A flanged pneumatic ball valve is a type of ball valve connected to pipelines via flanges and driven by compressed air. It is mainly used for rapid on-off control of pipeline media and is widely applied in industrial scenarios with high automation levels. Below is an introduction to its core information:
-
Valve Body and Flanges:
The valve body is often made of carbon steel, stainless steel (304, 316, etc.), or fluorine-lined materials. Flanges at both ends are connected to pipeline flanges via bolts, ensuring stable installation and good sealing performance. The applicable pressure rating is typically PN16~PN64, with some high-pressure models reaching PN100 or above.
-
Ball and Sealing:
The internal ball has a circular through-hole, and on-off control is achieved by rotating the ball 90°. Sealing methods are divided into:
- Soft sealing: Using materials such as PTFE or EPDM, suitable for low-pressure, normal-temperature, and clean media.
- Hard sealing: Adopting metal-to-metal contact, resistant to high temperatures, high pressures, and particle erosion.
-
Pneumatic Actuator:
Usually dual-action or single-action (spring-return) type, composed of a cylinder, piston, and rack-and-pinion mechanism. It drives the ball to rotate via compressed air (generally 0.4~0.6MPa). Equipped with a solenoid valve for remote control, some models include a limit switch to feedback the valve’s status.
-
Dual-action Actuator:
Alternating air intake on both sides of the cylinder pushes the piston, driving the rack-and-pinion to rotate, thus achieving 90° rotation of the ball (opening/closing). It has no spring return function, and the valve remains in its current state when air supply is cut off.
-
Single-action Actuator:
Air intake on one side drives the valve to open (or close), while the other side relies on spring force for reset. When air supply is cut off, the valve automatically returns to a preset safe position (e.g., fully closed or fully open), enhancing system safety.
- Rapid Response: Short full open/close time (usually 1~5 seconds), suitable for working conditions requiring quick switching, such as emergency shut-off scenarios.
- Explosion-proof Safety: Pneumatic drive requires no electricity, making it suitable for flammable and explosive environments (e.g., chemical and oil-gas fields). Combined with an explosion-proof solenoid valve, it meets explosion-proof requirements.
- Easy Maintenance: With a relatively simple structure, the actuator has a low failure rate. Flanged connections facilitate disassembly and maintenance, and internal components are easy to replace.
- Strong Adaptability: By selecting different materials and sealing types, it can adapt to water, steam, corrosive media, and fluids containing a small amount of particles.
- Chemical Industry: Control of feed/discharge for reaction kettles, on-off switching of solvent transportation pipelines.
- Oil and Gas Processing: Emergency shut-off of oil tank area pipelines, process switching in natural gas transportation.
- Water Treatment: Control of chemical dosing pipelines in sewage treatment plants, drainage valves for sedimentation tanks.
When selecting a model, the valve body material, actuator type, and sealing form should be determined based on medium parameters (temperature, pressure, corrosiveness), pipeline diameter, control requirements (on-off type/need for emergency reset), and air supply conditions.
