The difference in the use of soft sealing ball valve and hard sealing ball valve-soft sealing ball valve, hard sealing ball valve

The hard seal of the ball valve is the seal between metal and metal, and the sealing ball and valve seat are both metal. Reference material: The machining accuracy and process are difficult, and it is generally used in high pressure, usually above 35MPa. Soft seal is the seal between metal and non-metal, such as nylon \ tetrafluoroethylene, the manufacturing standard is the same. In the manufacturing process of ball valves, due to the complex working environment of many chemical and mechanical industries, many of which are high temperature and high pressure, the friction resistance of the medium is large, and the corrosiveness is strong. Now the technology has advanced, the use of various materials is better, processing, etc. It can keep up with all aspects, so that the hard-sealed ball valve has been widely promoted. In fact, the principle of hard seal ball valve is the same as that of soft seal, but because it is a seal between metals, it is necessary to consider the hardness relationship between metals, as well as working conditions, what medium to use, etc. Hardening treatment is generally required, and continuous grinding between the ball and the valve seat is required to achieve sealing. The production cycle of hard-sealed ball valves is long, and the processing is relatively complicated, and it is not easy to make hard-sealed ball valves well. On the ball valve ball valve sealing material Soft and hard seals are for the sealing material of the valve seat, and the hard seal is accurately processed with the valve seat material to ensure the matching accuracy with the valve core (ball), generally stainless steel and copper. Soft seal means that the sealing material embedded on the valve seat is a non-metallic material. Because the soft sealing material has a certain elasticity, the processing accuracy requirements are lower than that of the hard seal. In terms of the use conditions of the ball valve, the soft seal can generally achieve a high seal, while the hard seal can be high or low according to the requirements; the soft seal needs to be fireproof, because at high temperatures, the material of the soft seal will leak, while the hard seal does not have this. Problems; hard seals can generally do very high pressures, but soft seals cannot; soft seals cannot be used in some occasions due to the problem of the flowing medium (such as some corrosive media); the latter hard-sealed valves are generally better than soft-sealed valves. expensive. As for manufacturing, there is little difference between the two, the main difference is the valve seat, the soft seal is non-metallic, and the hard seal is metal. In the selection of equipment, the selection of soft and hard sealing ball valves is mainly based on the process medium, temperature and pressure. Generally, the medium contains solid particles or has wear or the temperature is higher than 200 degrees. It is better to use hard sealing. Considering the torque of opening the valve, a fixed hard-sealed ball valve should be used when the torque is large. The sealing level of both soft and hard seals can reach level 6.