Common Valves for Natural Gas Pipelines-Pipeline Ball Valves
There are various types of valves with a wide range of applications. The valves commonly used in natural gas pipelines mainly include pipeline ball valves, slab gate valves and plug valves. Among them, pipeline ball valves are the most widely used.
The valve body of the pipeline ball valve can be divided into a fully welded valve body design and a split bolted valve body design. The sealing performance of the valve seat is the key technology of the fully welded ball valve, which directly affects the sealing performance and service life of the ball valve. In order to ensure the reliability of its sealing performance, the following measures are usually taken in the structural design: double-piston effect double-sealing valve seat structure, self-releasing single-sealed valve seat structure.
The sealing of the valve body of the pipeline ball valve usually adopts combined sealing and the commonly used methods mainly include the following three:
1. Primary metal seal and secondary soft seal
2. Primary metal seal, secondary nylon or PTFE, seals made from other materials and tertiary rubber soft seal.
3. Unique seat triple sealing structure: To make the valve seal more effectively, the structure adopts triple sealing structure.
The pipeline valve needs to have fire safety function, so its structure must be fireproof. At present, the commonly used method is to add graphite seals to the valve stem and valve seat support ring. The graphite seal has good high-temperature resistance, which can effectively reduce the leakage of the medium in the event of a fire, and has a good fire prevention effect.
The valve body of the pipeline ball valve can be divided into a fully welded valve body design and a split bolted valve body design. The sealing performance of the valve seat is the key technology of the fully welded ball valve, which directly affects the sealing performance and service life of the ball valve. In order to ensure the reliability of its sealing performance, the following measures are usually taken in the structural design: double-piston effect double-sealing valve seat structure, self-releasing single-sealed valve seat structure.
The sealing of the valve body of the pipeline ball valve usually adopts combined sealing and the commonly used methods mainly include the following three:
1. Primary metal seal and secondary soft seal
2. Primary metal seal, secondary nylon or PTFE, seals made from other materials and tertiary rubber soft seal.
3. Unique seat triple sealing structure: To make the valve seal more effectively, the structure adopts triple sealing structure.
The pipeline valve needs to have fire safety function, so its structure must be fireproof. At present, the commonly used method is to add graphite seals to the valve stem and valve seat support ring. The graphite seal has good high-temperature resistance, which can effectively reduce the leakage of the medium in the event of a fire, and has a good fire prevention effect.
