How to operate a pneumatic cylinder with a 5/3 way mid position closed valve so that the cylinder remains 40% closed by using 4 - 20mA signals??

 

We have had great success using "Bimba" cylinders with position feedback option. We integrate the cylinder with a digital 4-20 mA positioner for precise positioning in a harsh rugged environment. The positioner can be any brand that accepts 0-10 kOhms feedback. We use PMV D3 Digital positioner for external feedback (linear) and a stainless steel pneumatic cylinder made by Bimba TRD called a LfPf cylinder that has an internal slide wire 0-10 K resistance.The folks at Bimba also make a positioner for their cylinder but we found it not rugged enough and not HART compatible.

 

Check www.processcomponent.se, Universal positioner Quick Stepper for for any type of actuator.

//Staffan Buhr