MSD-III Diaphragm Actuator
Multi-Spring diaphragm actuator
The MSD-III is a pneumatic diaphragm actuator with a robust rolling diaphragm and multi-spring design. Available in direct acting (DA) and reverse-acting (RA). Fail open and close are achieved by the multi-spring force or compressed air. Additionally, the rugged one-piece cast yoke, pressed diaphragm case and special nylon-reinforced diaphragm provide dependable high force actuation performance. The MSD-III is available in five sizes to cover a wide range of applications. A manual handwheel is an optional extra on both direct-acting (DA) and reverse-acting (RA) actuators as an option.
- Multi-spring design- – Excellent long-term accuracy and fail mode reliability are achieved through the multiple spring design with high compression force.
- Rugged one-piece yoke- – Provides maximum strength and rigidity.
- Diaphragm case- – Pressed steel case provides high mechanical strength and protection in the event of over-pressurisation. Further reinforcements are provided for actuator sizes greater than 290 to ensure safe operation.
- Thrust & stroke capability- – Two actuator types and five sizes allow a wide range of applications.
- Diaphragm- – Moulded elastomer with fabric insert for strength, long life and high sensitivity. The precisely formed diaphragm eliminates any friction and reduces variations in the effective areas during linear operation.
- Various air connection sizes- – Various air connection sizes provide various accessory applications.
- Linearity- – The moulded rolling diaphragm and deep cases minimise area change and provide a linear relation between travel and air pressure.
- Pneumetic multi-spring diaphragm actuator
- DA (Direct Acting – Springs to open)
- RA (Reverse Acting – Springs to close)
- Refer to material table on next page
- -20 °C to 80 °C (optional -40 °C, -55 °C)
- 4.0 kgf/cm² to 5.0 kgf/cm²
- 20mm to 130mm
Optional manual override
- Top handwheel (250, 290, 370)
- Side handwheel (480, 550)
- SIL, TRCU, ATEX