JPS58131477A - Valve - Google Patents

Abstract

PURPOSE:To make it possible to prevent a wiper ring from jumping out while reducing a flow velocity on the wiper ring when a valve is opened by discontinuously cutting the one part of a wiper ring upper part in a ball valve, etc. CONSTITUTION:When a valve body 2 is stopped and a fluid passage 3 is opened or closed, a wiper ring 23 prevents a solid material from invading into a space between the wiper ring and a seat 14, while when the valve body 2 is turning, a solid material stuck to the valve body 2 is scraped off to similarly prevent the invasion of the solid material. Further, when the valve body 2 is turned to a II position, the seat 14 separates from the peripheral surface of the valve body, the fluid with a pressure P1 within a upstream fluid passage 3 passes through a notch part 25 formed on the upper part of the wiper ring 23, and flows into a cavity B. Hereby, the pressure between the wiper ring 23 and the seat 14 comes near P1, and the flow speed of a fluid passing through the clearance between the wiper ring 23 and the valve body 2 is reduced when the valve is opened, preventing the wiper ring from jumping out.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to valves, and particularly to the structure of valves such as ball valves and gate valves in which the circumferential surface of the valve body slides against a seat when the valve body opens and closes.

In recent years, pipelines have been used as a means of mass transportation of natural gas and crude oil, and many ball valves and gate valves are installed on these pipelines, but natural gas and crude oil contain impure solids. If these impurities reach the seat, there is a risk of damaging the seat and the circumferential surface of the valve body when the valve body is opened and closed.

In order to solve this problem, the present inventors have developed a ball valve as shown in FIG.
A wiper ring 32 smaller than 0 was installed, and a structure was created in which the wiper ring 32 prevented impurity solids from entering the sheet 30 [Utility Model Application No. 54-41858].

]. The initially created one had two large and small annular grooves 34 and 35 on the front surface of the annular seat retainer 31 facing the valve body 33.
The annular sheet 30 is screwed into the annular groove 34 with a large diameter, and the simple endless wiper ring 32 is press-fitted into the annular groove 35 with a small diameter. I came to discover that there is a problem.

That is, the problem is that the blowdown side of the wiper ring (when the valve body 33 is opened, the blowdown side of the wiper ring
The side that first faces the fluid passage hole 36 of No. 3;
The part shown in the figure is this blowdown side. )
This is a phenomenon in which the particles protrude from the annular groove.

The inventors analyzed this wiper ring popping phenomenon and found that the cause lies in the following points.

That is, when the valve body 33 is closed (indicated by the symbol ■), the fluid in the upstream side A flows into the annular groove 35 for inserting the wiper ring, wraps around the rear surface 32a of the wiper ring 32, and flows against the wiper ring 32. A back pressure equal to the pressure P1 on the upstream side A is applied. Now, move the valve body 33 in the direction of the arrow (
When the valve body 33 is rotated in the valve-opening direction), the position of the fluid passage hole 36 of the valve body 33 changes in the order of symbols →■→■→1v→V. In the position of the valve body 33, the seat 30
is in close contact with the circumferential surface of the valve body 33 and is almost completely sealed, but when the seat 30 reaches the position indicated by symbol 3, the seat 30 begins to come off from the valve body 33.

On the other hand, since the wiper ring 32 is not intended for sealing itself, its sealing performance is poor. Therefore, from the time the valve body 33 reaches the position marked with symbol ■, the fluid on the flow side A flows between the wiper ring 32 and the valve. It passes through the gap with the body 33 and flows out to the cavity B side where the pressure is approximately equal to atmospheric pressure po. At this time, if the pressure difference between the pressures P1 and po is large, for example, if the pressure difference is 100 kg/cm2, the velocity of the fluid passing in front of the wiper ring will be close to the speed of sound, and according to Bernoulli's theorem or the atomizing Similar to the phenomenon, the front surface of the wiper ring is rapidly reduced to a pressure sufficiently lower than the pressure PI. Therefore, the wiper ring 32 has grooves 35 due to the back pressure applied to its rear surface and the reduced pressure on its front surface.
trying to jump outside. By the way, wiper ring 32
is in contact with the circumferential surface of the valve body 33, that is, the valve body 33
It will not jump out of the groove 35 while being supported by. However, at the moment when the valve body 33 reaches the position indicated by the symbol (3), the blowdown side of the wiper ring 32 loses support from the valve body 33, and at the moment it jumps out of the groove 35 due to the above pressure difference.

