The pneumatic three-way internal thread ball valve produced and sold by Huadian Pump Valve Company is a new type of three-way switching adjustment/shut-off valve developed by integrating advanced technology at home and abroad. The standard ball core has L-shaped three-way dual channel, which changes the relative angle between the ball core and the pipeline, and can realize different combination control of the three pipeline fluids; T-type pneumatic three-way internal thread ball valve can play the role of proportioning, which is suitable for the ratio adjustment and control of liquid, gas, steam and other media. Pneumatic three-way internal thread ball valve is composed of pneumatic piston double-acting or single-acting (spring return) actuator, with proportional adjustment type (using electro-pneumatic valve positioner, powered by electrical signals and compressed air, accepts 0-10mA DC or 4-20mA DC current signal input by the control system, changes the rotation angle of the ball core, and can realize proportional adjustment action). Two-position switching type (using electromagnetic directional valve, valve position echo, AC220V or DC24V power supply voltage and compressed air as power, to achieve rapid switching control of fluid medium).