ZSA Pneumatic Piston Linear‑stroke Actuator
ZSA‑series actuators are available in two types: single‑acting and double‑acting. The single‑acting type adopts multi‑spring design. Since its air supply pressure is higher than that of diaphragm actuators, it delivers larger output force. It is generally applied for control valves and shut‑off valves working under high pressure or large pressure differential.
Technical Parameters and Performance
Model: Direct‑acting: ZSA17D ZSA25D ZSA32D ZSA40D ZSA50D
Reverse‑acting: ZSA17R ZSA25R ZSA32R ZSA40R ZSA50R
Double‑acting: ZSA17 ZSA25 ZSA32 ZSA40 ZSA50
Action: Direct‑acting (D): Output shaft descends as air pressure increases
Reverse‑acting (R): Output shaft ascends as air pressure increases
Double‑acting: Output shaft can ascend or descend with increased air pressure
Air supply pressure: 400KPaG, 500KPaG
Materials: Cylinder: Aluminum alloy
Piston: Aluminum alloy
Bracket: Carbon steel
Push rod: 45# steel with hard chrome plating
Ambient temperature: Standard type ‑30~+70℃
Surface coating: Gray
Air supply port: HA22‑45: M16×1.5; HA56: Rc1/2
Accessories: Positioner, air filter‑regulator, booster, pneumatic control valve, lock‑up valve, solenoid valve, limit switch, handwheel mechanism, etc.
Performance:
Remarks: The performance of the actuator without positioner may vary depending on the packing used.
Structure
Figure 1‑1 Double‑acting Type
When compressed air enters through port (B), the piston together with the push rod moves upward and air exhausts from port (A). The push rod connected to the valve stem moves upward to open the valve. Conversely, when compressed air enters through port (A), the piston together with the push rod moves downward and air exhausts from port (B), so as to close the valve.
Figure 1‑2 Single‑acting Type
Reverse‑acting: When compressed air enters through port (B), the piston together with the push rod compresses the spring and moves upward, with air exhausted from port (A). The push rod connected to the valve stem moves upward to open the valve. On the contrary, the spring resets, gas inside the cylinder exhausts from port (B), driving the piston and push rod downward to close the valve.
Direct‑acting: Operating steps are opposite to reverse‑acting type.
