JPH0124954B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of sealing a valve gland section applied to a valve that controls fluid flowing in a pipe.

There are many different types of valves, and they are widely used in various equipment, devices, machinery, and the like. However, valves control fluids such as gases and liquids, and leakage around the valve shaft used to control the flow of this fluid poses a problem.

Therefore, conventionally, as a means to prevent leakage around the valve shaft, a gland part is formed between the valve body and the valve shaft that passes through the valve body, and a gland packing is interposed in this gland part. It is held down with a presser foot to prevent leakage from around the valve shaft.

However, if the valve controls a fluid that causes corrosion problems, the valve shaft itself may corrode, or the gland packing may deteriorate, resulting in leakage problems over long-term use. occurs. For example, if the valve is a seawater valve that controls the seawater used to cool the coke oven gas to the high temperatures generated by the coke oven, the valve shaft may become damaged during use, even if there are no leakage problems at the beginning of use. Corrosion occurs, and the gland packing also deteriorates, causing water leakage problems, causing various problems such as corrosion of surrounding equipment, blockage of the ammonium water line due to calcium carbonate crystals, and an increase in the amount of ammonium water processed. Furthermore, when the valve shaft corrodes, it becomes difficult to completely prevent water leakage even if a new gland packing is used, and there is a problem that the life of the valve itself is shortened.

In view of this, the inventors of the present invention have conducted extensive research on sealing methods in the valve gland section and ways to extend the life of the valve itself. As a result, the present inventors have developed a liquid silicone rubber with flowability that is approximately the same as the shape inside the gland section. By using a shaped elastic gland packing to make airtight contact with the valve shaft, it is possible to reduce corrosion of the valve shaft in the gland area, and to prevent water leakage even if corrosion occurs on the valve shaft. We have discovered that this can be completely prevented, and have arrived at the present invention.

That is, in the present invention, an elastic gland packing made of liquid silicone rubber having fluidity and molded in substantially the same shape as the inside of the gland is interposed in the gland section of the valve, and the elastic gland packing is connected to the gland using a packing holder. This is a method of sealing the valve gland part by pressing it into the valve gland part, and in a preferred embodiment, liquid silicone rubber that cures at room temperature is directly injected into the gland part to form an elastic gland packing. This is a sealing method.

In the present invention, the liquid silicone rubber used to mold the elastic gland packing has fluidity, and when molding the elastic gland packing, it is possible to mold it into every corner of the mold and valve gland that serve as the prototype. It is fine as long as it flows and hardens.
It may be a one-liquid type or a two-liquid type.
As this liquid silicone rubber, it is preferable to use a type that hardens at room temperature.
Product name “SH9550RTV” manufactured by Silicone Co., Ltd.
"SH9552RTV", "SH9555RTV",
Examples include "SH9556RTV".

In addition, in the method of molding an elastic gland packing using the liquid silicone rubber mentioned above, it is necessary to mold it into approximately the same shape as the inside of the gland, and it is preferable to use the valve itself before installation to mold it into the gland. It is best to inject and mold, or for a valve in the middle of use, it is best to directly inject into the gland of the valve and seal it at the same time as molding.

According to the present invention, since elastic silicone rubber molded into substantially the same shape as the inside of the gland is used as the gland packing, airtightness between the valve shaft and the valve shaft is improved, and the gland is formed. This reduces the chances of the valve shaft part coming into contact with fluid, which can significantly suppress corrosion of this part of the valve shaft. If there is an unavoidable gap caused by dirt etc. between the
Furthermore, even if the packing in contact with the valve shaft wears out due to rotation of the valve shaft, the elastic gland packing is pressed by the packing holder and elastically deforms, even if there is a small gap. This can be hermetically sealed, resulting in a significantly longer lifespan of the valve itself.

Hereinafter, the method of the present invention will be specifically explained based on examples shown in the accompanying drawings.

