JPH0439472A - Ball valve - Google Patents

Abstract

PURPOSE:To obtain a ball valve which does not have trouble such as generation of damage and leakage of fluid and the like when the valve is closed, by contracting the size of a flow path in a ball, by providing a communication part in both end parts of the ball and setting a bore of a small bore side end part of the ball almost equal to the bore of a seat carrier. CONSTITUTION:One end part 4 of large bore and the other end part 5 of bore smaller than that are provided in the inside of a ball 1 to form a flow path 3 with the bore contracted toward the downstream side, and communication holes 6, 7 of connecting the flow path 3 to a valve chamber internal space 8 are provided in the vicinity of the upstream and downstream side end parts 4, 5. Of the flow path provided in a union 12 positioned in the downstream side, a bore of a flow path 10 in a side faced to the ball 1 is formed equal to a bore of a small bore side end part of the ball 1. In this way, propagation of various germs is prevented, when a valve is opened, to eliminate worry about leakage of fluid when the valve is closed, and the situation, such as generating a crack or the like in a valve main unit due to a cause of increasing a pressure of gas from a closed condition, is avoided.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a ball valve suitably used in the semiconductor industry, bio/medical industry, food industry, and other chemical industries (hereinafter referred to as industry). In particular, the present invention relates to a ball valve that does not have a fluid stagnation part when the valve is opened and prevents the generation of germs.

[Conventional technology]

Conventionally, in liquid transportation lines in industry, ball valves have a ball inside the valve chamber and are held between seat carriers equipped with a seat ring, and ball valves have rotatable balls inside a casing with a spherical space inside. Pocketless ball valves, etc., are used, which are arranged so that there are no pockets.

In these conventional ball valves, when the valve is open and liquid is allowed to flow for a long period of time, the space between the valve chamber and the ball and the liquid flow path are completely shut off. The trapped liquid becomes a completely dead liquid (stagnant liquid) and cannot prevent the growth of bacteria.

In addition, since almost the entire surface of the ball in a pocketless ball valve is a sliding part, the rotational torque is large, and in order to do this smoothly, the machining accuracy of the ball and the inner surface of the spherical space must be extremely strict. ,Also,
Microscopically, since it has sliding parts, there are problems such as the inability to prevent the propagation of germs and the like if water enters there.

The present inventor has invented a ball valve that solves the problems of conventional ball valves as described above, and would like to apply for a patent first (Japanese Patent Application No. 1-327372). The ball valve according to the invention has a structure in which an orifice is provided in the flow path of the ball valve, and a communication portion is provided that connects the upstream and downstream sides of the orifice and the valve chamber space.

[Problem to be solved by the invention]

In the ball valve according to the invention of the prior application, when the valve is opened, the fluid that has flowed into the valve chamber space of the valve body always flows out to the outlet flow path, so that no fluid remains in the valve chamber space. It had a structure.

However, if the orifice is provided in the flow path of the ball and the communication portions connecting the valve chamber space are provided on the inlet and outlet sides of the ball flow path before and after the orifice, when the valve is closed, the ball There is a risk that the valve chamber space, the flow path in the ball, and the flow path in the seat carrier such as the union holding the seat will communicate with each other due to the position of the communication part due to slight displacement, resulting in fluid leakage to the downstream side. It cannot be said that there is no sex.

Further, as is common to the conventional ball valve and the ball valve of the prior invention, when the valve is closed, the fluid that has flowed into the valve chamber remains in a sealed state. Such a situation sometimes causes problems; for example, in the semiconductor industry, hydrogen peroxide solution is sometimes flowed into the pipes for the purpose of sterilizing the inside, but if the ball valve is closed after the liquid has flowed,
The hydrogen peroxide solution sealed inside the valve chamber evaporates and the pressure inside the valve chamber increases, causing problems such as cracks in the ball valve body and damage to the seat ring.

The inventor of the present invention took this into consideration to solve both of these problems.The purpose of this invention is to eliminate the risk of fluid leakage at all when the valve is closed, or to eliminate the risk of fluid leakage due to fluid retention when the valve is closed. It is an object of the present invention to provide a ball valve that is improved over the prior invention without causing damage to the valve.

