Series 73 Built-In Valve Positioners  
This line of compact 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 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.