JPS6014662A - Construction of gate valve fixing disc at full opening - Google Patents

Abstract

PURPOSE:To surely suppress vibration of a disc caused by fluid flowing into a bonnet, by providing an adapted member for fixing a jaw part of the disc to be fixed in an internal upper part of the bonnet. CONSTITUTION:A spacer 15 being used as an adapted fixing member is mounted to be integrally welded extending over the internal surface of a bonnet 6 and the bottom part of a neck bush 12, and the spacer 15 is oppositely faced to a disc jaw part 14. A thickness of the spacer 15 is designed and determined so that the spacer 15 may be adapted to an upper surface of the disc jaw part 14 when a gate valve is in its full opening condition. When the gate valve is placed in its full opening condition, a disc 5 is never moved by supporting an upper end of the disc jaw part 14 to be fixed to the spacer 15 even if the side pressure of fluid acts in the bonnet 6.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] This invention relates to a fully open gate valve structure installed immediately downstream of a pump elbow, etc. in a fluid system used in a nuclear or thermal power plant. In particular, in order to counter the lateral stress of the fluid flowing into the valve bonnet due to disturbance of the installed fluid by the elbow bolt, the upper end of the disk when the valve is fully open is immobilized by a fixed body such as a spacer installed on the inner surface of the valve bonnet. This invention relates to a gate valve structure in which a disk is fixed when the bonnet is fully open, which prevents lateral vibration of the valve body within the valve bonnet h due to fluid flow.

[Background of the invention]

As is well known, a large number of pipes are used in nuclear power plants, hot spots, etc., and many of the pipes connected to feed pumps have elbows.

In various designs, a gate valve is provided immediately downstream of the elbow.

The embodiment shown in FIG. 1 shows an example of a piping system in which the type gate valve 1 is installed, and the upstream pump 2
A control valve 3 and an elbow 4 are interposed in series immediately downstream of the pump 2 for the purpose of controlling the flow rate of the pump 2.

A gate valve 1 is provided immediately downstream thereof.

The gate valve 1 is normally fully closed only during maintenance of the pump 2, and is fully opened while the pump 2 is in operation.

The fluid discharged from the pump 3 passes through the control valve 3,
It is bent at the elbow 4 and flows into the gate valve l in a turbulent flow.

By the way, in the conventional valve structure mentioned above, among the normal gate valves, a wedge gate valve is generally used. It has a wedge-shaped structure that makes it easy to insert the seat.

The reason for using a lid and a wedge-type gate valve is to eliminate leakage from the valve even when the pressure is low when the valve is fully closed, and to facilitate maintenance of the pump.

As shown in FIG. 2, the mechanism of the gate valve 1 is that when the valve is fully open, the disk 5, which is the main body of the valve, is located inside the bonnet 6 and suspended from the stem 7, and by lowering the stem 7, The disk 5 descends along the disk guide 8,
Finally, it enters the sheet 10 of the flow section 9 and closes in the wedged state.

On the other hand, when the valve is fully open, the disc 5 is connected to the stem 7.
There is nothing to restrain the disk 5 except that it is suspended by the disk 5.

The upper part of the stem tip 11 contacts the neck bushing 12 to maintain the fully open position, and a gland packing 1 is attached to the upper part of the neck bushing 12 along the stem 7.
3, which prevents the fluid within the valve from leaking to the outside along the side surface of the stem 7.

Further, by bringing the neck bush 12 into contact with the stem tip 11, the fluid is seamed by a bank sheet.

That is, the gland packing and back sheet prevent fluid from flowing outside.

Regarding the connection between the disc 5 and the stem 7, the upper end of the disc 5 is shaped like a chin, the so-called disc chin 14, as shown in Fig. 3.4. 14, the stem tip 11 is inserted from the side,
The stem 7 and the disc 5 are connected, and a clearance C is formed between the upper end of the disc 5 and the neck bush 12.

