Internal sealing specific pressure-regulable fixed-ball ball valve

Abstract

The invention provides an internal sealing specific pressure-regulable fixed-ball ball valve, which comprises a valve body, a bonnet, a ball, a floating valve seat, valve packing and the like, wherein a plurality of sets of short adjusting screw units are mounted on the sidewall of the bonnet and are connected with a round hole plate, plungers, springs and the floating valve seat in a valve cavity, the sealing specific pressure between the ball and the floating valve seat can be regulated by rotating short screw lifters outside the sidewall of the bonnet, a plurality of sets of long adjustingscrew units are mounted on the sidewall of the bonnet as well, and can regulate the sealing specific pressure upon the valve seat packing outside the sidewall of the bonnet, and because of the adoption of the the mechanism, the faults of jam and leakage can be eliminated when the valve is in use. The internal sealing specific pressure-regulable fixed-ball ball valve also comprises an automatic dirt-scraping unit, and thereby having longer operability and sealing property.

Description

technical field [0001] The invention relates to a ball valve, in particular to a fixed ball valve with adjustable internal sealing specific pressure. Background technique [0002] The ball valve is the opening and closing device in the fluid pipeline system. Its working principle is: by means of manual, worm gear transmission, electric, pneumatic and other driving mechanisms, a certain torque is applied to the valve stem and transmitted to the ball with the flow channel, so that the ball is relatively The valve seat rotates 90° to complete the opening and closing of the valve. [0003] The structural form of the fixed ball ball valve is mainly manifested in: the ball is fixed, and does not produce displacement after being pressurized, and the valve seat is floating, and produces displacement after being pressurized. The packing between the valves must have an appropriate sealing specific pressure to ensure the internal sealing of the valve, and at the same time there is no ...

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Problems solved by technology

[0004] Manufacturers and researchers in the valve industry at home and abroad have also done a lot of work for this. The "New Structure of Domestic and Foreign Valves" published by China Standard Press in 1997 and edited by Lu Peiwen - the "high temperature valve" disclosed on pages 84 and 85 of the book , "Top mounted ball valve with insulation jacket", such as Figure 5 , Image 6 As shown, they both belong to fixed ball valves. The internal sealing structure is: the valve seat is loaded from the channels on both sides, and the two sides are sealed with flexible graphite packing. There is a butterfly spring on the shoulder of the valve seat. Adjust the nut to press the butterfly spring to achieve it. The disadvantage of this structure valve is: the valve will jam or leak during use, especially the fixed ball valve used in the pipeline system of high temperature, high pressure and other harsh media. occur

[0006] 2. Due to the wear of the sealing surface, the fatigue and relaxation of the spring, etc., the sealing specific pressure of the sealing surface is not enough to cause leakage

[0007] 3. The packing seal between the floating valve seat and the valve body is the pre-tightening force set before leaving the factory. It is difficult to ensure long-term sealing if it cannot be adjusted after use.

[0008] Due to the above reasons, once the valve is in operation, it cannot be ruled out if there is a fault such as jamming or leakage. The only way is to disassemble, replace, and repair. Once the operation of the entire system is affected, it will bring great economic losses.

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