WO2013078866A1

WO2013078866A1 - Ball valve

Info

Publication number: WO2013078866A1
Application number: PCT/CN2012/078495
Authority: WO
Inventors: Cheng Liu; Weiwei JIANG; Jinhong QIAO; Changdong WANG
Original assignee: Danfoss (Tianjin) Ltd.
Priority date: 2011-11-30
Filing date: 2012-07-11
Publication date: 2013-06-06
Also published as: CN202371201U

Abstract

Disclosed is a ball valve, comprising a valve body (2), a valve seat (7), a ball sealer (3) and a valve stem (5) cooperated with each other. The valve seat (7) is connected with the valve body (2) by a screw pair. The ball sealer (3) is received within the valve body (2) and provided with a flow passage hole (31), and the valve stem (5) is connected with the ball sealer (3), to rotate the ball sealer (3)for opening or closing the flow passage (31) of the ball sealer (3). The ball valve can adjust the sealing capability of the sealing pair in the ball valve.

Description

BALL VALVE

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Chinese Patent Application No.

201120488510.X filed on November 30, 2011 in the State Intellectual Property Office of China, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION 1 . Field of the Invention

The present invention relates to a ball valve, more particularly, to a structure for connecting a valve seat and a valve body of the ball valve.

2. Description of the Related Art

In the prior art, an axial force is provided to the valve seat of the ball valve by a necked structure on an outlet connection pipe, so that a sealing member on the valve seat is in tight contact with a ball sealer, thereby forming a sealing pair.

There is no direct connection between the valve seat and the valve body, so that the valve seat can be axially moved. Typically, there is a spring structure between the valve seat and an end of the connection pipe, thereby enhancing a reliability of the sealing pair. In addition, the connection pipe with a necked end is in a threaded connection with the valve seat. With this structure arrangement, it is impossible to actively adjust sealing capability of the sealing pair. Meanwhile, the thread on red copper tubing between the above connection pipe and the valve seat tends to deform due to force applied to the thread, thereby result in

connection failure.

In view of the above, there is a need to provide a new ball valve, in which the sealing ability of the sealing pair of the ball valve can be adjusted without affecting the force applied to the connection pipe.

SUMMARY OF THE INVENTION

An object of the present invention is to alleviate at least one of the above problems and defects in prior arts.

Accordingly, one object of the present invention is to provide a ball valve capable of adjusting the sealing capability of the sealing pair in the ball valve. Another object of the present invention is to provide a ball valve without affecting the force applied to the connection pipes in the ball valve.

In an embodiment, there is provided a ball valve. The ball valve comprises a valve body, a valve seat, a ball sealer and a valve stem cooperated with each other. The ball sealer is received within the valve body and provided with a flow passage hole, and the valve stem is connected with the ball sealer, to rotate the ball sealer for opening or closing the flow passage hole of the ball sealer. The valve seat is connected with the valve body by a screw pair. In one embodiment, a male thread is provided at one end of the valve seat connected with the valve body, while a female thread is provided at one end of the valve body connected with the valve seat, and the male thread and the female thread are in a threaded connection with each other to form the screw pair. In addition, the ball valve further comprises connection pipes welded with the valve seat and the valve body.

Furthermore, sealing members are respectively located at junctions between the ball sealer and the valve seat and the valve body, for forming sealing pairs with the ball sealer. In particular, the sealing members are seal rings.

Further, the connection pipe connected with the valve seat and the valve seat form a chamber with one end thereof necked.

In addition, one end of the valve stem is inserted into a groove of the ball sealer, while the other end of the valve stem is in threaded connection with a valve cap. Further, the valve seat further is provided with a notch for screwing the screw pair between the valve seat and the valve body.

Further, a through hole is disposed at a central of the ball sealer to serve as the flow passage hole.

In addition, the screw pair of the valve body and the valve seat is provided with an adhesive thereon.

In the present invention, the valve seat and the valve body of the ball valve can be connected by the screw pair or the combination of the screw pair and the adhesive, which can adjust the seal capability of the sealing structure formed by the ball sealer and the seal ring. The outlet connection pipe is in a necked form, which can simplify the installation process of the valve body, and reduce welding seam, thereby decreasing outleakage rate.

