SAMSON valve positioner in stock supply

SAMSON valve positioner in stock supply

The SAMSON valve positioner consists of a feedback control system with valve stem displacement as the measurement signal and controller output as the set signal. The manipulated variable of this control system is the output signal from the valve positioner to the actuator. Used for important regulating systems with high quality requirements, to improve the positioning accuracy and reliability of regulating valves. When the medium being adjusted is high temperature, high pressure, low temperature, toxic, flammable, or explosive, in order to prevent external leakage, the packing is often pressed tightly, resulting in a large frictional force between the valve stem and the packing. At this time, using a locator can overcome the time delay.

SAMSON valve positioners are divided into pneumatic valve positioners, electric pneumatic valve positioners, and intelligent valve positioners based on input signals. The input signal of the pneumatic valve positioner is a standard gas signal, for example, a 20~100kPa gas signal, and its output signal is also a standard gas signal. The input signal of the electric valve positioner is a standard current or voltage signal, such as a 4-20mA current signal or a 1-5V voltage signal. The electrical signal is converted into electromagnetic force inside the electric valve positioner, and then the gas signal is output to the toggle control valve. The intelligent electrical valve locator converts the current signal output from the control room into a gas signal that drives the regulating valve. Based on the frictional force of the valve stem during the operation of the regulating valve, it offsets the unbalanced force caused by pressure fluctuations in the medium, making the valve opening correspond to the current signal output from the control room. It can also intelligently configure and set corresponding parameters to improve the performance of the control valve.

SAMSON valve positioners can be divided into one-way valve positioners and two-way valve positioners according to the direction of action. When a one-way valve positioner is used for a piston actuator, the valve positioner only works in one direction, while a two-way valve positioner acts on both sides of the cylinder of the piston actuator from two directions.

SAMSON valve positioners are divided into positive acting valve positioners and reverse acting valve positioners based on the gain sign of the output and input signals of the valve positioner. When the input signal of the positive action valve positioner increases, the output signal also increases, so the gain is positive. When the input signal of the reaction valve positioner increases, the output signal decreases, resulting in a negative gain.

According to whether the input signal of the valve positioner is an analog signal or a digital signal, it can be divided into ordinary valve positioners and fieldbus electrical valve positioners. The input signal of a regular valve positioner is an analog air pressure, current, or voltage signal, while the input signal of a fieldbus electrical valve positioner is a digital signal of the fieldbus.

According to whether the valve positioner is equipped with a CPU, it can be divided into ordinary electrical valve positioners and intelligent electrical valve positioners. Ordinary electrical valve positioners do not have a CPU, therefore they do not have intelligence and cannot handle related intelligent calculations. The intelligent electrical valve locator is equipped with a CPU, which can handle intelligent operations such as non-linear compensation for forward channels. The fieldbus electrical SAMSON valve locator can also be equipped with PID and other functional modules to achieve corresponding operations.

SAMSON valve positioner in stock supply

SAMSON valve positioners can also be classified based on the detection method of feedback signals.

For example, valve positioners that use mechanical linkages to detect valve position signals; Valve positioner for detecting valve stem displacement using Hall effect displacement detection method; Valve positioners that use electromagnetic induction to detect valve stem displacement, etc