[Means to solve the problem]

As a result of further studies to solve the above-mentioned problems, the inventors of the present invention configured the flow path in the ball so that one end has a large diameter and the other end has a smaller diameter, and furthermore, when the valve is closed, the The present inventors have discovered that the problem can be solved by providing a communication section so that the indoor space, the flow path in the ball, and the flow path in the seat carrier can communicate with each other, and the present invention has been completed.

That is, the configuration of the present invention is described in the first embodiment corresponding to the embodiment.
To explain based on the figure, in a ball valve that opens and closes the valve by rotating a ball 1 provided in the valve chamber,
The flow path 3 provided in the ball 1 has one end 4 of a large diameter and the other end 5 of a smaller diameter, and
Communication portions (communication holes) 6.7 are provided on the large-diameter side and the small-diameter side of the ball 1, respectively, for communicating the internal flow path 3 in the ball with the valve chamber space 8 when the valve is opened. ball 1
The diameter of the flow path 10 on the side facing the ball 1 of the sheet carrier 12 on the small diameter side is made approximately the same as the diameter of the end 5 on the small diameter side of the ball 1.

Further, in a preferred embodiment of the present invention, as shown in FIG. 6, in the above-mentioned ball valve, when the communication portion (communication hole) 6 provided on the large diameter side of the ball 1 is closed, the seat carrier 11 It is characterized in that it is provided so as to communicate with the flow path 9 of.

The flow path of the ball, which is the first feature of the present invention, is provided so that one end has a large diameter and the other end has a smaller diameter, regardless of the upstream or downstream direction. There is. Therefore, it is sufficient that both ends of the flow path have a large diameter and a small diameter, and the intermediate portion connecting the two may have a tapered cross-sectional gantry shape as shown in FIG. As shown in FIG. 3, it may be provided as a combination of a parallel diameter portion with a rectangular cross section and a tapered portion with a loss-shaped cross section, and is not particularly limited.

The second feature is that the communication portions connecting the internal flow paths in the ball provided on the large-diameter side and the small-diameter side of the ball and the valve chamber space may have any shape, such as a groove or a bow, and the number of the communication portions is also limited. Not done. In any case, it may be provided so as not to interfere with the opening/closing function of the ball valve.

In addition, the third feature is that the diameter of the flow path provided in the seat carrier such as the union facing the small diameter side of the ball is
The diameter must be approximately the same as the diameter of the small diameter end of the ball. However, the flow path diameter of the sheet carrier is
It is not necessary to provide them all with the same diameter; only the portion facing the small-diameter end of the ball has the same diameter, and the subsequent flow path is provided with an enlarged diameter as shown in Figure 3. Good too.

The material of the ball valve of the present invention may be metal, plastic, ceramics, etc., and its structure is such that the valve is turned on and off by the rotation of the ball, and the valve is turned on and off by the rotation of the ball. There are no particular limitations on what can be sealed with the seat ring provided on the seat ring.

[For production]

The operation of the ball valve of the present invention having the above structure is shown in FIGS. 1 and 4.
This will be explained based on FIGS.

As shown in FIG. 1, when the ball 1 is rotated to open the valve, fluid flowing from the upstream side flows through the flow path 3 of the ball 1 to the downstream side. On the other hand, since the downstream side of the ball 1 has a small diameter, the small diameter side end 5
In the vicinity, the fluid flow velocity increases. Therefore, due to hydrodynamic action, a tributary branched from this main stream is formed at the ball 1.
It passes through a communication hole 6 provided on the upstream side of the valve chamber, and flows out to the downstream side via the valve chamber interior space 8 and the communication hole 7 also provided on the downstream side. Therefore, in the valve open state, the fluid flowing into the valve chamber space 8 always flows out to the downstream side, so that the fluid does not stay in the space.

When the ball 1 is rotated to close the valve, the state shown in FIG. 4 is achieved. Since the communication holes 6 and 7 provided in the ball 1 are located outside the seat rings 13 and 14, sealing performance is ensured.

Even if the rotating state of the ball 1 is poor and the ball 1 is slightly displaced as shown in FIG. The communication holes 6 and 7 located on the downstream side are located outside the seat ring 14, and even in this state, sealing performance is ensured.

