Habonim Catalog Interactive 2024 V04 15022024 - Catalog - Page 217
Minimum hysteresis / outstanding repeatability
Optimum control loop performance often hinges on a few carefully designed moving parts
within the valve assembly, and how well they work together. The most vulnerable areas in a
standard quarter-turn valve are the torque transmission shaft between the positioner and the
segmented ball (ball-stem, stem-adaptor, adaptor-actuator, actuator-positioner).
Considerable engineering expertise goes into the design and manufacture of these connecting
surfaces to provide the tightest fit possible, which in turn provides uniform movement of all
parts along the line of rotation.
Habonim carefully engineers all the adjoining parts to eliminate problems such as backlash,
leakage and hysteresis. The result is that the overall control unit has a maximum tolerance of
no more than 2%.
Test results measuring identical flow input from both directions illustrates the negligible
difference between up- scale and down-scale load.
Flow
Q2
Hysteresis
(∆Q)
Q1
Stroke (%)
60
100
Zero backlash adaptor - Optional (ZB)
Habonim’s Zero backlash adaptor design is based on the inherent flexibility
of stainless steel.
Actuator gear
Two grooves allow the adaptor to clamp the valve stem on one side,
whilelocking the actuator gear in place on the other side.
The Zero backlash adaptor ensures repeatability, zero backlash, and virtually
no hysteresis for the complete control unit.
Zero backlash adaptor
Thrust screw
+
Clamp screw
V-Port stem
Characterized ball
Deflection
CONTROL VALVES
217
