JPS5827425B2 - valve seat - Google Patents

Description

[Detailed description of the invention] The present invention relates to a valve seat.

Conventionally, rubber materials are often used for the seats of valves such as gate valves and ball valves.

For example, to explain this with respect to the gate valve shown in FIG. is pressed against the gate valve body 6 by a spring 5.

The gate valve body 6 is moved up and down by the stem 7 to open and close the gate valve.

An 01J ring 8 is attached to the seat retainer 2 to seal the fitting portion with the retainer box 4.

The sheet 1 is made up of a relatively soft 01J ring made of rubber, as shown in FIG. 2, or a rubber ring 9 combined with an O-ring made of Teflon or nylon, which is a hard synthetic resin material, as shown in FIG.

Also, when the fluid is sealed with the 01J ring-shaped sheet 1 made of rubber material, the contact surface pressure between the sheet 1 and the valve body 6 is as shown in Fig. 4, and the sheet 1 protrudes 12 due to the influence of the fluid pressure 19. will occur.

In the case of high pressure fluid, in order to prevent this protrusion 12, a backup ring 13 is also used as shown in FIG.

However, in the case of FIG. 2, the seat 1 is made of only a rubber O-ring, so there are the following drawbacks.

■ In the operation of the gate valve body 6, starting resistance and frictional resistance are large.

(2) The contacting rubber sheet 1 may be stretched by the operation of the gate valve body 6, and the sheet 1 may fall off from the seat retainer.

(2) When a high-pressure fluid is sealed, the seat 1 sealed in the gap between the gate valve body 6 and the seat retainer 2 is pushed out by the fluid pressure, and the seat 1 breaks.

To prevent this, a backup ring 13 must be used.

(Fig. 5) ■ When the gate valve 6 is not operated for a long period of time, the rubber sheet 1 that is in contact with it sticks to the gate valve body 6.

Furthermore, in the case of FIG. 3, the 01J ring of the seat 1 and the comb ring 9 are separate parts, making it difficult to attach the valve holder, and moreover, accidents are likely to occur during long-term use.

In the present invention, a core material made of a hard synthetic resin material such as Teflon or nylon with low adhesiveness is placed on a portion of the surface of the seat, approximately in the center of the surface contact area with the surface of the valve body such as a gate or ball that slides with the seat. This method solves the above-mentioned drawbacks by burying the core material so that it is exposed, and the basic technical idea is to have the core material have both a backup function and an anti-adhesion function.

The structure of the sheet of the present invention will be explained in detail with reference to examples. As shown in FIGS. 6 and 7, a Y-shaped core 10 made of Teflon and a rubber material 11 attached to the outside of this core
'It is a J-thong-shaped sheet.

10a to each piece 10-1 of the Y-shaped core 10, 10a to 10-2
b. Holes 10c are provided in 10-3 at equal intervals over the entire length of the ring.

A rubber material 11 is vulcanized and molded onto this using a mold.

To bond Teflon and rubber, the surface of Teflon is treated with cement, a phenolic adhesive is applied, and the above-mentioned vulcanization molding is performed to ensure strong adhesion.
0a.

Since the rubber 11 is integrated through 10b and 10c, it is bonded more firmly than the above-mentioned bonding, and a 01J-shaped sheet is formed.

Note that the holes 10a and 10b of the Y-shaped core 10.

The arrangement of the sheets 10c may be a staggered arrangement as shown in FIG. 6, or another arrangement, and the shape of the sheet may be not only an 01J ring shape but also a ring shape with a rectangular cross section as shown in FIG.

Furthermore, the material of the core 10 is not limited to Teflon, but may also be nylon or other synthetic resin material.

Holes 10a, 10b, and 10c are provided in the core 10 to strengthen the adhesion between the core 10 and the rubber material 11, but as shown in FIG. The groove 15 may be provided to hold the vulcanized rubber material 11 to further strengthen the adhesion to the rubber.

Next, to explain the function of the sheet of the present invention, the first
0 and 11 show the seat 1 of the present invention attached to a gate valve, and only the main parts are shown for the sake of simplicity.