Example 1 In FIGS. 1 and 2, an example of a valve to which the method of the present invention is applied is shown. This valve is a seawater valve for controlling seawater used when cooling high-temperature coke oven gas generated from a coke oven, and consists of a valve body 1 and a valve shaft 2 that passes through the valve body 1. A gland part 3 is formed in between, and a gland packing 4 is interposed in this gland part 3, and the structure is such that the gland packing 4 is pressed into the gland part 3 with a packing presser 5. .

The above-mentioned seawater valve has been installed in an indirect cooler of a coke oven and has been used for eight years, and the valve shaft 2 has suffered considerable corrosion.

Therefore, first, we used a new seawater valve that is the same as the seawater valve above, and injected Toray silicone rubber (product name: SH9555RTV, manufactured by Toray Silicone Co., Ltd.) into the gland part and hardened it to form an integrated elastic gland packing 4b. This elastic gland packing 4b was cut as shown in FIG. 3 and removed from the seawater valve used as a mold, to produce an elastic gland packing 4b.

Next, remove the seal holder 5 of the seawater valve built into the indirect cooler, remove the used gland packing 4a, fit the newly molded elastic gland packing 4b into the gland part 3, and press the seal holder 5 again to remove the used gland packing 4a. The elastic gland packing 4b was pressed into the gland portion 3 to perform sealing.

After sealing the gland of the seawater valve in this way, when seawater was passed through the seawater valve, leakage of seawater was completely prevented, and after three
No leakage of seawater has occurred over the past year, and it has been found that stable use can be achieved over a long period of time.

As a comparative example, a commercially available asbestos-based gland packing was used to seal another seawater valve that was installed in an indirect cooler at the same time as the seawater valve used in the above example, and the leakage of seawater was completely prevented. could not be prevented. As a result of investigating the cause of this, as shown in Figure 4a, the conventional gland packing 4a has poor elasticity, and even when pressed with the packing holder 5, a gap is created between it and the corroded valve shaft 2. It turned out to be.

On the other hand, according to the method of the present invention, FIG.
As shown in the figure, when the elastic gland packing 4b is pressed down with the packing presser 5, the elastic gland packing 4b is elastically deformed within the gland portion 3 and comes into airtight contact with the valve shaft 2, thereby completely preventing water leakage. .

Example 2 A seawater valve of the same type as the above-mentioned seawater valve, whose valve shaft has significantly corroded and seawater is leaking, was cleaned to remove rust, oil, dust, etc. from the gland. After this, the Toray silicone rubber was directly injected into the gland section and cured to form an elastic gland packing inside the gland section, which was then pressed down with a packing presser to seal. When seawater was passed through this seawater valve, seawater leakage was completely prevented, and no seawater leakage has occurred in the three years since, allowing stable use over a long period of time. It has been found.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a seawater valve to which the method of the present invention is applied, Fig. 2 is an enlarged sectional view of the main part of Fig. 1, and Fig. 3 is a perspective view showing the gland packing of Fig. 2. FIGS. 4a and 4b are explanatory diagrams for explaining the case where the method of the present invention is applied and the case where the conventional method is applied. DESCRIPTION OF SYMBOLS 1... Valve body, 2... Valve shaft, 3... Gland part, 4, 4a, 4b... Gland seal, 5... Seal retainer.

Claims (1)

[Claims] 1. A valve gland sealing method in which a gland packing is interposed in a gland formed between a valve body and a valve shaft passing through the valve body, and the gland packing is pressed into the gland with a packing holder. In the above-mentioned gland part, a closed space is formed by this gland part and the above-mentioned packing holder, and this gland part is used as a mold to form a shape substantially the same as the shape inside this gland part using fluidized liquid silicone rubber. A seal for a valve gland section, characterized in that the elastic gland packing is molded, the elastic gland packing is interposed in the closed space of the gland section, and the elastic gland packing is pressed down with a packing holder, thereby elastically deforming the elastic gland packing and sealing. Method.