BRIEF DESCRIPTION OF THE DRAWINGS

Those and/or other aspect and advantages of the present invention can be apparent and readily understood from the following description of the preferred embodiment, in combination with the accompanying drawings, wherein: Fig.1 schematically shows a sectional view of a ball valve in accordance with an embodiment of the present invention;

Fig. 2 is an exploded view of the ball valve of Fig. 1 ; and

Fig.3 is an enlarged view of the portion indicated by the circle A shown in Fig.1 illustrating the screw pair between the valve body and the valve seat of the ball valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

The technical solution of the present invention will be further explained in detail, by the following embodiments, with reference to Figs. 1 -3. Throughout the

specification, the same or similar reference numerals will indicate the same or similar components. The explanation to the implementing of the present invention with reference to the accompanying drawing is intended to interpret the general inventive concept of the present invention, instead of limiting the present invention.

A ball valve in accordance with an embodiment of the present invention is now explained with referring to the accompanying drawings.

As shown in Figs. 1 and 2, they show a schematic sectional view and an exploded view of the ball valve 10 of the present invention. The ball valve 10 of the present invention can be used in a liquid pipe, a gas suction pipe and a hot gas pipe of refrigeration, freezing and air conditioning devices.

Specifically, the ball valve 10 includes a valve body 2; a valve seat 7 connected with the valve body 2 by a screw pair; a ball sealer 3 received in the valve body 2 and provided with a flow passage hole 31 ; and a valve stem 5 connected to the ball sealer 3, to rotate the ball sealer 3 to open or close the flow passage hole 31 of the ball sealer 3. In particular, with referring to Fig. 3, it shows an enlarged view of the screw pair 6 at a junction between the valve body 2 and the valve seat 7 of the ball valve 10 of Fig. 1 . In one embodiment, a male thread is provided at one end of the valve seat 7 connected with the valve body 2, while a female thread is provided at one end of the valve body 2 connected with the valve seat 7. The male thread and the female thread are in a threaded connection, i.e., to form the screw pair 6. It is possible to control and adjust the axial sealing force of the ball valve 10 by adjusting the screw pair 6. In other words, it is feasible to regulate the sealing ability of the ball sealer 3 in the ball valve 10 by adjusting the screw pair 6.

Of course, in accordance with a need for passing fluid through the ball valve 10, the ball valve 10 further includes connection pipes 1 , 8 welded to the valve seat 7 and the valve body 2, respectively. Apparently, the connection pipes 1 , 8 can be connected to the valve seat 7 and the valve body 2 by other suitable means, such as threaded connection or adhesive connection. As an example, the connection pipe 8 connected to the valve seat 7 is subjected to necking process, and the connection pipe 8 together with the valve seat 7 can form a chamber with one end necked.

In particular, as shown in Fig. 2, the ball sealer 3 has a smooth surface and is of abrasive resistance. A through hole is disposed at an axis or a center of the ball sealer 3, serving as the flow passage hole 31 . The surface of the ball sealer 3 is tightly engaged with the valve body 2 and the valve seat 7, so as to form sealing pairs. As an example, the surface of the ball sealer 3 is in tight contact with corresponding sealing members 33 of the valve body 2 and the valve seat 7 (as described in detail later), thereby finally forming as the sealing pairs.

As can be seen from Fig. 2, the sealing member 33 is specifically a seal ring, which is typically in a substantial "O" shape. One end of the valve stem 5 is inserted into a groove 32 of the ball sealer 3, while the other end of the valve stem 5 is in threaded connection with a valve cap 4. The valve stem 5 is generally cylindrical. When the ball valve 10 operates, the valve cap 4 can be rotated along a direction indicated by an arrow B and a torque can be transmitted to the ball sealer 3 by the valve stem 5, thereby controlling the ball valve 10 to be opened; and vice versa. That is, the valve cap 4 can be rotated along a direction opposite to that indicated by the arrow B and accordingly the torque can be transmitted to the ball sealer 3, thereby controlling the ball vale 10 to be closed.

The valve cap 4 is cylindrical and a female thread is provided at an inner wall thereof. The female thread can be cooperated with the male thread at the other end of the valve stem 5, to function as a seal.

