The FM System should not be used for valves requiring automation with multi-turn actuators – the Failsafe System E71 should be used instead.
The Failsafe System E71 should not be used for valves requiring faster activation of the fail-safe mode than the normal motor speed would allow. The FM System should be used instead.
The closing time for the FM System is typically less than 1 second but can be extended if pressure shocks need to be avoided.
The price of the patented FM System is considerably higher than that of the E71.