Pneumatic Actuator Control Globe Valve

Pneumatic control globe valve also known as pneumatic cut-off valve, is a kind of actuator in the automation system, consisting of multi-spring pneumatic film actuator or floating piston actuator and regulating valve, receiving the signal of regulating instrument, controlling the cutting off, connecting or switching of the fluid in the process pipeline. It has the characteristics of simple structure, sensitive response and reliable action. It can be widely used in petroleum, chemical industry, metallurgy and other industrial production sectors. The air source of the pneumatic cut-off valve requires filtered compressed air, and the medium flowing through the valve body should be free of impurities and particles of liquid and gas.
The cylinder of the pneumatic globe valve is a stereotyped product, which can be divided into single action and double action according to the mode of action. The single-acting product has a reset cylinder spring, which has the automatic reset function of losing air, that is, when the cylinder piston (or diaphragm) is under the action of the spring, the cylinder push rod is driven back to the initial position of the cylinder (the original position of the stroke). The double-acting cylinder has no return spring, and the advance and retreat of the push rod must depend on the inlet and outlet position of the cylinder air source. When the air source enters the upper chamber of the piston, the push rod moves downward. When the air source enters through the lower cavity of the piston, the push rod moves upward. Because there is no reset spring, the double-acting cylinder has more thrust than the same-diameter single-acting cylinder, but it does not have the automatic reset function. Obviously, different intake positions make the putter move in different directions. When the air intake position is in the back cavity of the push rod, the air intake makes the push rod advance, this way is called the positive cylinder. On the contrary, when the air intake position is on the same side of the push rod, the air intake makes the push rod back, which is called the reaction cylinder. Pneumatic globe valve because the general need to lose air protection function, usually use a single acting cylinder.