In addition, the valve seat 7 may be provided with a notch (not shown) to facilitate screwing and adjustment of the valve seat 7 by a corresponding tool. It should be understood that tightening or releasing of the screw pair 6 between the valve seat 7 and the valve body 2 can be achieved by any other suitable means or any other suitable tools.

As compared with conventional ball valve in the prior art, the valve seat 7 and the valve body 2 of the ball valve 10 in accordance with the present invention, can be connected by the screw pair 6, which can adjust the seal capability of the sealing structure formed by the ball sealer 3 and the seal ring 33. The outlet connection pipe 8 is in a necked form, which can simplify the installation process of the valve body 2, and reduce the welding seam, thereby decreasing outleakage rate.

The operational principle and manner of the ball valve 10 of the present invention are explained now, in combination with Figs. 1 -3. Upon applying a torque to the valve stem 5 by an external force, the torque can be transmitted to the ball sealer 3 by the valve stem 5. When the flow passage hole 31 of the ball sealer 3 is coaxial or completely aligned with the through holes of the connection pipes 1 , 8, the valve body 2, and the valve seat 7, the ball valve 10 is in a completely open state. As such, when the flow passage hole 31 is partially aligned with the above described through holes, the ball valve 10 is partially opened. Of course, it should be understood that when the flow passage hole 31 is perpendicular to or completely misaligned with those through holes, the ball valve 10 is in a completely close state. When the ball valve 10 is in the completely close state, the sealing pair 6 can prevent fluid from inwardly flowing therein.

With the valve seat 7 provided with the notch or other structures, the axial sealing force of the ball valve 10 can be increased or decreased by screwing the valve seat 7, in order to adjust and obtain the desired sealing capability.

In accordance with a second embodiment of the present invention, on basis of the ball valve 10 of the first embodiment, an adhesive may be applied to the screw pair 6 at the junction between the valve seat 7 and the valve body 2. This can increase the axial strength, and thus prevent bad seal resulting from the release of the screw pair 6. The one skilled in the art should appreciate that the adhesive is generally glue, which needs to resist various commonly used refrigerant and oils in the system. Since the ball valve of the second embodiment has similar operational principle with the ball valve 10 of the first embodiment, the detailed description to the operational principle of ball valve in the second embodiment is omitted for sake of conciseness. Although some embodiments of the general inventive concept are illustrated and explained, it would be appreciated by those skilled in the art that modifications and variations may be made in these embodiments without departing from the principles and spirit of the general inventive concept of the disclosure, the scope of which is defined in the claims and equivalents thereof.

Claims

What the claims is:

1 . A ball valve, comprising a valve body, a valve seat, a ball sealer and a valve stem cooperated with each other, wherein the ball sealer is received within the valve body and provided with a flow passage hole, the valve stem is connected with the ball sealer, to rotate the ball sealer for opening or closing the flow passage hole of the ball sealer, characterized in that:

the valve seat is connected with the valve body by a screw pair.

2. The ball valve of claim 1 , characterized in that,

a male thread is provided at one end of the valve seat connected with the valve body, while a female thread is provided at one end of the valve body connected with the valve seat, and the male thread and the female thread are in a threaded connection with each other to form the screw pair.

3. The ball valve of claim 1 , characterized in that,

further comprising connection pipes welded with the valve seat and the valve body.

4. The ball valve of claim 1 , characterized in that,

sealing members are respectively located at junctions between the ball sealer and the valve seat and the valve body, for forming sealing pairs with the ball sealer.

5. The ball valve of claim 4, characterized in that,

the sealing members are seal rings.

6. The ball valve of any one of claims 1 -4, characterized in that, the connection pipe connected with the valve seat and the valve seat form a chamber with one end thereof necked.

7. The ball valve of any one of claims 1 -4, characterized in that, one end of the valve stem is inserted into a groove of the ball sealer, while the other end of the valve stem is in threaded connection with a valve cap.

8. The ball valve of any one of claims 1 -4, characterized in that, the valve seat is further provided with a notch for screwing the screw pair between the valve seat and the valve body.

9. The ball valve of any one of claims 1 -4, characterized in that, a through hole is disposed at a central of the ball sealer to serve as the flow passage hole.

10. The ball valve of any one of claims 1 -4, characterized in that, the screw pair of the valve body and the valve seat is provided with an adhesive thereon.