Diaphragm type pneumatic actuator

I Structure and Principle

PM series diaphragm pneumatic actuators have two types of action: positive and negative. When the signal pressure increases, the push rod extends out of the membrane chamber, which is called positive action. When the signal pressure increases, push rod back into the membrane chamber is call edreaction, with the valve to form an open air. Its principle: when the signal pressure is input into the membrane chamber, the thrust is generated on the diaphragm and the spring is compressed to cause the spring to move, drive the valve stem and change the flow area between the valve core and the valve seat until the counter force of the spring and the thrust acting on the diaphragm by the signal pressure are balanced, so as to achieve the purpose of automatic adjustment of technological parameters.

II Specifications and technical parameters

Note: The data in the table are standard configuration of our company, and can be selected separately according to user's requirements. Thrust force is calculated at 0.4MPa.

III Main performance indicators and parameters

1.Main performanceindicators

Note: The performance index of this product is GB/T4213-92

2. Main parameters

Note :(1) the allow able pressure difference in this table is calculated according to 40~200Kpa standard.

(2) The pressure difference allowed in this table is calculated according to the fully closed position (P2=0) flow open state of the valve, and the seat compression force is0.05AE.

(3) The data bits in the table are standard configuration of our company, which can be selected separately according to user requirements.

IV. Main parts and materials

Note :(1) the above materials are commonly used in our company, and other materials are available for special requirements;

(2) The specific material brand no. 1 order contract shall prevail.

Control valve accessory:

Manual operation:

Before manual operation, cut off the air source, open the balance small ball valve (inlet of the cylinder), and lift the locating pin on the handwheel;Then unplug the pin on the pin shaft, pull out the pin shaft and turn the handwheel so that the pin hole of the connecting sleeve is aligned with the pinhole of the connecting rod. Turn clockwise, stem down to close the valve; Turn counter clockwise and the valve stem upward to open the valve. After the operation, lower the locating pin on the handwheel to lock the valve position.

Main functions of accessories:

(1) Valve positioner: Improves the position accuracy of the valve, and can realize the function of interval control, positive and reaction.

(2) Electro pneumatic valve positioner; Through the electric-gas conversion,the operation can accept the current signal of the electric instrument.

(3) Handwheel mechanism: When the regulating system fails or the air sourceis insufficient, manual operation can be carried out without affect ingproduction.

(4) Air filter pressure reducer: it receives the air pressure from air compressor. After filter purification, pressure regulating and pressure stabilizing, input valve positioner

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