
The Research Control® SRD991 top-mount valve positioner
While most valve positioners are side-mounted, the new top-mounted SRD991 uses a linear connection, which mitigates hysteresis between the positioner and actuator by better feeding back the actual position of a valve actuator, significantly improving flow control.
Top-mount valve positioners should be used when the application calls for high positioning accuracy or when greater force is required over the standard actuator, such as in the case of high shutoff pressures or excess packing friction. The SRD991 top-mount positioner is available with several valuable features including a LCD screen, protocols (HART, PROFIBUS-PA and FOUNDATION Fieldbus H1) and two levels of diagnostics. All the diagnostics settings can be easily configured and displayed by the positioner Device Type Manager (DTM). Moreover, the Positioner DTM enables a complete health report of the valve with full configuration and diagnostics data. The SRD991 positioner, therefore, allows an easy upgrade of any BLRA pneumatic positioner.
