JPS6119246Y2 - - Google Patents

Description

[Detailed explanation of the invention] (1) Purpose of the invention (industrial field of application) This invention relates to a chimney valve that is especially suitable for processing flammable fluids.

(Prior art and issues to be solved) In a chi-shaped valve, a seat ring made of an elastic material such as rubber is arranged between the annular valve body and the outer periphery of the valve plate to perform a sealing action when the valve is closed. Valves made in the above-mentioned manner are well known in the art. This type of valve has an excellent sealing effect because it uses an elastic seat ring made of rubber, but the seat ring itself has poor heat resistance and corrosion resistance, so it is not suitable for use in pipes that handle flammable fluids. I couldn't deal with the unexpected situation.

In order to avoid such drawbacks, so-called metal touch valves have been proposed in the past, in which the valve seat part on the inner circumferential surface of the valve body and the outer circumferential surface of the valve plate directly contact each other to perform a sealing action. Because metal surfaces come into direct contact with metal surfaces, it is difficult to process them to prevent leakage, and it has been difficult to achieve a practical sealing effect due to cost considerations.

In view of these current circumstances, a seat ring made of an elastic material such as rubber is used under normal conditions, and when it is damaged by a fire, a temporary sealing action is performed using the metal touch method (in this case, the metal touch part is cost-effective). (The accuracy shall be set to an allowable level in terms of surface area) has already been proposed, for example, as seen in Japanese Patent Publication No. 32861/1983.

However, in this type of valve, the valve action by the elastic seat ring and the valve action by the metal touch coexist independently, and when the sealing action by the seat ring is lost, the metal touch Normally, the valve is constructed so that the sealing mechanism part of the valve acts, which is not preferable because the valve becomes larger in the direction of fluid flow and the mechanism becomes complicated.

The present invention was developed in order to deal with such a situation, and the sealing function of the seat ring and the sealing function of the metal touch part are placed close to each other and perform the sealing function together at all times. An object of the present invention is to provide a straw-shaped valve that does not cause time loss in switching from a sealing operation to an emergency sealing operation.

(2) Structure of the invention (technical means for solving the problem and its effects) In order to achieve the above purpose, the invention includes:
The elastic seat ring is made of knitted fibers made of polytetrafluoroethylene (hereinafter referred to as Teflon (trade name)), and the seat ring and the metal touch portion are arranged adjacent to each other.

With this structure, even if there is some leakage at the metal touch part, the Teflon seat ring will always provide a good sealing effect, and even if the Teflon seat ring burns out, it will remain intact temporarily. A sealing effect is achieved by metal touch, and since Teflon is used, the opening/closing torque of the valve is extremely small.

(Explanation of Embodiment) FIG. 1 is a partial side sectional view showing the main parts of the chimney-shaped valve according to the present invention. The valve body 1 is formed by welding the inner metal 11 provided with the truncated conical inner circumferential surface 12 for sealing, and a valve body 1 is arranged inside the valve body 1 so as to be rotatable within the valve body by a valve stem (not shown). A valve plate 2 is provided. An annular recess 24 is formed on the outer periphery 1 side of the valve plate 2, and an annular holding fitting 21 is arranged in this part. It is fixed to the valve plate 2 by means of fixing means (the position of one of which is indicated by reference numeral 4 in the figure). Approximately triangular recesses 22, 2 are provided at opposing positions on one side of the recess on the valve plate side and on the inner surface of the holding fitting.
3 is formed, and a seat ring 3 made of Teflon and having a substantially rectangular radial cross section is placed inside an annular storage portion formed by these recesses 22 and 23 and opening to the outer circumferential surface of the valve plate, a part of which is shaped like the above-mentioned one. It is installed internally so as to protrude from the opening of the annular storage section.

As mentioned above, the seat ring 3 is formed by knitting a large number of bundles 31 of Teflon fine fibers and forming them into a generally rectangular cross section so as to approximately match the recesses 22 and 23 shown in FIG. It is. In some cases, this material is further filled with Teflon fine particles dispersed therein to appropriately fill the space formed inside. The sheet ring formed in this way is different from the case in which Teflon is normally used in the form of a plate or block, and because it is an aggregate of fine Teflon fibers, it exhibits great elasticity as a whole.

Such a seat ring 3 is inserted into the valve plate peripheral groove formed by the recesses 22 and 23 shown in the first figure,
At this time, a part of the seat ring is made to slightly protrude outward in the radial direction of the valve plate, and when the valve plate is in the closed position shown in FIG.
It shall be placed so that it is in pressure contact with 2. Furthermore, as shown in the same figure, the relative position of the valve plate and the valve body is determined so that the seat ring 3 comes into pressure contact with the sealing surface 12 at a position close to the metal touch portion M where the valve plate and the valve body directly contact each other.

With this structure, Teflon, which originally has low elasticity and high rigidity, is made into a bundle of fibers, and if necessary, by mixing Teflon fine particles, the elasticity of the bundle as a whole can be freely adjusted. It is possible to obtain the optimum sealing action depending on the fluid pressure.

Furthermore, although Teflon has high rigidity, it also has an extremely low coefficient of friction, so by configuring the seat ring as described above, it is possible to achieve an excellent sealing effect due to its high elasticity and to reduce the torque required to open and close the valve.

In addition, since the part that performs the sealing action by Metal Touch is always acting at the same time as the Teflon seat ring part, even if the Teflon burns out due to an accident, there is no time delay and the Metal Touch can only provide a temporary sealing action. However, the burnt out Teflon does not completely disappear from that position, so it acts to promote the metal seal, thereby improving the sealing effect of the metal touch.

Further, since the Teflon sealing material formed in a bundle can be deformed to a large extent, it is not necessary to process the shape of the recess formed at the periphery of the valve plate into a precise cross-sectional shape, which is advantageous from a cost standpoint.

(3) Effects of the invention As explained above, the present invention not only makes effective use of Teflon, which has high rigidity and corrosion resistance, and has low elasticity, to obtain an effective sealing effect, but also seals tightly with the metal touch seal. Because of this, it has a simple structure and is advantageous in terms of cost, and it also has the effect of promoting metal sealing in the event of an accident.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a chimney-shaped valve according to the present invention, and FIG. 2 is a side view showing the configuration of a seat ring. 1... Valve body, 2... Valve plate, 3... Seat ring.

Claims (1)

[Scope of Claim for Utility Model Registration] A valve plate is rotatably disposed within an annular valve body, and an annular elastic seat ring is disposed between the inner circumferential surface of the valve body and the outer circumferential surface of the valve plate when the valve is opened for sealing. In a chime-shaped valve designed to function as a seat ring, fine fibers of polytetrafluoroethylene are knitted into an annular bundle, and this is arranged in an annular storage part opened on the outer circumferential surface of the valve plate. , a chime-shaped valve formed by forming a metal touch seal portion where the inner circumferential surface of the valve body and the outer circumferential surface of the valve plate are in contact with each other at a portion adjacent to the seat ring.