| • Parts introduction |
| 1. Indicator |
| Position indicator with NAMUR is convenient for mounting accessories such as Limit Switch box, Positioner etc. |
| 2. Pinion |
| The pinon is high-precision and integrative, made from nickelled-alloy steel, full conform to the lastested standards of ISO5211、DIN3337、NAMUR. The dimensions and the stainless steel matericl can be customized . |
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| 3. Actuator Body |
| According to the different requirements, the extruded aluminum alloy ASTM6005 body can treated with hard anodized, powder polyester painted (different colour is available such as blue, orange, yellow etc.), PTFE or Nickel plated. |
| 4. End Caps |
| Die-casting aluminum powder polyester painted in different colours ,PTFE or Nickel plated. |
| 5. Pistons |
| The twin rack pistons are made from Die-casting aluminum treated with hard anodized or made from Cast steel with galvanization. Symmetric mounting position, long cycle life and fast operation, reversing rotation by simply inverting the pistons. |
| 6. Travel Adjustment |
| The two independent external travel stop adjustment bolts can adjust ±5°at both open and close directions easily and precisely. |
| 7. High performance springs |
| Preloaded coating springs are made from the high quality material for resistant to corrosion and longer service life, which can be demounted safely and conveniently to satisfy different requirements of torque by changing quantity of springs. |
| 8. Bearings & Guides |
| Made from low friction, long-life compound material, to avoid the direct contact between metals. The maintenance and replacement are more easy and convenient. |
| 9. O-rings |
Normal:NBR
High temp. & low temp. :Viton or Silicone |
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| • Operating Principle ( Standard Rotation ) |
| 1. Double action (planform) |
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Air into Port A forces the pistons outwards,
causing the pinion to turn counterclockwise
while the air being exhausted from Port B. |
Air into Port B forces the pistons inwards,
causing the pinion to turn clockwise while
the air is being exhausted from Port A. |
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| 2. Single action (planform) |
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Air into Port A forces the pistons outwards, causing
the springs to compress, the pinion turns counterclockwise
while air is being exhausted from Port B. |
In the event of loss air pressure or power, the stored
energy in the springs forces the pistons inwards, causing
the pinion turns clockwise while air is being exhausted from
Port A, and air to Port B can accelerate closing the valve. |
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*Note:
1.The standard rotation is clockwise for closing the valve, while counterclockwise for opening.
2.lf the assembly direction of the piston is reversed,then the standard rolation is counterclockwise for closing the valve,clockwise for opening. |
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| • The function and usage of the actuator and the parts |
•Double action actuator :open and close the valve.
•Single action actuator (Spring return ):when air or power is lost, the actuator either close the valve automatically (normal-closed style ) or opens the valve automatically (normal-open style).
•Double-control solenoid: power to solenoid opens the valve, power to the other solenoid closes the valve. This kind of
solenoid possesses the memorial function (available for anti-exploding).
•Single-control solenoid: power to the solenoid opens or closes the valve. Loss of power will close or open the valve
(available for anti-exploding).
•Limit switch box (signal feedback): remotely passes the signal of the valve's opened and closed status (available for antiexploding).
•Pneumatic positioner: according to the air pressure (0.2-1bar) to control the medium fl ux (available for anti-exploding).
•Electric positioner: according to the electric current (4-20mA) to control the medium fl ux (available for anti-exploding).
•Electric-pneumatic transfers the current signal to air pressure signal for compatibility with positioner .
•Tri-unit Air disposal: this includes decompression, fi lter, and oil unit, can clean and lubricate the connection parts.
•Manual equipment: able to use manual operation in the event of loss of air or power. |
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| • Sizing Information |
Make sure the torque of the opening or closing valve, under normal conditions is set to a safety factor of 15-20%. For water vapor and non-lubricated liquid medium, raise safety factor setting to 25%. For non-lubricated pasty medium, raise safety factor to 40%; For non-lubricated granule powder, raise safety factor to 80% .Then, according to the air pressure; search for the actuator's type in the output torque table of dual action or single action, In the output torque table of single action, the end line of the output torque of the spring is the torque of the closing the valve.
Sizing: dual action actuators |
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Example:
•The torque needed by ball valve=280N.m
•Operating medium :water
•Safety factor(20%)=280N.m+20%=336N.m
•Air supply pressure=4Bar
•According to the output torque table of the dual action actuator, we choose RAT140DA. when the air supply pressure
at 4Bar, its output torque is 350.96N.m |
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