Direct drive valves differ in that the solenoid armature is directly coupled to the valve spool. Thus the valve spool is driven solely by the force generated from the armature itself. As compared to our analog 2-stage valves, direct drive valves are simpler, have no quiescent flow, and are generally smaller. The disadvantage is that direct drive valves have less driving force than 2-stage valves. Less driving force means lower robustness especially in highly contaminated fluid situations. To combat this, FEMA direct drive valves utilize a fine mesh filter on the sleeve ports in order to keep damaging debris out of the metering area. Whereas our 2-stage valves are rated as high as ISO 29/23, FEMA direct drive valves are rated up to ISO 25/20. Since most hydraulic systems operate at or below levels of ISO 19/16, FEMA direct drive valves are more than adequate to exceed performance needs.
Production Direct drive valves include:
- 2,3,4,and 5 way control
- On/off and proportional
- Flow control
- Pressure control
Please contact FEMA to discuss product and system needs further including electronic controller approaches.