How to Maintain Ball Valves?

The ball valve is one valve with a ball body as the opening and closing part. With the rapid development of our domestic processing technology, testing technology and intelligent control technology, as well as the emergence of a variety of new sealing materials, the products of ball valves will be more and more widely used. At present, the products of ball valves have been widely used not only in general industrial pipeline, but also in coal to oil engineering, nuclear industry, and aerospace industry pipeline.
 
The basic knowledge of ball valves
 
About the classification of ball valves. The structure and variety of specifications of ball valves, new products and new structures are still emerging. According to the characteristics and use of ball valves, ball valves can be divided into several types. According to the support of the classification, it can be classified into floating ball valves and fixed ball valves. The main characteristics of floating ball valve is without support shaft, ball by the valve inlet and outlet seat to support, valve stem and ball for the movable connection. The valve ball is "floating" between two seats. The valve ball body, the upper and the lower stem of fixed ball valves can be integrated into one whole, or made into an integral shaft ball. The bearing ball can be along the valve channel vertical axis with free rotation, but it can not move along the channel axis. Therefore, the fixed ball valve works. All the forces generated by fluid pressure on the ball are transferred to the bearing. It will not make the valve backseat move, so the valve seat will not bear too much pressure. It is more suitable for high pressure and large diameter occasions. Ball valves can also be classified according to the installation mode, sphere structure classification, and so on.
 
The maintenance skills of ball valves
 
1. Check whether the upstream and downstream pipelines of ball valves have been relieved of pressure before disassembly and decomposition operation. 
2. In order to prevent damage to the sealing surface of parts, especially non-metallic parts, special tools should be used when taking out o-ring.
3. When assembling bolts on the flange, tighten them symmetrically and evenly.
4. Cleaning agents should be compatible with rubber parts, plastic parts, metal parts and working media in ball valves. For instance, when the working medium is gas, usable gasoline cleans metal part and nonmetallic part should be cleaned with pure water or alcohol.
5. The decomposed single parts can be washed by immersion, and the metal parts can be cleaned with clean silk cloth with a cleaning agent. 
6. After cleaning, it is necessary to wait for the wall surface cleaning agent to evaporate before assembling. However, it can not be used for a long time. Otherwise, it will rust and be polluted by dust.
7. The use of grease should be compatible with metal materials of ball valves, rubber parts, plastic parts and working medium. Working medium is gas, such as special grease 221.
8. No metal debris, fiber, grease, dust and other foreign matter are allowed to contaminate or adhere to the surface of parts during assembly.
Finally, open and close the ball valve several times when the installation is completed. If it is flexible and there is no stagnation card phenomenon, it proves that the work is normal. Then, in accordance with the design requirements of the pipeline, inspect the sealing performance with the combination of pipelines and ball valve parts and the flange joint surface. If possible, test the sealing pressure and performance of ball valves according to the standards after piping installation.