JPS6238062Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a ceramic ball valve that integrates a valve seat and a socket.

Traditionally, ball valves have often been constructed from stainless steel, brass, or other metals. Made of metal, druv is robust and resistant to mechanical and thermal shock. However, it is not desirable to use metal valves for highly corrosive liquids and gases, such as acids and alkalis.

Therefore, the present inventor devised a valve made of ceramic. The material of the part through which the fluid passes is made of ceramic (Utility Model No. 53-75833,
54−47130). The ball valve body, valve box, socket, and valve seat that come into contact with the fluid are made of ceramic, and these parts are housed in a metal cylinder or flange and are pressurized with bolts and nuts to form a valve. be.

Since ceramics cannot be joined by means such as screwing, adhesion, or welding, they must be covered and fastened using metal members.

In these ceramic ball valves, a valve body was rotatably provided between two sockets, and a valve seat was interposed between the valve body and the socket. The valve seat makes smooth contact with the outer circumferential surface of the ball valve, allowing the ball valve body to rotate smoothly without rattling. If the sliding surfaces between the valve seat and the ball valve body are in perfect contact with each other, there will be almost no leakage from the sliding surfaces when the valve is fully closed.

The fluid in the socket hole on the high pressure side (inlet side) pushes the valve body toward the low pressure side and strongly presses the valve seat against the ball valve body. This is because the fluid entering the gap between the valve seat and the socket exerts pressure on the valve seat toward the ball valve body.

If the opening and closing operations are infrequent and the valve closing time is long, the valve body and valve seat will become firmly stuck together. When this happens, a huge amount of torque is required to open the valve.

Ball valves may be operated manually, but in this case, the operator is forced to perform labor-intensive labor.

An actuator is attached to the ball valve, and it is often operated mechanically using a motor, hydraulic cylinder, or pneumatic cylinder. In such a case, a high-output actuator must be provided that can cover the huge torque required to open the valve. This is uneconomical.

Furthermore, the valve stem is inserted into a notch in the ceramic ball valve body, and the valve body is rotated by rotating the valve stem, but if the frictional resistance between the valve body and the valve seat is large, The shearing force applied to the notch of the valve body is also enormous. There is also a risk that the upper notch of the valve body may be damaged due to repeated use.

In order to prevent the valve seat from strongly sticking to the valve body, it is sufficient to reduce the area of the valve seat perpendicular to the flow direction. This is because the force applied to the valve seat is the product of fluid pressure and area.

However, ceramic is brittle against mechanical shock and thermal shock, and weak against tension, so it is not possible to make the valve seat into a thin ring. A strong shearing force is applied to the valve seat when opening the valve, but
In order to withstand shearing force, a certain thickness or more is required. The area perpendicular to the flow cannot be reduced.

This invention solves these difficulties.

The purpose of this invention is to provide a ceramic ball valve that can greatly reduce the frictional force generated between the seat portion and the ball valve body by integrating the valve seat and socket.

Hereinafter, the configuration, operation, and effects of the present invention will be explained in detail with reference to drawings showing embodiments.

FIG. 1 is a longitudinal sectional front view of a ceramic ball valve according to an embodiment of the present invention, and FIG. 2 is a right side view.

This ball valve is made of ceramic material.
It has a socket 1, a valve box 2, a ball valve body 3, etc.
The socket 1 is a thick circular plate, with an inlet hole 5 and an outlet hole 6 passing through the center. A spherical ball valve body 3 is held between two sockets 1, 1 from the left and right sides.

The valve body 2 is cylindrical and communicates between the two sockets 1,1.

The ends of the inlet hole 5 and the outlet hole 6 inside the sockets 1, 1 form seat surfaces 7, 7, which are part of a ball, and are tightly fitted to the outer peripheral surface of the ball valve body 3. In other words, the socket also serves as a valve seat.

Two stepped circumferential surfaces 8 and 9 are formed on the joint surface between the socket 1 and the valve body 2, and O-rings 10 and 10 are interposed between them.

A valve stem through hole 11 is perpendicularly formed above the valve box 2, and a valve stem 12 is inserted therethrough. A packing 13 is fitted into the circumferential groove between the valve stem 12 and the valve body 2. The male threaded portion 14 above the valve stem 12 has
A packing retaining nut 15 and a locking nut 16 are screwed together to press down the packing 13 with appropriate pressure.

The flange 17 of the valve stem 12 is in contact with the inner circumferential surface of the valve box 2 via the seat packing 18.

The lower end of the valve stem 12 is a rectangular valve body insertion part 19, which is fitted from above into a vertical hole 21 communicating with a valve hole 20 passing horizontally through the center of the valve body 3.

The upper end of the valve stem 12 communicates via a coupling 22 to a handle or actuator (not shown).

A step groove 23 is formed on the outer peripheral surface of the socket 1, into which a metal ring 24 and a flange 25 are fitted from both sides.

