinal sectional view of the main parts showing another embodiment of the invention. 10... Valve plate, 11... Valve stem, 12... Outer circumferential surface of valve plate, 13... Lining material, 14... Valve body, 15... Bolt, 16... Convex portion, 17... Valve stem hole , 18...Elastic body, 19...Shaft seal portion, 20...Neck portion, 21...Button, 22...
Convex part.

Claims (1)

[Claims] 1. The part of the valve body that comes into contact with the fluid inside the valve is covered with a lining material made of a thin metal sheet that is resistant to contact and heat, and is brought into contact with a valve plate whose outer peripheral surface is part of a spherical surface, and the lining is A convex portion protruding in the inner radial direction is continuously formed on the valve seat surface of the material along the inner peripheral surface, and a heat-resistant coil spring is inserted into the convex portion to impart elasticity to the convex portion, The top of the convex portion is located on a spherical surface having the same center as the spherical surface forming the outer peripheral surface of the valve plate, and the diameter of the spherical surface is obtained by subtracting the bulge allowance from the diameter of the spherical surface forming the outer peripheral surface of the valve plate. 2. A central type butterfly valve, characterized in that the convex portion is formed around the valve stem hole, and the convex portion is formed around the valve stem hole.