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     ProTips

Failsafe Actuators
  • Valworx offers air and electric actuators that can be operated in "fail safe" mode.
  • A "Fail Safe" actuator returns to a "safe" position upon loss of air supply or electrical power.
  • A better understanding of the differences between air and electric failsafe actuation will help you decide the best type for your application.
Electric Actuated Valves with Accessory BSR Installed
5610/5615/5616 Series Valworx actuators can be equipped with pre-installed BSR (Battery Spring Return) system.
 
BSR kits can be pre-set to Fail Open or Fail Closed. This choice denotes the final position of the valve ball or disc after a power failure.
  • 2-Way Ball or Butterfly Valves are the most commonly used with battery backups, the main purpose being to either flush a line out in case of power failure, or to close the valve to prevent continued flow during an emergency.
  • 3-Way Ball Valves will fail to Position 1.  For example, a valve shipped with flow path T2 is normally "open" in Position 2.  It will fail to position 1 per below:




 
For actuators with an optional positioner system installed (which converts Open/Closed valve actuators to throttling actuators), upon resumption of power after an outage, the actuator will return to the position previously held by the control signal.  If the 4-20mA or 0-10v control signal is also lost, the actuator will fail to a pre-determined position of Standard CLOSED, or Optional OPEN.
 
IMPORTANT: Think of the battery only as an emergency backup.  It is not meant to replace the functionality of a switch or relay, which is required to rotate the actuated valve between the two possible 90° positions.
 
Air Actuated Valves with Mechanical Spring Return
Spring Return air actuators can be pre-set to fail open or closed without the purchase of additional accessories.
The following diagram shows normal operation as shipped.
Pneumatic actuated valves can be pre-set at the factory to operate in reverse, so that the valve opens when pilot air is exhausted or lost.The actuator will still rotate counter-clockwise (Reverse Acting).
Shop for Spring Return Air Actuators
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