JPH0332861Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a ball valve used for underground piping, and in particular, a ball valve used for underground piping using plastic pipes, especially polyethylene pipes. It is related to.

[Background of the idea]

Traditionally, pipes, valves, and joints made of metal such as steel have been used for underground piping, but recently, in such underground piping,
Metal corrosion has become a problem. Particularly in gas piping, if a gas leak occurs due to metal corrosion, it poses a danger to life and fire. In order to prevent such metal corrosion, conventional measures have been taken such as coating the surfaces of metal pipes, valves, joints, etc. for corrosion protection. However, if there is no problem in terms of mechanical strength, for example, for piping with a small diameter, polyethylene pipes are increasingly being used as a corrosion prevention measure.

Although there is still room for consideration in terms of cold resistance, weather resistance, etc., piping using polyethylene pipes is extremely superior to conventional piping methods in terms of chemical stability, workability, cost, etc. It is believed that its use will increase in the future. With regard to joints used for such piping using polyethylene pipes, the development of joints made of the same material has progressed, and joints that can be used satisfactorily have already been made.
However, with respect to valves used in such polyethylene pipe piping, no valve that is satisfactory in terms of quality and cost has yet been developed.

The main reasons for this are that although polyethylene has excellent flexibility, ductility, and chemical stability, it cannot be connected by adhesive, so connections must be made by full welding using the fusion method, and it has poor mechanical strength. This is due to a lack of. Traditionally, metal valves have been used for piping with polyethylene pipes, and these have been connected to the polyethylene pipes using special fittings, but this has poor workability and is not economically viable. Not only are they inferior in terms of performance, but there are also safety issues. A valve made entirely of polyethylene was also developed;
In the case of pipes and fittings, it is sufficient to simply prevent the leakage of gas, water, or other fluids flowing inside the pipe, but in the case of valves, it is not only necessary to prevent leakage of fluid, but also to open, close, and adjust the flow of fluid. Therefore, the mechanical strength, especially the rigidity, of polyethylene becomes a problem. In other words, when operating a valve, the valve seat and ball valve element, which are built inside to seal the valve, slide to open and close the valve, and for this purpose, torque is applied to the ball valve element. When mechanical deformation occurs in the valve body, ball valve, etc. due to external temperature changes, external stress due to operation, loads caused by burying, etc., the sealing surface pressure between the valve seat and ball valve changes and the seal is damaged. The ball valve may deteriorate and cause leakage, or the force required to rotate the ball valve increases, and in extreme cases, the valve may become impossible to operate, and forcing the valve may cause damage. becomes.

[Purpose of invention]

The object of the present invention is to be used for piping made of polyethylene or other plastic pipes as described above, to be able to be easily and completely connected to such piping by full welding using the fusion method, and to be able to use special joints. To provide a ball valve for underground plastic pipe piping, which can be buried underground without requiring it and without causing any problems regarding mechanical strength, especially rigidity.

[Summary of the idea]

The characteristic feature of the ball valve used for piping using plastic pipes buried underground according to the present invention is that the valve body is composed of at least two split metal body parts, allowing fluid to flow out or flow in. In order to achieve this, an annular shoulder is formed inside the opening formed in the body portion, and a flange portion that is made of a material that can be fused with the underground pipe and that can be tightly attached to the annular shoulder is provided. An integrally formed fluid inflow/outflow pipe portion is inserted into the opening of the body portion from the inside of the body portion, the flange portion thereof is brought into contact with the annular shoulder portion, and a seat ring is disposed inside the flange portion. Then, a metal or plastic ball valve is inserted between the seat rings of these body parts, and then the body parts are assembled and connected to each other using stud bolts or other connecting means to form a valve body. The upper end of the valve stem for rotating the ball valve is projected from the top surface of the valve body, and the side and bottom surfaces of the metal part of the valve body formed as described above are provided with electrically insulating and mechanical properties. The lower end of the sheath pipe, which is buried vertically in the ground, is completely covered with a strong anti-corrosion material and the lower end of the sheath pipe is buried vertically in the ground to pass the operating tool for operating the upper end of the valve stem from the ground. A receiving portion for receiving the above-mentioned corrosion-resistant material is integrally formed on the upper part of the coating of the anti-corrosion material.

[Example of idea]

Hereinafter, embodiments of the ball valve according to the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In the figure, 1 indicates a valve body, which consists of split metal body parts 1A and 1B, which are connected to hexagonal bolts, stud bolts 2, etc. They are connected together by. An opening 3 is formed in each of the body parts 1A, 1B for allowing fluid to flow out or in, and an annular shoulder 4 is formed inside the opening 3.

Polyethylene pipe buried underground (chain line 5)
A fluid inflow/outflow pipe 7 is made of a material that can be fused with the body part 1A or 1B, generally the same polyethylene, and is integrally formed with a flange part 6 that can be tightly attached to the shoulder part 4. Part 3
By inserting the polyethylene fluid inflow/outflow pipe 7 into the metal body parts 1A, 1B by bringing the flange part 6 into contact with the annular shoulder part 4, the polyethylene fluid inflow/outflow pipe 7 is attached to the metal body parts 1A, 1B so as not to slip out.

