Multi Turn Actuators
Multi-turn actuators for on-off duty D
The design principle of multi-turn actuators is to turn a multiple of 360 degree at its output-drive.
sketch: Multi-turn actuator
Multi-turn actuators are fitted mainly to valves, which transform the rotation of the actuator's output drive via a threaded bush into a linear movement, which is typically for gate valves and globe valves. Multi-turn actuators for on-off duty (short time operation S2-10/15 min.) mostly operate valves with only a few open-close-cycles per month.
Flanges and output-drives of the multi-turn actuators are standardized by DIN ISO 5210 or DIN 3210 respectively and therefore fit to any modern valve design. Special output flanges for DREHMO actuators are available on request.
DREHMO multi-turn actuators are destinguished according to their rated torque into four housing sizes:
- up to 60 Nm: D... 30, 59
- 60 Nm to 250 Nm: D... 60, 120, 249
- 250 Nm to 1000 Nm: D... 250, 500, 1000
- 1000 Nm to 2000 Nm: D... 2000
Torque values exceeding 2000 Nm are realized by additional gears (spur, or bevel gearboxes) for valve operation.
Multi-turn actuators for modulating duty DR
The demands of modulating service upon actuators and valves are completely different to those "normal", on-off duty. Important demands of modulating service upon actuators are:
Application of DREHMO-Matic C actuators at boiler house of a district heating plant
- high cycling
- enhanced life time of all mechanical and electrical components
- less heating of the motor during operation
- ess backlash of gearing
- minimized time delays during reversing operation
- minimized dead band
DREHMO-Standard actuators for modulating duty are designed for the duty S4. S4 duty means: Intermittent service with consideration of the increase of the motor temperature during starting period. Duty times (ED) of 35% and cycling rates up to 1200 per hour at ambient temperatures up to +60°C could be realized with DREHMO DM C R actuators (see technical data of actuators for modulating duty).
The basis of any DREHMO actuator for modulating duty is the multi-turn type out of the range D 30...DR 1000. Long life time, minimal gearing backlash and delay time are the results of the solid gearing design.