In FIG. 10, the seat 1 is shown in a free state where it is not pressed against the gate valve body 6, and the seat cross-sectional diameter is made such that D>H with respect to the depth H of the groove of the seat retainer 2. It protrudes from retainer 2 by D−H=h.

However, when the valve is closed and the seat 1 is pressed against the gate valve body 6 as shown in FIG.
Sealing is performed by creating a surface pressure in an attempt to repel the contact surface with the gate valve body 6, but since the core 10 of the seat 1 is also in contact with the gate valve body 6 with a certain surface pressure, it cannot be used in high-pressure fluid. It also acts as a backup ring as shown in FIG. 5, and when the gate valve body 6 is operated, the core 10 of the seat
Since the gate valve body 6 slides on the contact surface between the gate valve body 6 and the gate valve body 6, the gate valve body 6 can be easily operated.

Further, even when the gate valve body 6 is not operated for a long period of time, since the core 10 is mainly in contact with the gate valve body 6, sticking can be minimized.

Further, since the core 10 is embedded in the rubber sheet, it will not be stretched by the operation of the gate valve body 6 and will not fall off from the seat retainer.

FIG. 12 shows an embodiment in which the seat 1 of the present invention is attached to a ball valve.

In FIG. 12, 2 is a sea 1-IJ retainer, 3 is an ARA cooling ring, 16 is a spring, and 17 is a ball valve body.

In a ball valve as well, the seat 1 of the present invention can provide a good seal against the sliding ball valve element 17, as in the ball valve described above.

The sheet of the present invention has a Y-shaped core 10 made of synthetic resin embedded in a rubber sheet as shown in FIGS. 6, 7, and 9; The T-shape is used to ensure accurate embedding at a predetermined location when embedding by vulcanization.

Since the core 10 to be buried may be exposed on a part of the surface of the surface contact area between the seat 1 and the sliding valve body, a T-shaped core 18 is placed in a rubber sheet as shown in FIG. May be buried.

Similar to the T-shaped core 10, the core 18 is provided with a hole 18a or a groove (not shown) having ears to strengthen the adhesion to the rubber material 11.

In addition, the square ring-shaped sheet shown in Fig. 8 also has a ■-shaped core 1.
8 may be buried.

As detailed above, the present invention has the following advantages.

■ The contact area with the operating valve body has low frictional resistance.

■ The seat is not stretched by contact with the operating valve body and does not fall off the seat retainer.

■ In the case of valves that seal high-pressure fluids, the seat does not protrude due to fluid pressure, so it provides reliable sealing performance for both low-pressure and high-pressure fluids.

■ Adhesion between the seat and the valve body can be minimized even when the valve body is not operated for a long period of time.

■ Since the core material is wrapped in rubber material, it is not affected by fluid slurry or erosion.

[Brief explanation of drawings]

Figure 1 is a longitudinal sectional view of the gate valve, Figures 2 and 3 are longitudinal sectional views of the main parts of a conventional seat attached to the valve, and Figure 4 is a longitudinal sectional view of the main part of the gate valve.
The figure shows the state of contact surface pressure between a conventional valve seat and a valve body. Figure 5 is a vertical sectional view of the valve seat with the backup ring attached, Figures 6, 7, 8, 9 and 1.
3 is a sectional view of a valve seat according to the present invention, FIGS. 10 and 11 are longitudinal sectional views of main parts of the valve seat of the present invention attached to a gate valve, and FIG. 12 is a cross-sectional view of the valve seat of the present invention attached to a ball. FIG. 3 is a vertical cross-sectional view of the main parts attached to the valve. 1 is a seat, 6 is a gate valve body, and 10 is a T-shaped core. 10a, 10b, 10c, 18a are guide holes, 14 is an ear part,
15 is a groove, 17 is a ball valve body, and 18 is a T-shaped core.

Claims (1)

[Scope of Claims] 1. In a rubber seat of a valve, a core made of a hard synthetic resin material is provided so that a portion of the surface is exposed at approximately the center of the surface contact area between the seat and the surface of the sliding valve body. A valve seat made of buried material. 2. The valve seat according to claim 1, characterized in that a continuous hole is provided in the core material. 3. The valve seat according to claim 1, wherein the core material is provided with a groove having ears.