A seat ring 8 is disposed inside the flange portion 6 of the fluid inflow/outflow pipe 7, and the body portions 1A, 1
A ball valve 9 made of metal or plastic is interposed between the seat ring 8 provided on the seat ring B, and the body parts 1A and 1B are connected to each other by hexagonal bolts, as described above.
They are interconnected by stud bolts 2 or other suitable means to form an integral ball valve. In the figure,
10 is a lid made of vinyl chloride or other insulating material that closes the upper part of the valve body 1 formed as described above, 11 is a valve stem for rotating the ball valve, and its upper end 12 is connected to the lid 10. A receiving portion is formed that projects upward from the center of the top surface of the valve and engages with an operating tool for operating the valve from the ground.

A corrosion-proof coating 13 is provided to completely cover the side and bottom surfaces of the metal portion of the valve body formed as described above. This anti-corrosion coating 13 is made of a material with excellent electrical insulation and mechanical strength, such as resin concrete. Therefore, in order to pass an operating tool for operating the upper end 12 of the valve stem 11 from the ground, a sheath pipe 14 is provided that passes vertically from the ground and reaches the valve, and is coated with the corrosion-resistant coating. A cylindrical portion 15 that receives the lower end of the sheath tube 14 is integrally formed at the upper portion of the sheath tube 13 . Note that an O-ring 16 is provided to prevent underground water, soil, etc. from entering the sheath pipe 14.

The ball valve formed as described above has its fluid inlet/outlet pipe 7 made of polyethylene, so it can be easily welded and connected by the fusion method in polyethylene pipe piping, and can be easily welded to the polyethylene piping. No expensive mechanical joints are required. However, since the valve body part is made of metal, the seal part is not affected by external stress during operation, loads such as soil applied from the outside, or external temperature changes, and the seal surface The pressure is maintained constant and the valve can be operated smoothly at all times. Moreover, the outer surface of the metal part of this valve does not come into direct contact with the soil, so there is no problem of metal corrosion.

FIG. 2 shows another embodiment of the ball valve according to the present invention. This embodiment is in principle the same as that shown in FIG. In addition, a seat ring 17 is integrally formed on the flange portion of the inner end of the fluid inflow/outflow pipe 7. Therefore, in this embodiment, the fluid inflow/outflow pipe and the seat ring can be integrally molded, and can be manufactured at a lower cost than the one shown in FIG.

The above embodiments have all been explained as ball valves used for piping with polyethylene pipes, but if a plastic pipe other than polyethylene is used, the material of the fluid inlet and outlet pipes can be changed accordingly. The invention can be applied to any type of piping.

[Effect of idea]

As can be seen from the above description, the present invention provides a ball valve suitable for use in piping using polyethylene or other plastic pipes buried underground. It can be welded by the welding method and can be easily integrated into pipes without the need for particularly expensive parts, and is free from external stresses.
It is not affected by load, external temperature changes, etc., and can always be operated smoothly.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a ball valve according to the present invention, and FIG. 2 is a partial sectional view showing a modification thereof. 1...Body, 2...Stud bolt, 3...
Opening, 4... Shoulder, 5... Pipe, 6... Flange, 7... Fluid inflow/outflow pipe, 8... Seat ring, 9... Ball valve, 10... Lid, 11... Valve stem , 12... Upper end of valve stem, 13... Corrosion-proof coating, 14... Sheath pipe, 15... Cylindrical portion, 16... O-ring, 17... Seat ring.

Claims (1)

[Scope of utility model registration request] In a ball valve used for piping with plastic pipe buried underground, the valve body is composed of at least two split metal body parts, and a ball valve is formed in the body part to allow fluid to flow out or in. An annular shoulder is formed inside the opening, the fluid inflow and outflow pipe is made of a material that can be fused with the underground pipe, and has a flange integrally formed with the annular shoulder. The seat rings of these body parts are inserted into the opening of the body part from the inside of the body part to bring the flange part into contact with the annular shoulder part, and the seat ring of the body part is placed inside the flange part. After inserting a ball valve in between, combine the body parts,
The body parts are connected to each other by stud bolts or other connecting means to form a valve body, and the upper end of the valve rod for rotating the ball valve is projected from the top surface of the valve body, and the valve body is formed as described above. The side and bottom surfaces of the metal parts of the valve body are completely covered with anti-corrosion material with excellent electrical insulation and mechanical strength, and the upper end of the valve stem is operated from the ground. A ball for underground plastic piping, characterized in that a receiving part for receiving in a sealed state the lower end of a sheath pipe buried vertically in the ground for passage therethrough is integrally formed on the upper part of the coating of the above-mentioned anti-corrosion material. valve.