As mentioned above, when the valve is fully open, the upper part of the stem tip 11 comes into contact with the neck bushing 12, so the disc 5
Since it is in a suspended state, when pressure is applied to the disc 5 from the side due to the pressure of the fluid, the disc 5 swings through the clearance C.

In particular, the gate valve 1 is next to the control valve 3 as shown in FIG.
In the case where the elbow 4 is provided directly downstream, turbulent flow occurs, and the turbulent flow that enters the gate valve 1 also enters the bonnet 6, exerting a pressing force against the disk 5 from the side. In such a case, the disk 5 will be tilted in a cantilevered manner, and therefore, if the lateral stress is small and the disk 5 is tilted a little,
Immediately, the restoring force acts on it and it tries to return to its position.

In this way, the disk 5 makes a swinging pendulum movement using the joint with the stem tip 11 as a fulcrum.

In this case, the disc jaw portion 14 and the stem tip 11
There is unavoidable play in the connection between the two due to manufacturing and assembly. Therefore, when the disc 5 vibrates, the contact part shifts and wear begins. If this state continues for a long time, the wear progresses and the disc jaw There is a disadvantage that there is a possibility that the joint portion of the portion 14 may be damaged, and furthermore, there is a disadvantage that the durability is shortened.

In severe cases, leakage may occur, making it difficult to ensure complete closure, and there is also the problem that secondary leakage occurs outside of the periphery of the stem 7.

[Purpose of the invention]

The purpose of this invention is to solve the technical problem of the disk of the gate valve for full open use, which is located immediately downstream of the elbow, etc., based on the above-mentioned prior art, and to solve the problem,
As a result, it is possible to reliably suppress the vibration of the disc caused by the fluid that has entered the bonnet, preventing leaks,
It is an object of the present invention to provide an excellent fully closed disk fixed gate valve structure that improves durability and is beneficial to piping applications in various industries.

[Summary of the invention]

In order to solve the above-mentioned problems, the outline of the present invention, which is based on the above-mentioned claims in accordance with the above-mentioned object, is to solve the above-mentioned problems by using lateral pressure caused by the fluid flowing through the disk of the gate valve provided directly below the elbow etc. when the valve is fully opened. In order to prevent the vibration that occurs, by installing a fixing material such as a spacer for the disc jaw part at the bottom of the neck bushing, the disc jaw part is fixed to the bonnet when the valve is fully open, and the vibration of the disc is completely prevented. In this way, technical measures have been taken to prevent wear and damage to the joint between the disc jaw and the bonnet, improve durability, and reliably prevent leakage.

[Embodiments of the invention]

Next, an embodiment of the present invention will be described below based on the drawings from FIG. 5 onwards.

In addition, the same reference numerals will be used to describe the same parts as those in FIGS. 1 to 3.

In the embodiment shown in FIG. 5, a spacer 15 as an abutting fixing member is integrally attached to the conventional structure by welding across the inner surface of the bonnet 6 and the lower part of the neck bushing 12, and is opposed to the disc jaw portion 14.

The thickness of the spacer 15 is designed and determined so that the spacer 15 comes into contact with the upper surface of the disc acoustic section 14 when the gate valve 1 is fully open. The other configurations are substantially the same as the conventional configuration shown in FIG.

In the above configuration, when the gate valve 1 becomes fully open,
The disk 5 does not move even if side pressure of the fluid is applied within the bonnet 6 because the upper end of the disk acoustic portion 14 is fixedly supported by the spacer 15.

Therefore, there is no vibration of the inner surface of the disk jaw portion 14 when it is fully opened, and there is no wear or damage caused by the vibration.

When the valve is fully open, the upper surface of the disc jaw portion 14 comes into contact with the spacer 15, so that the sealing of the bank seat described above due to the upper part of the stem tip 11 coming into contact with the neck bushing 12, which was the case in the conventional valve mechanism, is achieved. The effect becomes weaker.

However, the seal on the side of the stem 7 can be made sufficiently with the gland palatine 13.

