The ball valve is mainly used to cut off or connect the medium in the pipeline, and can also be used for fluid regulation and control. Compared with other valves, the pneumatic O-ring ball valve has the following advantages:
1. The fluid resistance is small, and the ball valve is one of the valves with small fluid resistance. Even the reduced diameter ball valve has relatively small fluid resistance.
2. The thrust bearing reduces the friction torque of the valve stem, which can make the valve stem operate stably and flexibly for a long time.
3. The sealing performance of the valve seat is good. The sealing ring made of elastic materials such as polytetrafluoroethylene is easy to seal, and the sealing capacity of the ball valve increases with the increase of the medium pressure.
4. The valve stem seal is reliable. Because the valve stem only operates as if it is rotating rather than lifting, the packing seal of the valve stem is not easy to be damaged, and the sealing capacity increases with the increase of the pressure of the medium.
5. Due to the good self-lubricating property of materials such as polytetrafluoroethylene and small friction loss with the ball, the service life of the ball valve is long.
6. The lower mounted valve stem and the convex step at the head of the valve stem prevent the valve stem from ejecting. If the valve stem seal is damaged due to fire, metal contact can also be formed between the convex step and the valve body to ensure the valve stem sealing.
7. Anti static function: set a spring between the ball, valve stem and valve body, and the pneumatic O-ring ball valve can lead out the static electricity generated during the switching process.

Introduction to the condition of material selection for compensator
During the application of the compensator, the most concerned thing is the reliability of the compensator. The reliability of the compensator cannot be considered from one aspect alone. Under normal conditions, the reliability of the bellows compensator is composed of multiple links such as planning, manufacturing, installation and operation management. In the pipe network planning, the reliability of the compensator should be considered from these aspects. The first is the selection of materials. In addition to the operating medium, operating temperature and external environment, the possibility of stress corrosion, the impact of water treatment agents and pipeline cleaning agents on materials should also be considered, and the welding The function price ratio of molding and materials selects the economic and applicable bellows manufacturing materials. In general, the following conditions shall be satisfied for the material of compensator:
(1) The excellent plasticity facilitates the processing and forming of bellows, and can obtain satisfactory hardness and strength through subsequent processing technologies (cold work hardening, heat treatment, etc.).
(2) High elastic limit, tensile strength and fatigue strength ensure normal operation of bellows.
(3) Excellent welding compensator can meet the welding technical requirements of bellows in the manufacturing process.
(4) Good corrosion resistance, satisfying the operation requirements of bellows in different environments. Most consumer manufacturers use austenitic stainless steel. In order to improve the corrosion resistance of corrugated pipes, 316 or 316L materials are mostly used for corrugated pipes in the current heat supply network. These two materials are used in the heat supply network, which are about excellent materials in terms of function and price.
1. Use and model
The compensator is connected by an internal pressure compensator and an external pressure compensator.
Usage: Internal pressure balanced corrugated compensator basically solves the thrust problem of blind plate force on fixed support, thus simplifying the design and construction of fixed support and reducing the project cost.
Model: DN100-DN1600, pressure level 0.25Mpa-2.5Mpa/2, operation description
The internal pressure equalizing corrugated compensator can compensate the axial displacement in the pipeline system, and the internal pressure thrust is balanced. This structure can be used in pipelines at high places where fixed supports are not suitable.