Therefore, in order to prevent the wiper ring 32 from jumping out of the groove 35, the back pressure of the wiper ring must be reduced, or when the fluid passes through the front surface of the wiper ring when the valve is opened, the pressure on the seat side of the wiper ring must be reduced. The fluid flow rate may be reduced by increasing the pressure to a value close to pressure P1, or both may be achieved.

Therefore, the technical problem to be solved by the present invention is to increase the seat side pressure of the wiper ring to a value close to the fluid pressure Pl when the fluid passes through the front surface of the wiper ring when the valve is open, thereby decelerating the fluid flow speed. It consists in doing.

In order to achieve this technical problem, the present invention has a structure in which a part of the upper part of the wiper ring is cut out discontinuously.

With the above configuration, when the valve is opened, the fluid in the upstream fluid flow passage passes through this notch and goes around between the wiper ring's broken down side and the seat, so that the pressure in front of the wiper ring approaches the upstream fluid pressure. The fluid flow passing between the plow wiper ring and the circumferential surface of the valve seal is slowed to ensure a pressure substantially close to back pressure on the front face of the wiper ring, thereby preventing the wiper ring from popping out.

According to this structure, since the wiper ring is discontinuous, it can be manufactured by bending a linear material into a ring shape, so compared to an endless wiper ring manufactured by integral molding, This is extremely advantageous in terms of manufacturing costs.

Furthermore, since the cutout is formed in the upper part of the wiper ring, it does not have any adverse effect on the effect of preventing the intrusion of impurities that tend to sink under their own weight.

The most preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 shows a vertical cross-section of the main part of the ball pulp. In this figure, 1 is a housing, 2 is a ball-shaped valve body rotatably mounted in the housing around a central axis in the vertical direction (not shown) and has a fluid passage hole 2b, and 3 is formed in the housing 1. The fluid flow path 4 is an annular seat retainer fitted into the housing 1 so as to surround the fluid flow path 3.

The seat retainer 4 is slidable within the housing 1 in the -indoor front-rear direction, and the outer circumferential surface 4 of the seat retainer 4 is
annular grooves 4'b, 4c are formed in the annular grooves 4'b, 4c, and O-rings 5.6 that are closely fitted to the inner circumferential surface 1a of the housing 1 are fitted into the annular grooves 4b, 4C for sealing. Blind holes 7 are provided at regular intervals on the rear surface 4d, and a coil spring 8 is fitted into the blind hole 7 so that the rear end of the coil spring 8 is connected to the vertical 1 of the housing 1.
1b, so that the seat retainer 4 is always urged toward the valve body 2 by the fill spring 8.

An annular outer ring 9 is fitted into the front end outer periphery 4e of the seat retainer 4, and a groove 11 is formed in the front end 9a of the outer ring 9 and the front surface 4'' of the seat retainer 4.
An annular seat groove 12 is formed, and an annular seat 14 is fitted into the seat groove 12 to seal the space between the annular seat groove 12 and the circumferential surface 2a of the valve body 2. Note that the lower part of the rear end surface 9b of the outer ring 9 is connected to the outer circumferential surface 4a of the seat retainer 4.
The backing plate 15 that engages with the annular groove 4g formed in the bolt 1
6, and the outer ring 9 is fixed to the seat retainer 4.

On the front surface 4h of the seat 9 retainer 4, an annular sealant grease supply groove 17 is provided on the radially inner side of the seat member 12, and an annular wiper ring groove is provided on the radially inner side of the sealant grease supply groove 17. There are 18.

One end of a grease supply groove 20 provided in the seat retainer 4 is opened in the sealant grease supply groove 17,
On the other hand, the other end of the sealant grease supply hole 20 is connected to the annular grooves 4b and 4c of the outer peripheral surface 4a of the seat retainer 4.
It opens into an annular shallow dipping 4k formed between the holes. and,
A coupler 21 attached to the housing 1 is installed in the shallow groove 4.
The sealant grease supplied from the coupler 21 is communicated with the sealant grease supply hole 22 of the housing 1. The sealant grease is injected into the annular groove 11 through the shallow groove 4 of the seat retainer 4 and the sealant grease supply hole 20.