FIG. 6 shows a state in which the communication hole 6 provided on the upstream side of the ball 1 communicates with the flow path 9 of the union 11 when the valve is closed. In this state, even if the gas pressure of the volatile fluid stagnant in the valve chamber space 8 rises, the fluid can flow out to the upstream side through the path indicated by the arrow, and the problem as in the past does not occur. can be avoided. In this case, fluid sealing is ensured by the seat ring 14 on the downstream side, and there is no need to worry about fluid leakage.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an open state of a vinyl chloride resin ball valve of the type in which unions are slidably fitted on both sides of the valve body.

In the figure, reference numeral 1 denotes a ball rotatably mounted in the valve chamber of the cylindrical valve body 2 and supported by a stem 15. Inside the ball 1, one end 4 (hereinafter referred to as the upstream end because it is upstream in this drawing) has a large diameter, and the other end 5 has a large diameter.
(Hereinafter, in this drawing, it will be referred to as the downstream end because it is downstream)
is provided with a smaller diameter than that, and a flow path 3 is formed with a cross-sectional shape that decreases in diameter toward the downstream side, and near the upstream end 4 and the downstream end 5, There are eight communicating holes 6 and 7 each connecting the passage 3 and the valve chamber space 8. (See FIG. 2) The diameter and number of the communication holes 6 and 7 are not particularly limited as long as they are designed taking into consideration the strength of the ball material.

Further, the positions of the communication holes 6 and 7 are not particularly limited, but
Preferably, as shown in FIG.
The seat rings 13, 14 are preferably provided radially outside the seat rings 13, 14 held in the seat ring 13,14.

Note that the valve chamber interior space 8 is surrounded by the cylindrical valve body 2, the ball 3, and the union 11, 12. When the valve opens,
Of course, the fluid flows through the flow path 3 of the ball 1, but some of it flows through the upstream communication hole 6 as shown by the arrow.
The water passes through the valve chamber interior space 8 and further flows in the direction of the flow path 10 of the union 12 via the communication hole 7 on the downstream side. Therefore, in the valve chamber space 8, the fluid is always swept downstream when the valve is open, so that the fluid does not stay there.

The unions 11 and 12 are located on both sides of the ball 1 and are fitted with seat rings 13 and 14. Sealing performance is ensured by bringing the seat rings 13 and 14 into contact with the ball l when the valve is closed. In this embodiment, among the channels provided in the union 12 located on the downstream side, the diameter of the channel 1o on the side facing the ball 1 is formed to be the same as the diameter of the small diameter end of the ball 1. ing.

A handle 16 is attached to the stem 15 supporting the ball 1.
are fitted and fixed.

In addition, 19.20 is screwed onto the outer peripheral side of the cylindrical valve body 2, so that the flanged body cap 17°18 can be adjusted to 0.
- a cap nut which is fixed via a ring to the respective union 11, 12;

FIG. 3 is a longitudinal sectional view showing a second embodiment of the ball valve according to the present invention. This implementation is a modification of Fig. 1.
What differs from the figure is the cross-sectional shape of the flow path 3 provided inside the ball 1. The upstream side has a large diameter and the downstream side has a small diameter, but the middle part is a parallel flow path →
The flow path shape is changed from tapered flow path to parallel flow path.

4 and 5 are cross-sectional plan views of the main parts of the ball valve shown in FIG. 3 in a closed state, centering on the ball. For example, when the state shown in FIG. 4 changes to the state shown in FIG. Even if the condition occurs, the communication hole 6 located on the downstream side is located outside the seat ring 14 of the downstream union 12 and does not communicate with the flow path 10 of the union 12, so fluid leakage does not occur through the seat ring 14 of the union 12. This will be prevented by the ring 14.

FIG. 6 is a cross-sectional plan view of a main part showing a modification of FIG. 4. The difference between this embodiment and the embodiment shown in FIG. 4 is that the communication hole 6 located upstream of the ball 1 opens to the inside of the seat ring 13 attached to the union 11 when the valve is normally closed. It is. That is, it is provided so as to communicate with the valve chamber interior VJ8 and the flow path 9 of the union 11. For example, if the fluid is a volatile fluid, even if the gas pressure of the fluid stagnant in the valve chamber space and ball flow path rises when the valve is closed, the fluid will still flow through the communication hole as shown by the arrow. 6
Since the fluid can flow out to the flow path 9 of the upstream union 11 via the valve body, it is possible to prevent the occurrence of cracks in the valve body due to an increase in fluid pressure in a closed state as in the conventional case. Also, even in this situation, since the diameter of the union 12 on the downstream side is smaller than that on the upstream side, the inner diameter of the IJ song 4 is smaller than that of the seat ring 13, so the downstream side The communication hole 6 located at is located outside the seat ring 14, and sealing performance is maintained on the downstream side. Therefore, even if the valve chamber space 8 and the flow path 9 of the upstream union 11 communicate with each other on the upstream side, there is no problem with fluid leakage from the ball valve itself.

