Siemens intelligent electrical valve positioner debugging and common fault analysis valve positioner working principle introduction
In this paper, the principle of regulating valve and Siemens SIPART PS2 intelligent electrical valve positioner, debugging method steps, common fault analysis and treatment methods are introduced and analyzed in detail. 1 overview
Siemens SIPART PS2 intelligent electrical valve positioner (hereinafter referred to as positioner), by virtue of its simple man-machine dialogue interface, can be operated on the site through the keys on the positioner and LCD screen, the positioner is characterized by extremely low gas consumption, menu structure, easy to maintain, reliable performance, easy to master, The use effect is good, has been applied in the petroleum and petrochemical industry all over the country.
Combined with the engineering practice, this paper summarizes the debugging of intelligent locator and the common faults in the debugging process.
2 Basic Debugging Methods of Locators 2.1 Operation Panel
Before debugging the locator, you should first recognize the operation panel on the locator (Figure 1). A is the “small hand” key is the mode key, press and hold for 5 s to enter the locator setting boundary; B is for increment bond; C is the decrease key.
Figure 1 Siemens SIPART PS2 intelligent electrical valve positioner key diagram
2.2 Parameter Settings
When setting parameters, press the working mode key first and hold it for 5 seconds to enter the parameter setting interface. Press the working mode key once every time to enter the menu of the next parameter setting. If you want to change the specific setting value of a parameter, press the up button or down button for setting.
The common parameters of the locator menu are as follows:
Item “1.YFCT” function for angular stroke, straight stroke selection, click to build up or build down for selection. Turn is the angular stroke and Way is the straight stroke. The second item “2.YAGL” is the setting of the travel mode of the actuator. There are only two options for this setting: 33° and 90°. If the actuator has an angular stroke, it is set to 90° and if the actuator has a straight stroke, it is set to 33°. The third item “3.YWAY” trip range setting. 90° when the stroke is 20 mm; When the stroke is less than 20 mm, choose 33°. 4.INITA Automatic verification. When automatic check is needed, press and hold the “+” button for 5 seconds to perform self-check; The normal self-test consists of 7 steps, which are: the first step and the second step to determine the direction of motion (RUN 1); Step 3 check the displacement and adjust the zero and range (RUN 2); Step 4 Determine and realistic positioning time (RUN 3); Step 5 determine the ** small range (RUN4); Step 6 Optimize the transient reaction (RUN 5); Step 7 End of Self-test (FINSH). The fifth item 5.INITM is not recommended for manual verification. Item 6 “6.SCUR” SETS THE VALVE CURRENT RANGE. 0 m A is 0 to 20 m A, 4 m A is 4 to 20 m A. The seventh item “7.SDIR” set value direction. According to 4~20 mA signal valve movement direction setting, reaction choose fall, positive action choose rise. The tenth item “10.TSUP” set value is inclined to rise, select auto. Item 12 “12.SFCT” set point function. Choose Lin for the direct stroke and N1-50 for the angular stroke (inherent characteristics). Item 38 “38.YDIR” displays and location feedback the direction of controlled variables. Travel direction setting (feedback valve position displayed by positioner) :fall down; Rise up. 39.YCLS is tightly closed by controlled variables. Item 50 “50.PRST” reset setting. If the Settings of the above parameters are not correct during debugging, you can press and hold the Add key (+) under this state. When the LCD displays “OCAY”, the reset is successful.
3 Common faults and troubleshooting methods
Type: if the positioner exhaust has been vented, then the input and output pipe may be connected in reverse.
Second: if the valve surge, the balance may not be found, there is a leakage phenomenon, the scene of valve surge is more than 90% of the locator output air source pipe leakage caused.
Third: if the 4~20 m A signal received by the positioner is not consistent with the actual direction of action of the field valve, then adjust the 7 and 38 items of the parameter Settings in the menu respectively, until the control room and the field are consistent.
(3) If the valve can not go through the first step or the second and third steps can not go through occasionally, it is likely that there is a problem with the valve feedback rod. The screw of the feedback rod is not tight or the screw is not in the sliding groove of the feedback rod. At this time, we need to find the feedback rod in the right position and tighten the screw, and the self-test should be able to proceed normally.
Figure 2 Siemens SIPART PS2 intelligent electrical valve positioner wheel position diagram
(4) In other cases, when the dead zone is encountered, the pulley can also be moved in the self-test process of the locator to make it pass.
4 conclusion
Through our many years of Siemens SIPART PS2 intelligent electrical valve positioner debugging site and the debugging process of various problems encountered in the analysis and summary, summed up these debugging process methods and fault handling experience. It is hoped that the debugging process and troubleshooting method mentioned in this paper can have certain reference value and function for instrument peers or debugging personnel.