Next, in the embodiment shown in FIG. 6, as the abutment fixing material,
The neck bushing 12, which has been conventionally provided in place of the spacer 15, is changed to a headed neck bushing 12f with a flange-like head 16 formed at the bottom. The neck bush 12 is interposed in place of the neck bush 12, and is integrally welded to the base of the bonnet 6 to prevent rotation.

In this embodiment, the stem 7 only needs to be fitted with the disc jaw portion 14 at the stem tip 11, as in the above-described embodiment.

When the valve is fully open, the disc jaw can be fixed in contact with the flange-shaped head part 16 of the neck bush 12', so that vibrations of the valve can be prevented even in response to lateral pressure.
Wear and the like caused by this are prevented.

Structurally, the number of parts does not change, and maintenance requires only the neck bushing to be replaced.

Furthermore, in the embodiment shown in FIG. 7, countermeasures are taken against Banksy, which is not necessarily sufficient in each of the above embodiments, namely, the stem 7, the stem tip 11, and
The structure of the disc jaw part 14, neck bush 12, etc. is as follows.
Same as the conventional configuration, a disc backing plate 17 as a suitably flexible abutment solid foot is integrally welded to the upper inner surface of the bonnet 6 with respect to the disc jaw part 14 when the valve is fully opened.

Therefore, when the valve is fully open, the stem tip 11 is connected to the neck bush 12.
At the same time, the disk chin part 14 is pushed into the disk folding board 17 and fixed in close contact with the bank sheet so that the bank sheet does not function.

Here, by making the disk folding plate 17 flexible as described above, it is possible to securely press and fix the disk jaw part 14 at the same time as scraping the bank sheet, thereby preventing vibration and suppressing damage. do.

Therefore, in this embodiment, it is possible to fix the disk 5 while maintaining the conventional sealing function of the bank sheet.

〔Effect of the invention〕

According to this invention, firstly, in the gate valve, an abutment fixing member such as a spacer is interposed between the disk jaw portion of the disk and the corresponding inner surface of the bonnet, so that the disk is attached to the bonnet when the gate valve is fully open. In addition to being able to fix the gate valve in place, there is also an effect that the sealing function of the gate valve is not impaired when it is fully closed.

In addition, by fixing the disc to the bonnet when the gate valve is fully open, the disc jaw part will not vibrate even if it is installed under turbulent flow downstream of a control valve, elbow, etc. in the fluid flow path.
Therefore, there is an excellent effect that wear and damage are less likely to occur and durability is improved accordingly, and there is also an effect that no leakage occurs.

Furthermore, since the disk is fixed when the valve is fully open, even if there is pipe vibration, the disk only vibrates together with the stem, which eliminates wear at the disk and stem joint. It is played.

By fixing the disk when the valve is fully open by using a fixed phase such as a spacer or disk plate, the structure is simple and does not require high costs. Another advantage is that the sealing effect of the sealing sheet and gland packing, which was used to prevent external leakage, is not impaired.

[Brief explanation of drawings]

Figure 4 is an enlarged perspective view of part B in Figure 3, and Figures 5 and below are detailed explanatory views of the present invention, and Figure 5.6. FIG. 7 is a partially enlarged sectional view of each embodiment. 1... Disc gate valve, 5... Disc, 14...
...Disc jaw part, 6...Bonnet, 15, 16
゜17...Fixing material for drawing and contact, 15...Spacer, 1.
2...Nei J (5 g4 figure)

Claims (1)

[Claims] 1. In a fully open disk-fixed gate valve structure that is installed at a turbulent flow generation site in a fluid flow path, the contact fixing member for the disk jaw portion of the disk of the gate valve is located at the top of the bonnet. A fixed disk gate valve structure when fully open, characterized by being fixed internally. 2. The fully open disk fixed platform cage structure according to claim 1, ML2, wherein the abutting fixing member is a spacer for the upper surface of the disk jaw portion. 3. The earth and mud abutting fixing material is the lower end flap 4 of the neck push, and the abutting fixing material is a dakikomi board facing one part of the disc jaw part. Disc fixed gate valve structure when fully open as described.