The Pneumatic Diaphragm Actuator with Side-Mounted Handwheel is a linear spring-return actuator. Equipped with a side-integrated manual mechanism, it supports automatic pneumatic regulation and on-site manual emergency operation, and is applicable to all types of linear-stroke control valves.
Pneumatic Diaphragm Actuator with Side-Mounted Handwheel – Working Principle
Normal Operation: When pneumatic control signal is applied, air pressure pushes the diaphragm to drive the pushrod for linear movement, realizing automatic valve regulation. The manual mechanism remains disengaged and does not interfere with automatic pneumatic operation.
Emergency Operation: In case of air supply failure, signal loss or on-site maintenance, the side handwheel can be operated to drive the pushrod through the internal transmission structure and manually adjust the valve opening on site. Equipped with a travel limiting device, it restricts the maximum valve stroke and prevents valve trim damage caused by over-travel.
Available in direct-acting and reverse-acting versions, the actuator adopts an integrated spring-return design. It automatically resets to the safety position upon air failure to achieve Air-to-Open (FC) and Air-to-Close (FO) fail-safe modes.
Compared with the top-mounted handwheel type, the side-mounted handwheel structure is specially designed for installation sites with dense overhead pipelines and limited top operation space. It provides a comfortable operating angle for convenient on-site operation. Featuring smooth operation and low hysteresis, it supports high-precision continuous modulation when equipped with a valve positioner. It is widely applied in process automation systems of chemical, power generation, water treatment, petrochemical and other industries.
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 | L | H | FC-H1 | FO-H1 | H2 | A | C | D | M | D1 | n-d | E | F | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 22 | XTH22-BOT | 290 | 297 | 90 | 106 | 185 | 250 | 20 | 60 | M8 | 80 | 2-10 | 210 | 250 | |
| 23 | XTH23-BOT | 290 | 326 | 90 | 115 | 185 | 250 | 20 | 60 | M8 | 80 | 2-10 | 210 | 250 | |
| 34 | XTH34-BOT | 365 | 417 | 130 | 170 | 235 | 300 | 22 | 80 | M12X1.25 | 105 | 4-12 | 240 | 300 | |
| 45 | XTH45-BOT | 470 | 525 | 135 | 195 | 322 | 400 | 25 | 95 | M16X1.5 | 118 | 4-14 | 330 | 400 | |
| 56 | XTH56-BOT | 597 | 731 | 170 | 270 | 430 | 500 | 35 | 100 | M20X1.5 | 130 | 4-18 | 375 | 500 |
Pneumatic Diaphragm Actuator with Side-Mounted Handwheel – Key Advantages
Automatic Pneumatic Control + Manual Override：Provides automatic valve regulation during normal operation and reliable local manual operation through the side-mounted handwheel during air supply failure or maintenance.
Ideal for Space-Restricted Installations：The side-mounted handwheel avoids interference from overhead piping, supports and other obstructions, making it ideal for installations with limited overhead operating space.
Adjustable Travel Stop Protection：The integrated travel-stop mechanism limits the maximum valve stroke, preventing over-travel and potential damage to the valve trim.
Smooth & Precise Valve Control：Retains the excellent control characteristics of pneumatic diaphragm actuators, including smooth operation and low hysteresis. With a valve positioner, it provides high-precision continuous proportional control.
Fail-Safe Spring-Return Design：Available in direct-acting and reverse-acting configurations. Upon air supply failure, the actuator automatically returns to its preset safety position, supporting Air-to-Open (ATO) and Air-to-Close (ATC) fail-safe operation.