Working principle of the valve positioner is introduced the valve positioner, according to the structure of the pneumatic valve positioner, electric valve positioner and intelligent valve positioner, is the main control valve accessories, usually with pneumatic control valve, it accepts the regulator output signal, and then to its output signal to control the pneumatic control valve, when the regulator action, The displacement of the valve stem is fed back to the valve positioner by the mechanical device, and the valve position is transmitted to the upper system by electrical signal.
According to the structure by pneumatic valve positioner, valve positioner, electric valve positioner and intelligent valve positioner, is the main control valve accessories, usually with pneumatic control valve, it accepts regulator output signal, and then to its output signal to control the pneumatic control valve, when the regulator, the displacement of the stem and the machinery through feedback to the valve positioner, The valve position is transmitted to the upper system by electrical signal.
Valve positioner according to its structure form and working principle can be divided into pneumatic valve positioner, electric-gas valve positioner and intelligent valve positioner.
Valve positioner can increase the output power of the regulating valve, reduce the transmission lag of the regulating signal occurs, accelerate the movement speed of the valve stem, can improve the linearity of the valve, overcome the friction of the valve stem and eliminate the influence of unbalanced force, so as to ensure the correct positioning of the regulating valve.
Valve positioner classification:
Generally can be divided into pneumatic valve positioner, electrical valve positioner and intelligent valve positioner.
Valve positioner is divided into pneumatic valve positioner, electric valve positioner and intelligent valve positioner according to the input signal. The input signal of the pneumatic valve positioner is the standard gas signal, for example, 20~100kPa gas signal, its output signal is also the standard gas signal. The input signal of the electrical valve positioner is the standard current or voltage signal, for example, 4~20mA current signal or 1~5V voltage signal, etc., the electrical signal is converted into electromagnetic force inside the electrical valve positioner, and then the output gas signal to the toggle control valve. Intelligent electrical valve positioner it will control room output current signal into the drive regulating valve gas signal, according to the valve stem friction when working, offset medium pressure fluctuation and unbalanced force, so that the valve opening corresponding to the control room output current signal. And the corresponding parameters can be set by intelligent configuration to improve the performance of the control valve.
1 pneumatic valve positioner:
The utility model relates to a valve positioner that converts electrical signals into pressure signals and controls the opening of the valve with compressed air or nitrogen as the working air source.
2. Electrical valve positioner:
The DC current signal given by the control system is converted into the gas signal driving the regulating valve to control the action of the regulating valve. At the same time according to the opening of the valve feedback, so that the valve position can be correctly positioned according to the system output control signal.
3. Intelligent valve positioner:
The utility model relates to a valve positioner that does not need manual adjustment, can automatically detect the zero, full range and friction coefficient of the regulating valve, and automatically set control parameters.
According to the direction of action can be divided into one-way valve positioner and two-way valve positioner.
The one-way valve positioner is used in the piston actuator, the valve positioner only works in one direction, the two-way valve positioner works on both sides of the cylinder of the piston actuator, in two directions.
According to the valve positioner output and input signal gain symbol is divided into positive valve positioner and reaction valve positioner. As the input signal to the positive-acting valve positioner increases, the output signal also increases, so the gain is positive. Reaction valve positioner input signal increases, the output signal decreases, therefore, the gain is negative.
According to the valve positioner input signal is analog signal or digital signal, can be divided into ordinary valve positioner and field bus electrical valve positioner. The input signal of the common valve locator is the analog pressure or current, voltage signal, the input signal of the fieldbus electrical valve locator is the digital signal of the fieldbus.
According to whether the valve positioner has CPU, it can be divided into ordinary electrical valve positioner and intelligent electrical valve positioner. Common electrical valve positioners do not have CPU, therefore, do not have intelligence, can not handle the relevant intelligent operations. Intelligent electrical valve positioner with CPU, can deal with the intelligent operation, for example, can carry forward channel nonlinear compensation, etc., fieldbus electrical valve positioner can also take P>
Working principle of valve positioner:
Valve positioner can increase the output power of the regulating valve, reduce the transmission lag of the regulating signal occurs, accelerate the movement speed of the valve stem, can improve the linearity of the valve, overcome the friction of the valve stem and eliminate the influence of unbalanced force, so as to ensure the correct positioning of the regulating valve.
Working principle of valve positioner
The valve positioner is the main accessory of the control valve. It takes the valve stem displacement signal as the input feedback measurement signal, takes the controller output signal as the setting signal, compares, when the two have the deviation, changes its output signal to the actuator, makes the actuator action, establishes the valve stem displacement and the controller output signal between the one-to-one correspondence. Therefore, the valve positioner consists of a feedback control system with the stem displacement as the measurement signal and the controller output as the setting signal. The control variable of the control system is the output signal of the valve positioner to the actuator.
Post time: Sep-20-2022
