Pneumatic ball valve is evolved from globe valve. It has the same 90-degree rotating lift action, except that the cock body is a sphere with a circular through hole or channel passing through its axis. The ratio of the spherical surface to the channel opening should be such that when the ball rotates 90 degrees, spherical surfaces should appear at the inlet and outlet, thereby cutting off the flow. The pneumatic ball valve uses a pneumatic actuator, which only needs to rotate the air source 90 degrees to securely close a small rotational torque. The valve's perfectly equal cavities provide a straight flow path with little resistance to the medium. Pneumatic ball valves are generally considered a good choice for direct opening and closing, but recent developments have designed ball valves to throttle and control flow. The main feature of pneumatic ball valve is compact structure, convenient operation and maintenance, suitable for water, solvent, acid, natural gas and other general operating media and oxygen, hydrogen peroxide and other harsh operations and labor-saving operation, because the ball is supported by the upper and lower bearings, reducing friction and reducing imports Excessive sealing load due to huge sealing load due to pressure propulsion. eliminate. Balls and Seal Sheets.
The pneumatic ball valve has a reliable sealing function. The stainless steel valve seat is embedded with a PTFE single-sex material sealing ring. The end of the metal valve seat ensures that the sealing ring has sufficient pre-tightening force and is equipped with a tension spring. The valve surfaces wear out during use, and the valve continues to ensure a good sealing function during spring operation. Fireproof structure, a fireproof sealing ring is installed between the ball body and the valve seat of the pneumatic fixed ball valve to prevent the PTFE sealing ring from burning due to sudden heat or fire. At this moment, the valve seat sealing ring is rapidly pressed against the sphere under the effect of the spring force, so that a seal is formed between the metals, which has a certain sealing effect. The fire resistance test meets the requirements of AP16FA and API607 specifications. Active pressure relief function, when the pressure of the stagnant medium in the valve cavity rises abnormally and exceeds the pre-tightening force of the spring, the valve seat is retracted from the sphere to complete the effect of active pressure relief, and the valve seat pressure will automatically reset after release. In the drainage pipeline, the upper and lower valve bodies have drainage holes, and check whether the valve seat is leaking. During the operation, if the valve is fully opened or fully closed, the pressure in the core cavity is: it can be directly removed and the packing can be replaced. Drain the preservation fluid into the core cavity to reduce the contamination of the valve by the medium.
Pneumatic fixed ball valve uses auxiliary seat tight sealing system design. If the seal is damaged or fails to seal in an emergency, use an auxiliary sealing system for sealing. The sealing surface can be repaired urgently by injecting the corresponding sealant on the surface. If the conveying medium is dirty or the particle content is low, the sealing surface can also be cleaned by injecting the corresponding detergent or lubricant to protect the sealing surface and ensure a firm seal. Pneumatic fixed ball valves are widely used in the cutting or circulation of pipeline media such as food, medicine, petroleum, chemical industry, natural gas, steel, environmental protection, and papermaking.
