Abstract: Disclosed examples include sending commands to a positioner to stroke a valve over different ranges of travel; determining a plurality of pressure differences corresponding to the different ranges of travel; selecting a control step size for the valve based on the pressure differences; and selecting a gain value of the positioner based on the control step size.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for automatically determining friction of a control valve. An example method includes measuring first and second pressures corresponding to respective first and second positions of a valve while stroking the valve in a first direction, measuring third and fourth pressures corresponding, respectively, to the second and first positions while stroking the valve in a second direction opposite the first direction, determining a first pressure difference between the second and third pressures, determining a second pressure difference between the first and fourth pressures, determining an average pressure based on the first and second pressure differences, comparing the average pressure to a third pressure difference corresponding to a range of travel of an actuator including the first and second positions, and determining a control step size for the valve based on the comparison.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for automatically determining friction of a control valve. An example method includes measuring first and second pressures corresponding to respective first and second positions of a valve while stroking the valve in a first direction, measuring third and fourth pressures corresponding, respectively, to the second and first positions while stroking the valve in a second direction opposite the first direction, determining a first pressure difference between the second and third pressures, determining a second pressure difference between the first and fourth pressures, determining an average pressure based on the first and second pressure differences, comparing the average pressure to a third pressure difference corresponding to a range of travel of an actuator including the first and second positions, and determining a control step size for the valve based on the comparison.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for automatically determining friction of a control valve. An example apparatus includes a hysteresis measurement controller to determine an average control hysteresis value for a valve over a first range of travel of the valve, a comparator to compare the average control hysteresis value to a second value corresponding to a second range of travel of the valve encompassing the first range of travel of the valve, and a step size selector to select one of multiple control step sizes for the valve based on the comparison.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for automatically determining friction of a control valve. An example apparatus includes a hysteresis measurement controller to determine an average control hysteresis value for a valve over a first range of travel of the valve, a comparator to compare the average control hysteresis value to a second value corresponding to a second range of travel of the valve encompassing the first range of travel of the valve, and a step size selector to select one of multiple control step sizes for the valve based on the comparison.

Abstract: A high resolution pulse count interface is situated between a positive displacement (PD) meter and a flow computer. A magnetic wheel attaches to the PD meter, with the interface using Hall Effect sensors to detect the rotation of the wheel. A pulse prediction algorithm and weighting algorithms are used to improve resolution for the flow computer to enable real time flow rate calculations.