The flange 25 has bolt/nut through holes 26.
and connection bolt holes 27 are drilled at several locations. The bolt/nut through hole 26 has rings 24, 24.
A long fastening bolt 28 and a nut 29 are provided for fastening. With the fastening bolts and nuts 28 and 29, the ring 24 strongly presses the socket 1 against the valve body 2, and these members are integrated.

The connection bolt hole 27 is adapted to a flange of a pipe to be connected to the connection bolt hole 27, and a bolt is screwed into the flange and into the bolt hole 27 to connect the pipe.

A metal cylinder 30 is provided inside the two flanges 25, 25 so as to cover the entire valve. The end face of the cylinder 30 has flanges 25, 25.
It rests on the step groove 31 on the inner outer circumferential surface. The outer peripheries of the abutting surfaces of the cylinder 30 and the flange 25 are inclined surfaces 32 and 33, respectively, and a tightening ring 34 having an inclined surface on the inner surface holds these down.
The tightening ring 34 is a two-part ring, and the ear piece 3
At 5 and 35, bolts 36 and nuts 37 are tightened in the circumferential direction. Therefore, the flange 25 and the cylinder 30 are integrated.

Such a fastening configuration is similar to the above-mentioned invention. The present invention does not require any such fastening structure, and the gist of the present invention is that the ceramic socket and valve seat are integrated.

Fluid enters the valve through the inlet hole 5 and is discharged through the valve hole 20 and the outlet hole 6 when the valve is open. When the valve is closed, the blind plate portion of the valve body 3 closes the inlet hole 5 and the outlet hole 6.

Since the valve body 3 and the seat surfaces 7, 7 of the socket 1 are in close contact with each other, fluid cannot leak through the contact surfaces. Fluid is shut off.

Since the valve body 3 and the socket 1 on the inlet hole 5 side are directly seated and there is no valve seat, the pressure in this direction is extremely small. The pressure between the inlet socket and the valve body is solely due to the original mechanical coupling force and is not due to fluid pressure. This is because there is no enlarged diameter part in the inlet hole 5 and there is no valve seat.

Therefore, even if the valve is closed for a long time, the seat surface portion 7 on the inlet side and the ball valve body 3 will not exert strong pressure on each other and become stuck.

Of course, the seat surface portion 7 on the outlet side and the ball valve body 3 exert pressure on each other due to fluid pressure. this is,
The same is true for any ball valve. Reducing the sheet surface pressure on the exit side is not the primary objective of the present invention. However, there are also such side effects.

State it more clearly. When the valve closes, the force applied to the inlet side seat surface and outlet side seat surface due to fluid pressure is (1) When there is a valve seat Inlet side pressure SP Outlet side pressure (S + T) P However, here P is The fluid pressure, S is the area of the valve seat projected in the flow direction, and T is the cross-sectional area of the valve seat through hole, which is often equal to the area of the inlet hole 5.

(2) When there is no valve seat (this invention) Inlet side pressure O Outlet side pressure TP. Since the present invention does not have a valve seat, the seat pressure on the inlet side is extremely low. The part derived from fluid pressure is O.

The sheet surface pressure on the exit side also decreases by the amount of the entrance side pressure.

As a result, according to the present invention, the pressing force between the ball valve body and the seat surface is reduced by 2SP, that is, the product of twice the seat packing area and the pressure.

Therefore, even if the valve remains closed for a long time, the seat surface and the valve body will not stick together and it will be difficult to turn the valve body. In the case of manual operation, less force is required for operation. If you use an actuator, you can use one with a smaller maximum rating, making it cheaper and less likely to break down. Since the shearing force applied to the notch (insertion portion 19) of the valve body is reduced, there is less risk of the valve body being damaged.

This is an extremely useful idea.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of a ceramic ball valve according to an embodiment of the present invention. Figure 2 is its right side view. 1...Socket, 2...Valve box, 3...Valve body, 7
... Seat surface part, 12 ... Valve stem, 24 ... Ring, 25 ... Flange, 30 ... Cylinder, 34 ...
Tightening ring.

Claims (1)

[Scope of utility model registration request] Ceramic ball valve body 3 and ball valve body 3
A valve body 2 made of ceramic that can contain a valve body 2, and a valve stem 12 provided in the valve body 2 and which rotates a ball valve body 3.
, a socket 1 made of ceramic having a seat surface 7 provided on both sides of the valve body 2 and seated against the ball valve body 3; and a stepped groove 2 formed on the outer peripheral surface of each socket 1.
3, a fastening bolt 28 and a nut 29 that connect each ring 24 to integrally combine the socket 1 and the valve box 2, and a metal cylinder 30 that can accommodate each of the above-mentioned members. , are fitted on both sides of the cylinder 30, and the ring 24 and the socket 1
a metal flange 25 that comes into contact with the step groove 23;
A ceramic ball valve characterized by comprising a tightening ring 34 that tightens the abutting portion of the cylinder 30 and the flange 25 to connect them.