JPH0615181Y2 - Ball valve leak prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention is capable of being used in a wide temperature range from high temperature to low temperature, and is a leak preventive for a ball valve which is divided into two parts in a plane parallel to the valve shaft and passing through the valve shaft. Regarding the device.

2. Description of the Related Art Conventionally, a ball valve which is divided into two in a plane parallel to the valve axis and passing through the valve axis is known. As a packing structure for sealing the divided surfaces, there is, for example, Japanese Patent Publication No. 45-4113, and this structure is one in which an O-shaped ring for sealing the gland portion and a valve box packing are integrated and used for manufacturing. Is a synthetic resin integral molding method.

Problems to be Solved by the Invention In the above-described conventional example, the O-shaped ring and the valve box packing are integrally molded, so that they are necessarily molded from the same material. However, the valve shaft is inserted and sealed O
The V-shaped ring must be made of a material with a high elastic force such as rubber and is subject to material restrictions, so it is suitable for high temperature (150 ° C or higher) and low temperature (-50 ° C or lower) fluids expected for ball valves. There was a problem in terms of material in obtaining packing that could be used.

In addition, the valve shaft insertion portion is also required to have wear resistance corresponding to the rotation of the valve shaft, whereas such wear resistance is not particularly required for the valve box packing, and if material selection is not difficult. did not become. Furthermore, there is also a problem that abnormal force is applied to the joint between the O-shaped ring and the valve box packing to deform the packing or reduce the sealing effect.

The object of the present invention is to solve the above problems and to configure the gland packing that seals the valve shaft and the valve box packing that seals the split surface of the valve box by selecting the most suitable materials respectively. An object of the present invention is to provide a ball valve leakage prevention device capable of improving leakage prevention performance by devising the structure of the contact portion.

Means for Solving the Problems In order to achieve the above object, according to the present invention, in a ball valve in which a valve box is divided into two parts in a plane parallel to the valve axis and passing through the valve axis, sealing is performed along the dividing surface of the valve box. A valve box packing is provided, and both ends of the valve box packing are provided with contact portions which are separate members and come into contact with a ring-shaped gland packing provided on a plane orthogonal to the valve shaft. A sheet was cut in a direction parallel to the valve axis and inserted into a gap formed by dividing it into two parts, which was used as a leakage prevention device for a ball valve that was clamped and fixed.

Operation As described above, in the present invention, the split valve box is sealed by closely fitting the split surfaces with the valve box packing and fastening and fixing both. At the same time, the gland packing, which is a separate member, seals the valve shaft with the gland portion. Also, since both ends of the valve box packing are sandwiched by the gap cut into two parts of the gland packing and are in contact with each other in a direction substantially at right angles to the valve shaft, there is a difference in sealability due to different members and mutual By complementing each other, the sealing performance is improved. Further, even when the valve shaft rotates to open and close the valve element, the valve box packing is not integrally molded with the gland packing, so that abnormal stress is not applied to the contact portion.

Examples Hereinafter, the drawings shown as examples will be described. First
In FIG. 2 and FIG. 2, reference numerals 1 and 2 are valve boxes, and the dividing surfaces 3 divided into two are sealed and integrated. 4 is a valve body, 5
Is the valve shaft. Reference numeral 6 is a valve box packing, which is fitted in a groove provided in the dividing surface 3 of the valve boxes 1 and 2 to seal the valve boxes 1 and 2. 7 is a gland packing, which is inserted and fixed between the valve shaft 5 and the valve housings 1 and 2 via a packing retainer 8.

As shown in FIG. 2, the end of the valve box packing 6 is in contact with the gland packing 7, and both are made of different members. In this embodiment, for example, the gland packing is made of fluororesin and the valve box packing is made of expanded graphite.
A metal packing or other material may be used for the valve box packing, and a material having excellent wear resistance and temperature characteristics such as high temperature and low temperature is used.

As shown in FIGS. 2 and 3, the contact portion 9 between the gland packing 7 and the valve box packing 6 is made to contact the valve shaft 5 in a direction substantially at right angles, and
The sheet is cut in a direction parallel to the valve shaft 5, and the cut gap portion is cut.
The end of the valve box packing 6 is inserted into 10 and sandwiched to enhance the adhesion and sealing action of both.

4 and 5 show another embodiment of the contact portion, in which the end portion of the valve box packing 6 is clamped in the gap portion 11 at a position deviated from the center line of the gland packing 7.

Effect of the Invention Since the present invention has the above-mentioned configuration, the valve box packing for sealing the split surface of the valve box divided into two parts and the gland packing of the gland part are appropriately selected and used. It can be molded, is easy to mold, and can be used from high temperatures to low temperatures. Also, the gland packing and the valve box packing are configured separately, and the contact parts of both are made to contact the end of the valve box packing in the direction perpendicular to the valve shaft and to be sandwiched in the gap part of the two divided gland packings. As a result, the sealing effect is improved without fluid leakage. In particular, it is possible to completely prevent leakage due to damage or deformation of the joint portion that occurs when the valve box packing and the gland packing are integrally molded as in the conventional example, and it is possible to provide an excellent ball valve leakage prevention device. .

[Brief description of drawings]

FIG. 1 is a sectional view showing the whole ball valve, FIG. 2 is an enlarged sectional view of a gland portion, FIG. 3 is a plan view of a contact portion between a gland packing and a valve box packing seen from above, and FIG. Similarly, a plan view showing another embodiment of the contact portion and FIG. 5 are sectional views of the same. 1, 2 ...... Valve box, 3 ...... Dividing surface, 5 ...... Valve shaft 6 ...... Valve box packing, 7 ...... Gland packing 9 ...... Contact part, 10, 11 ...... Gap part

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A ball valve in which the valve boxes (1) and (2) are divided into two in a plane parallel to the valve axis (5) and passing through the valve axis, and a valve box packing (6) for sealing along the dividing plane (3) of the valve box is provided At both ends of the valve box packing 6, there are provided contact portions 9 which are separate members and come into contact with a ring-shaped gland packing 7 provided on a plane orthogonal to the valve axis. A gap that is cut in half in the direction parallel to the valve axis
Ball valve leakage prevention device characterized by being inserted into 10 and fixed by tightening.