On the other hand, a wiper ring 23 having a rectangular cross section is tightly fitted into the wiper ring groove 18, and its front surface 23 is tightly fitted into the wiper ring groove 18.
The inner circumferential corner portion 23a of b is projected forward from the wiper ring groove 18 and is brought into contact with the circumferential surface 2a of the valve body 2. This wiper ring 23 is preferably made of a soft material such as Teflon or aluminum. According to these materials, when rotating the valve body, the peripheral surface 2 of the valve body 2
Hard to damage a.

A discontinuous notch 25 is provided in a part of the upper part of the wiper ring 23. In other words, this wiper ring 2
3 bends a linear material into a link shape, and when viewed as a finished product, a notch 25 is formed between both ends thereof.

According to the embodiment with the above configuration, when the valve body 2 is stationary and the fluid flow passage 3 is opened or closed, the wiper ring 23 is free from solid matter such as sand and scale in the fluid. It prevents it from entering between the sheets 14. Since the wiper ring 23 has a notch 25 at its upper part, the fluid flowing through the fluid flow path 3 flows into the seat 14 side through the notch 25, but impurity solids in the fluid generally Since it moves in the lower part of the fluid flow path 3 by its own weight, impure solids are prevented from flowing into the sheet 14 side together with the fluid.

On the other hand, when rotating the valve body 2 to open and close the fluid flow passage 3, the corner 23a of the wiper ring 23
Since the impure solids adhering to the smaller diameter side of the wiper ring 23 are scraped off, the impure solids do not enter between the wiper ring 9 and the seat 14. Therefore, these solids prevent the seat 14 and the valve body 2 from being The peripheral surface 2a will not be damaged.

When the valve body 2 is rotated in the order of ■→m→■→V from the position indicated by the symbol ■, the seat 14 reaches the position indicated by the symbol ■, as described for the conventional example in FIG. It begins to separate from the circumferential surface of the body 2, and therefore fluid flows from the upstream fluid flow path 3 through the gap between the wiper ring 23 and the valve body 2 toward the cavity B side. However, the fluid flow velocity at this time is reduced by the action of the notch 25. In other words, due to the presence of this notch 25, the fluid having the pressure P1 in the upstream fluid flow passage 3 passes through this notch, and then passes through the seat holder 4 defined by the wiper ring 23 and the seat 14. Since it passes through the gap between the valve body 2 and wraps around between the blowdown side of the wiper ring 23 and the seat 14, the pressure between the wiper ring 23 and the seat becomes close to Pl, and the peripheral surface of the wiper ring 24 and the valve body 2 Fluid flow passing therethrough is slowed down. Therefore, there is no large pressure difference between the front pressure of the wiper ring 24 and the back pressure of the pressure P1 applied to the rear surface 23a of the wiper ring 23, so that the wiper ring 23 is prevented from popping out.

Furthermore, if the sheet 14 is damaged for some reason,
Sealant grease is supplied from the coupler 21 to the annular groove 17 through the sealant grease supply hole 22.20. At this time, the supplied sealant grease is sealed between the seal 14 and the wiper ring 23, so that the sealant grease is The sealing performance is maintained for a long period of time, and the sealant grease is prevented from dripping into the fluid flow path 3.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part of a conventional ball valve, FIGS. 2 to 4 show an embodiment of the present invention, FIG. 2 is a cross-sectional view of a main part of a ball valve, and FIG. FIG. 2 is a partial front view of a seat retainer having a wiper ring as seen in the direction of arrow R, and FIG. 4 is a vertical cross-sectional view of a main part of the ball valve shown in FIG. 2. DESCRIPTION OF SYMBOLS 1... Housing, 2... Valve body, 3... Fluid flow path, 4... Seat retainer, 14... Seal, 18
... Annular groove for wiper ring, 23 ... Wiper ring, 25 ... Notch.

Claims (1)

[Claims] 1) The annular seat retainer has two annular grooves, large and small, on the front surface facing the valve body, and the annular seat that slides in contact with the valve body is placed in the large diameter annular groove, and the small diameter annular groove A valve comprising a wiper ring that is in sliding contact with a valve body, characterized in that a part of the upper part of the wiper ring is cut out discontinuously.