The present inventor manufactured a ball valve having the structure shown in Fig. 3 using transparent acrylic resin, and conducted water mixed with air bubbles under the following conditions to check the flow state of water in the valve chamber space when the valve was opened. did.

(Conditions) 1. Balls... Upstream diameter: 25Φ Downstream diameter: 15Φ 8 pieces of 3Φ both above and downstream of the communication hole 2. Water: Water temperature at 25℃ Water flow rate 0 to 4
0 1/min Water pressure 1.5Kgf / CffI As a result, water containing bubbles passes through the communication hole on the upstream side of the ball, flows through the valve chamber space, and flows into the downstream communication in addition to the main flow that passes through the flow path of the ball. It was clearly confirmed that there was a tributary flowing through the hole into the downstream union channel. That is, it was able to be demonstrated that when the valve is open, the water that has flowed into the space inside the valve chamber is constantly flowing without being stagnant.

〔Effect of the invention〕

As described above, the ball valve of the present invention has the following effects.

(1) When the valve is opened, the flow path inside the ball and the valve chamber space communicate with each other, so that liquid does not remain in the valve chamber space, and the proliferation of various bacteria can be prevented.

(2) When the valve is closed, the communication part provided in the ball moves due to some displacement of the ball, and even if the valve chamber space and the flow path in the seat carrier such as a union communicate, the small diameter flow path Sealing performance can be ensured with the seat ring of the seat carrier, so there is no need to worry about fluid leakage.

(3) When the valve is closed, if the communication section provided on the upstream side of the ball is set to communicate with the upstream sheet carrier〇 flow path, the pressure of gas such as volatile liquid remaining in the valve chamber space will be reduced. Even if it rises, the gas body can flow out to the upstream sheet carrier 〇 flow path side via the communication part of the ball, so the gas pressure rises from the sealed state as in the conventional case. This prevents the occurrence of cracks in the valve body (particularly plastic valves, etc.) due to this.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing an embodiment of the ball valve of the present invention in a fully open state, FIG. 2 is a side view of the upstream side of the ball 1,
FIG. 3 is a longitudinal sectional front view showing a second embodiment which is a modification of FIG. 1, and FIGS. 4 and 5 are transverse planes centered on the ball of the ball valve shown in FIG. 3 in the valve closed state. figure,
FIG. 6 is a cross-sectional plan view centered on the ball, which is a modification of FIG. 4. 1... Bonobe 2... Valve body, 3... Channel, 4... Upstream side part, 5... Downstream side part,
6.7...Communication hole, butt...Valve chamber space, 9
．． 10... Channel, 11.12... Sheet carrier (union), 13.14... Seat ring, 15... Stem, 16... Hand novel 17.18.
...Body cap with flange, 19.20...Cap nut. Fig. 2 1... Hole 4... Upstream end 5... Downstream end 6... Communication hole 13.../-Tring Fig. 4 1 - Hole 3 Flow path 6.7・・Communication hole 8・Valve chamber interior space 5 FIG. 9.10・・Flow path + i, T 2 ・ /− carrier
) + 3. + 4.../-Trinob Fig. 6 1...Ball 3.9...Flow path 8...Valve chamber interior space 11.12...Seat carrier (union) 1j14...Seat ring

Claims (1)

[Claims] 1. In a ball valve that opens and closes the valve by rotating a ball provided in the valve chamber, the flow path provided in the ball has one end with a large diameter and the other end with a large diameter. has a smaller diameter than that, and communication portions are provided on the large diameter side and the small diameter side of the ball, respectively, for communicating the flow path in the ball with the valve chamber space when the valve is opened, and A ball valve, characterized in that the diameter of the flow passage on the side of the seat carrier on the small diameter side of the ball facing the ball is approximately the same as the diameter of the end of the ball on the small diameter side. 2. The ball valve according to claim 1, wherein the communication portion provided on the large diameter side of the ball is formed so as to communicate with the flow path of the seat carrier on the large diameter side when the valve is closed. .