JPH0452533Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a gasket ring, which can be inserted between the flanges of a container or pipe whose inner surface is lined with glass to prevent leakage of internal fluid. Regarding the gasket ring.

(Prior Art) Generally, a gasket ring is installed between the joint flanges of piping or between the reaction vessel body and the lid to prevent internal liquid or gas from leaking to the outside. If the liquid flowing inside the pipe is a chemical such as an etching liquid, the gasket ring will be eroded by the chemical, so the inner peripheral surface and both end surfaces of the gasket ring should be coated with tetrafluoroethylene resin, etc. There is.

Fig. 5 shows this type of conventional gasket ring, which consists of an annular core A made of an asbestos joint sheet or a combination of an asbestos felt sheet and this core. It is composed of an outer cover B having a U-shaped cross section that covers the inner circumferential surface of A and the end faces on both sides, and the outer cover B is made of tetrafluoroethylene resin.

(Problem to be solved by the invention) Tetrafluoroethylene resin has excellent heat resistance and chemical resistance, so a gasket ring in which all wetted parts are coated with tetrafluoroethylene resin Will not be affected by liquids or swell. However, because the coefficient of surface friction is extremely small and it also has non-adhesive properties, for example, when the gasket ring is installed between glass-lined flanges, the inside of the pipe or container may be placed under vacuum or reduced pressure. When the container is removed, the negative pressure causes the outer sheath made of tetrafluoroethylene resin to be drawn into the inside of the container from the joint surface, reducing the sealing function.

In order to solve this problem, in the gasket ring shown in Fig. 5, a mounting hole C is drilled through the core A and the outer sheath B, and the gasket ring is fixed with a tightening bolt during installation. ing.

However, if the gasket ring is expected to be corroded by entering the chemical solution through the mounting hole C, the flange joint must be tightened with a clamp. For this purpose, the problem of the jacket being drawn inwards has to be solved by other means.

Therefore, an object of the present invention is to provide a gasket ring that can reliably perform its sealing function without causing the fluororesin sheath to be drawn in even under negative pressure.

(Means for Solving the Problems) In order to achieve the above object, the present invention covers the inner circumferential surface and both end surfaces of the annular core with an outer sheath made of fluorine resin and having a U-shaped cross section. In the covered gasket ring, stop pieces are provided near the outer periphery of both end faces of the outer sheath of the gasket ring, and the inner ends of the stop pieces are locked to the outer periphery of the flange of the object to be sealed. This feature is characterized in that it allows the user to

(Function) Even if an inward pulling force acts on the fluorine resin outer sheath that coats the core, the stop piece provided on the outer periphery of the fluorine resin outer sheath will seal. Since it comes into contact with the outer peripheral edge of the flange of the object to be processed and acts as a stopper, the fluorine resin outer cover is prevented from being drawn inward.

(Embodiments) Hereinafter, embodiments of the gasket ring according to the present invention will be described with reference to FIGS. 1 to 4.

In FIG. 1, reference numeral 1 indicates a gasket ring according to the present invention. It is composed of a U-shaped outer cover 2, and this outer cover 2 is usually made of a tetrafluoroethylene resin film. However, when used in areas that come into contact with various monomers that easily polymerize, such as vinyl chloride, styrene, butadiene, etc., tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) films are preferred. Other tetrafluoroethylene depending on the usage environment.
Films such as hexafluoropropylene copolymer resin (FEP), trifluorochloroethylene resin (CTFE), and vinylidene fluoride (TVDF) can also be used. As shown in Fig. 1, these films are preferably bent into a substantially U-shaped cross section, but are not limited to this, and may also have a substantially V-shaped cross section; It is sufficient that the body A is covered to prevent it from coming into direct contact with the liquid.

The core A is desired to have elasticity, and in the illustrated example, it is composed of asbestos joint sheets 4a, 4b and asbestos felt sheets 5a, 5b, which have a small stress relaxation phenomenon. Further, a corrugated metal plate 6 is interposed between the asbestos joint sheets 4a and 4b to provide elasticity. In this case, the asbestos felt sheets 5a, 5b and the asbestos joint sheets 4a, 4b are bonded together with a rubber adhesive. In any case, various combinations of the materials and thicknesses of these cores A are selected depending on the unevenness and waviness of the glass-lined flange surface, temperature, and pressure. Furthermore, an asbestos joint sheet can be additionally inserted into the core A by adjusting the shims.

The material used for the core A is not limited to the asbestos joint sheet, but may also include rubber, soft metal, synthetic resin, non-asbestos joint sheets, etc., either alone or in combination.

According to the present invention, the stop pieces 3, 3...
3 is installed protrudingly. These stop pieces 3 are connected to the jacket 2
It is fused or bonded with adhesive. For example, if the outer cover 2 is made of tetrafluoroethylene resin, it can be fused by heating and pressurizing small pieces of tetrafluoroethylene resin through a PFA film. In addition, the outer sheath is PFA
For FEP, PVDF, etc., small pieces of the same material may be bonded together by welding or the like.

The example shown in Fig. 4 is the above-mentioned locking piece 3, 3,...3
This is an example in which the screws are mechanically fixed using screws 9a and 9b.
These stop pieces 3 may be made of light metal such as aluminum, rubber, or other general-purpose synthetic resin in addition to the above-mentioned fluorine resin, and there are no particular limitations on the material. Moreover, the number of stop pieces 3 and the gap between the stop pieces can be set as appropriate.

FIG. 3 shows a state in which the gasket ring according to the present invention described above is attached to a flange of a joint of a glass-lined container. That is, the flanges of the containers 11 are brought into contact with each other, and the inner surfaces of these containers 11 are coated with the glass lining layer 1.
2 is formed, and in the gasket ring 1, the outer sheath 2 and the glass lining layer 12 are brought into close contact with each other by the tightening force of the clamp 10, thereby preventing leakage of internal fluid. However, when the internal pressure P ₁ becomes smaller than the external pressure P ₂ , a force acts on the outer jacket 2 to draw it inward between the core A and the glass lining layer 12 . At this time, the outer peripheral edge 13a, 1 of the flange
The inner end of the stopper piece 3 comes into contact with the stopper 3b and serves as a stopper, so that the jacket 2 is no longer drawn inward.

(Effects of the invention) As is clear from the above explanation, according to the invention, stop pieces are provided at positions close to the outer periphery of both end faces of the outer cover made of fluorine resin, and the inner ends of the stop pieces are Since it is fixed to the outer circumferential surface of the flange of the object to be sealed, the fluorine resin outer cover will not be drawn into the container even under negative pressure, and a stable sealing function can be maintained. can.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an embodiment of the gasket ring according to the present invention, Fig. 2 is a plan view of the gasket ring, and Fig. 3 is a cross-sectional view showing the gasket ring in use. 4 is a cross-sectional view showing another embodiment of the present invention, and FIG. 5 is a cross-sectional view of a conventional gasket ring. 1... Gasket ring, A... Core body, 2...
...Sheath, 3... Stop piece.

Claims (1)

[Scope of utility model registration request] In a gasket ring in which the inner circumferential surface and both end faces of an annular core body are covered with a fluorine resin outer sheath having a U-shaped cross section, the outside of both free ends of the outer sheath of the gasket ring is A plurality of stop pieces are provided at a predetermined interval in the circumferential direction on the outer surface near the periphery, and the inner ends of these stop pieces are fixed to the outer peripheral surface of the flange of the object to be sealed. A gasket ring characterized by: