Current Situation and Analysis of Ball Valve Sealing

The cast stone ball valve is an ideal opening and closing device in the ash pipeline, and the quality and service life of the valve are directly affected by the sealing on it. In the past, the O-shaped rubber seal structure was used, that is, the O-shaped sealing ring was placed in the annular groove processed on the shaft, and then assembled into the hole processed on the sleeve parts to form the seal between the shaft and the hole. The sealing performance of the structure depends on the amount of interference in the design, that is, the compression amount of the O-ring and the machining accuracy of the hole and shaft parts. If the interference is too small, the sealing performance will be poor; if the interference is too large, the O-ring will be easily crushed during assembly and the seal will fail.

The sealing structure of the ball valve is simple and easy to assemble. However, if the machining accuracy of the shaft and hole is not high or it is difficult to improve the machining accuracy, in addition to the basic sealing performance is difficult to guarantee or it is difficult to further improve the accuracy, its main disadvantage lies in the sealing material. This sealing structure is still used in cylinders and hydraulic cylinders. Very applicable, it is difficult to guarantee the sealing performance of the cast stone ball valve used in the ash water.

The reason is that the switch of the ball valve is a partial rotary type, often requiring a 90° switch. Due to the dynamic fit between the valve stem and the valve body, there is a certain gap. The huge thrust of the medium acting on the ball when the valve is switched will inevitably make the valve stem tilt to a certain extent. The force of the valve stem is biased to one side, and that side will be severely worn. , and the ash water contains a large amount of suspended matter that erodes the sealing ring. As a result, the life cycle of the O-ring seal at the valve stem is short, and leakage occurs frequently, which also has a certain impact on the site environment. Therefore, it is decided to improve the sealing structure and material. The main starting point after the improvement is to make it fit in the shaft and hole. Among them, it can be adjusted by the amount of compression, and the effective sealing can be guaranteed without greatly improving the machining accuracy of the shaft and the hole.

Xi'an Changxin Metal Products Co., Ltd. can customize the Sanitary Weld Butterfly Ball Valve according to your usage scenarios and needs. Regardless of the product material and its standards, we can meet your needs.

E-mail：sales@cx-hoses-fittings.com