The Top-Mounted Handwheel Piston Linear Pneumatic Actuator is an integrated valve actuation solution that combines a piston-type linear pneumatic actuator with a top-mounted manual handwheel override. It retains fully automatic pneumatic control while providing manual operation for local intervention, maintenance, and emergency situations. This versatile actuator is designed for linear-stroke valves requiring both automated control and reliable manual override.
Working Principle of Top-Mounted Handwheel Piston Linear Pneumatic Actuator
The top-mounted handwheel piston linear pneumatic actuator combines pneumatic actuation with a manual handwheel override, providing both automatic valve control and reliable manual operation. The two drive systems operate independently, allowing quick switching between normal pneumatic operation and manual emergency or maintenance operation.
Automatic Pneumatic Operation：During normal operation, the handwheel mechanism remains disengaged and does not interfere with pneumatic actuation. Clean, regulated compressed air is distributed through a solenoid valve or valve positioner to the actuator chambers, driving the piston and valve stem in a linear motion for valve opening, closing, or precise throttling. Double-acting models provide bidirectional pneumatic control, while single-acting models use a return spring for fail-safe operation.
Manual Handwheel Override：In the event of air or power failure, pneumatic component failure, system commissioning, or maintenance, the top-mounted handwheel can be engaged for manual valve operation. The screw mechanism converts handwheel rotation into linear thrust, allowing precise full-open, full-close, or intermediate valve positioning. The manual mechanism provides self-locking to prevent unwanted valve movement and can be disengaged once pneumatic power is restored, enabling a quick return to automatic operation without actuator removal or recalibration.
A pneumatic actuator converts the energy of compressed air into mechanical motion, enabling the valve to open, close, or continuously modulate its position for reliable and automated valve control. For pneumatic actuator selection and procurement, please contact our technical team and provide the relevant operating parameters so that we can recommend the most suitable actuator model for your application. （Unit: mm）
| Size | Part No | A | C | D | E | nxF | G | H | J | K | L | M | R | T | Y | V | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 20D | XLX-Z20-D-HWT | 125 | 70 | 265 | 3 | M10*4 | F10 | 120 | 65 | 80 | 30 | 35 | M24*1.5 | 180 | G3/8″ | 300 | |
| 25D | XLX-Z25-D-HWT | 150 | 85 | 325 | 4 | M12*4 | F12 | 140 | 65 | 80 | 30 | 35 | M27*1.5 | 180 | G3/8″ | 300 | |
| 30D | XLX-Z30-D-HWT | 150 | 100 | 375 | 4 | M12*4 | F12 | 145 | 70 | 100 | 35 | 40 | M32*2 | 180 | G3/8″ | 300 | |
| 35D | XLX-Z35-D-HWT | 150、175 | 100 | 430 | 5 | M12*4、M16*4 | F12/F14 | 155 | 70 | 100 | 40 | 45 | M36*2 | 200 | G3/8″ | 450 | |
| 40D | XLX-Z40-D-HWT | 175、210 | 130 | 485 | 5 | M16*4、M20*4 | F14/F16 | 170 | 70 | 100 | 45 | 50 | M42*2 | 200 | G3/8″ | 450 | |
| 45D | XLX-Z45-D-HWT | 210 | 130 | 535 | 5 | M16*4、M20*4 | F14/F16 | 170 | 70 | 100 | 55 | 60 | M52*2 | 250 | G3/8″ | 450 | |
| 50D | XLX-Z50-D-HWT | 300 | 200 | 605 | 5 | M16*8 | F25 | 180 | 75 | 100 | 60 | 65 | M58*2 | 250 | G1/2″ | 600 | |
| 55D | XLX-Z55-D-HWT | 300 | 200 | 655 | 5 | M16*B | F25 | 180 | 70 | 120 | 60 | 65 | M58*2 | 250 | G1/2″ | 600 | |
| 60D | XLX-Z60-D-HWT | 300、350 | 200 | 705 | 5 | M16*8、M20*8 | F25/F30 | 190 | 70 | 120 | 70 | 75 | M68*2 | 250 | G1/2″ | 700 | |
| 45D2 | XLX-Z45-D-HWT2 | 300 | 200 | 535 | 5 | M16*8 | F25 | 230 | 75 | 100 | 55 | 60 | M52*2 | 250 | G1/2″ | 600 | |
| 50D2 | XLX-Z50-D-HWT2 | 350 | 230 | 605 | 5 | M20*B | F30 | 240 | 100 | 60 | 65 | M58*2 | 250 | G1/2″ | 700 | ||
| 55D2 | XLX-Z55-D-HWT2 | 350 | 230 | 655 | 5 | M20*B | F30 | 240 | 120 | 60 | 65 | M58*2 | 250 | G1/2″ | 700 |
Key Features of Top-Mounted Handwheel Piston Linear Pneumatic Actuators
Dual Pneumatic & Manual Operation：Combines automatic pneumatic actuation with a top-mounted manual handwheel override. The two drive systems operate independently, enabling smooth switching between automatic and manual operation without affecting pneumatic response, positioning accuracy, or service life.
Compact Top-Mounted Design：The vertical handwheel design saves valuable side clearance compared with side-mounted overrides, making it ideal for compact valve installations, crowded pipelines, and applications with limited operating space.
Reliable Emergency Manual Override：Provides manual valve operation during air or power failure, pneumatic component malfunction, commissioning, or maintenance. This mechanical backup improves operational safety and ensures reliable valve isolation when automatic control is unavailable.
Precise Adjustment with Self-Locking：The precision screw mechanism provides smooth manual operation and accurate valve positioning from fully open to fully closed. The self-locking design prevents unintended valve movement caused by pressure fluctuations or process forces.
High-Performance Pneumatic Actuation：Retains the high thrust, load capacity, durability, and wide temperature capability of a piston linear pneumatic actuator. Compatible with 0.4–0.7 MPa standard air supply and available in Fail Close (FC), Fail Open (FO), and Fail Lock (FL) configurations. It can be equipped with valve positioners, solenoid valves, and other control accessories for automated valve control.
