JPH0540377Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement to a bellows valve with a leakage confirmation function.

[Prior Art] Conventionally, in this type of bellows valve, as shown in FIG. A disc 6 that sets the communication port 5 to a fully closed position, an intermediate position, or a fully open position is moved to follow, and this disc 6 and the stem 2
The primary sealing part around the stem 2 is sealed with a bellows 7 that separates the liquid used from the atmosphere, and the secondary sealing part with the bonnet 8 around the stem 2 inserted into the body main body 3 is sealed with a gland packing 9.
Some have a configuration in which the gland packing 9 can be further tightened by a gland bush 13 which is pushed in and adjusted by a gland plate 10, a gland bolt 11, and a gland nut 12.

[Problems to be solved by the invention] However, in the case of the bellows valve of the conventional structure described above, even if the bellows 7 of the primary seal part fails due to fatigue and the used liquid leaks, the gland packing 9 of the secondary seal part Although the leakage can be stopped to a certain extent, it cannot be confirmed from the outside, and as time passes, the liquid used may leak from the secondary seal part made by the gland packing 9 and leak to the outside. If the product is leaked, it will be difficult to stop the leakage even if the gland packing 9 is tightened, and as a result, if the product uses harmful fluid, it is necessary to immediately shut down the line and replace or repair the parts. Then a problem arose.

[Purpose of the invention] The invention was developed under the above circumstances, and its purpose is to enable easy confirmation from the outside of the leakage of the liquid used at the primary seal. Our purpose is to provide a bellows valve.

[Means for Solving the Problems] The bellows valve according to the present invention has a through hole formed in a bonnet at a position between a primary sealing part and a secondary sealing part, and an inner surface sealed to the through hole. The structure includes a glass plate with a roughened surface and a leak confirmation window made of a glass plate with a roughened surface.

[Function] In other words, with the above configuration, the present invention provides a leakage confirmation window between the primary seal portion and the secondary seal portion, thereby preventing damage to the primary seal due to fatigue failure of the bellows, etc. Even if a leak occurs in the part, it can be easily confirmed from the outside, and it can be detected early before leakage occurs from the secondary seal part by the gland packing. In other words, if there is no liquid inside the glass plate in the leak confirmation window, the glass plate will appear cloudy due to the diffuse reflection of external light by the rough inner surface, but this may be due to damage to the primary seal made of bellows. Therefore, when the working liquid leaking from this primary seal wets the inner rough surface of the glass plate, the external light is transmitted to the liquid, making the glass plate appear dark. The presence or absence of leakage in the seal portion can be easily identified.

[Example] Hereinafter, the present invention will be described in detail with reference to an example shown in FIGS. 1 and 2. In the illustrated embodiment of the present invention, parts having the same structure as those of the conventional bellows valve shown in FIG. 3 are denoted by the same reference numerals, and a description thereof will be omitted.

That is, as shown in FIG. 1, the bellows valve according to the present invention includes a primary seal portion in which the periphery of the disk 6 and stem 2 is sealed with the bellows 7, and the stem 2 and bonnet 8 that are inserted into the body main body 3. A leak confirmation window 20 is provided between the secondary seal portion and the secondary seal portion whose periphery is sealed with a gland packing 9.

The leakage confirmation window 20 is formed through a through hole 2 formed through the bonnet 8, as shown in FIG.
A glass plate 23 is fitted into the glass plate 1 through a gasket 22, and this glass plate 23 is held watertight by a pressing member 24. In this case, the glass plate 23 is
The back surface 23a that is in contact with the liquid is made rough like polished glass, so that when there is no leakage, the glass plate 23 reflects external light diffusely and appears white, and when a leakage occurs, the glass plate 23 appears white. There is a glass plate 2
When leaked liquid comes into contact with the back surface 23a of the glass plate 23, the refractive index at the interface between the glass plate 23 and the liquid decreases, allowing external light to pass through without causing the aforementioned diffuse reflection. Therefore, the occurrence of leakage due to damage to the bellows 7 of the primary seal portion can be easily identified.

It should be noted that the present invention is not limited to the above embodiments in any way, and it goes without saying that various modifications may be made without changing the gist of the present invention.

[Effects of the invention] As is clear from the above explanation, according to the invention, when the rough surface formed on the inside of the glass plate is in contact with air, external light is diffusely reflected by this rough surface, resulting in cloudiness. By using the optical phenomenon that when the rough surface is in contact with liquid, external light passes through this glass plate and it appears dark, it is possible to check whether or not the liquid used is leaking from the primary seal. Leakage from the secondary seal can be identified before it occurs.

In addition, since leakage from the primary seal can be detected early before leakage occurs from the secondary seal due to the gland, the gland can be retightened quickly before leakage occurs from the secondary seal. By retightening, it is possible to take measures such as preventing leakage from the secondary seal portion or delaying the time until the leakage occurs, and preparing for repair during this time.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional side view of the main part showing an embodiment of the bellows valve according to the present invention, Fig. 2 is an enlarged sectional view of the main part in section A of Fig. 1, and Fig. 3 is the main part of a conventional bellows valve. FIG. 1... Handle, 2... Stem, 3... Body main body, 4... Distribution path, 5... Communication port, 6... Disc, 7... Bellows (primary seal part), 8...
Bonnet, 9...Gland packing (secondary seal part), 20...Leakage confirmation window.

Claims (1)

[Scope of utility model registration request] a disk disposed in a valve chamber formed between a body main body and a bonnet integrally connected thereto to open and close a flow passage; a primary seal portion consisting of a bellows on the outer periphery of the stem and both ends of which are hermetically fixed to the inner surface of one end of the disk and the valve chamber; and an axial hole of the bonnet and an axial periphery of the stem. In the bellows valve, the bellows valve is provided with a secondary seal part made of a gland packing that seals between the primary seal part and the secondary seal part, and a through hole opened in the bonnet at a position between the primary seal part and the secondary seal part; A bellows valve characterized by having a glass plate with a rough inner surface and a leak confirmation window.