This line of compact pneumatic valve positioner instruments incorporates a single-axis, force-balance principle of operation to ensure accurate and stable control valve positioning. In all cases, including bottom-loading applications, a Model 73 Built-In Pneumatic Valve Positioner is mounted directly on the topwork of the valve, with no external levers or other exposed mechanisms.
By selecting the appropriate range spring from the wide selection, almost any combination of valve stroke (from 1/4" to 4") and instrument span (from 2 to 24 psi) can be obtained.
Single-axis, force-balance principle of operation, ensures accurate and stable positioning
Feedback circuits direct the actuator's position, ensuring adherence to the control instrument signal
Range spring capability accomodates a wide variety of valve strokes and instrument spans
Model 74 Pneumatic Valve Positioners are universal positioners that provide versatility, dynamic performance, and high positioning accuracy. Supply pressure variations have little or no effect on the positioner output, which eliminates the need for a supply pressure regulator.
Double-acting or single-acting service accomodates installation in a variety of environments
Field reversibility reduces downtime and simplifies maintenance
Choice of continuously adjustable standard stroke ranging from 1/4" to 48" and continuous span and zero adjustability within range spring limits provide application versatility
Extra high capacity pilots ensure maximum frequency response and optimum stroking speeds for all actuator sizes
Negative feedback pilot circuit allsw the positioner to operate with a push-pull gain of more than 900:1 (uisng 100 psig supply) with no sacrifice in stability (gain of 650:1 with 74S models)
Find your local sales representative for Siemens Process Instrumentation
Customer Care (USA): 1-800-365-8766
USA Service and Support Call Center: 1-800-333-7421