Abstract Based on the successful application and typical failure of FISHER intelligent valve positioner of Emerson Electric Company in the United States, this paper discusses the common faults of intelligent valve positioner for reference.
Key words intelligent valve positioner diagnostic function performance test failure 1 FisherDVC6000 intelligent valve positioner performance characteristics 1.1 DVC6000 series digital valve DVC6000 series digital valve controller (Figure 1 and Figure 2) is to communicate, based on micro-processing Electric - gas conversion instrument. In addition to the traditional function of converting a current input signal to a pneumatic output signal, the DVC6000 Series Digital Valve Controller also communicates via HART communication protocol. DVC6000 Series Digital Valve Controllers are designed to directly replace existing pneumatic or electro-pneumatic valve positioners. DVC6000 intelligent valve positioner is simple to use, compact and easy to install. The instrument is set up with a pushbutton and liquid crystal display (LCD) interface.
1.2 DVC6000 intelligent valve positioner performance characteristics (1) a wide range of applications - can be installed in Fisher and other manufacturers of straight stroke and rotary actuators.
(2) Self-diagnosis function - can provide the valve precision performance images (such as: instrument input signal, the actual position of the stem, to the actuator pressure). In the use of these information, not only to diagnose intelligent valve positioner itself, but also for the valve and the actuator installed on the diagnosis;
(3) Stabilization and optimization functions - instability inside the valve can be detected before the valve stroke shows instability, relative to the manual adjustment to more effective. The Performance Tuner can be set using the HART275 into the Auto Setup menu, completing the digital valve controller setup as prompted by HART275.
2 daily operation of intelligent valve positioner common fault description Our application of Fisher intelligent valve positioner, but also accumulated a lot of valuable experience, the following brief analysis of common part of the daily operation of the fault for reference.
2.1 sudden control valve does not move In June 2014, the control valve FV3121 instrumentation maintenance personnel suddenly found no opening, and timely contact with the craft staff to inspect the FV3121, fully technical safe production measures.
(1) check the valve instrument air source, check the air pressure is normal;
(2) Check the output of the positioner to the FV3121 membrane line, and found no air source in the gas pipeline, the positioner is not output.
FisherDVC6000 intelligent positioner in the process of inspection, found that the nozzle baffle is not angry, instrumentation staff concluded that the constant cut-off hole may be blocked, thus removing the purge with a gas source, the regulator valve back to normal operation .
2.2 Regulating valve position is not allowed In July 2013, during the inspection instrumentation maintenance staff to reflect LV3220 master and field valve position is inconsistent, the main control to 100%, the scene can only be opened to 50%. In the process of timely guidance under the guidance of the valve cut out after the valve and the positioner disconnected to strengthen the control valve signal, but the valve can be fully open, which shows that the valve is no problem, but also can be concluded The regulator may lose its linearity and should be re-calibrated. The regulator can be calibrated using HART475 for normal use. It can be seen in the initial installation or when the valve is disassembled often appear valve position error, in both cases may not be the adjustment of the positioner to the feedback lever fulcrum position problem. Therefore, for regulating valve position is not allowed, the use of HART475 adjustment, first find out the location of the feedback lever, the valve can be normal.
2.3 Regulating valve surge 20014 in December, the control valve FV3121 small opening 5% ~ 8% position oscillation, intelligent valve positioner output, the next cylinder pressure fluctuations. In chemical production, there are many reasons for the oscillation of the control valve, so the specific problems on the specific analysis, and the reason for the control valve is: the damping coefficient is not suitable, so staff to re-adjust the parameters using HART475, rapid protection of equipment Safe and stable operation.
2.4 control valve is not dead In May 2015, FV-103 closed lax. 4% ~ 5% opening, intelligent valve positioner air pressure 0.6MPa, the pressure on the cylinder 0.43 MPa, the next cylinder pressure 0.32MPa. Valve is not dead control valve is a common problem in routine maintenance. Solution: Regulating valve film to confirm no leakage and before and after the pressure is normal, the valve seat to confirm no wear and no foreign body between the card, the stem length is also appropriate, zero spring preload normal circumstances, check the valve Locator, if the locator output is found no signal, but the output pressure value is displayed on the instrument, thus concluding the locator fault reason:
(1) amplifier ball valve stuck, check, clean the amplifier can be;
(2) no matter Yan nozzle or baffle, so the nozzle position can be adjusted properly.
2.5 slow regulator valve As the output pressure of the positioner is not normal or slow and cause a slow regulator valve action. Therefore, we directly use the HART475 DVC6000 digital intelligent positioner calibration, if the effect is not obvious but also slow, use HART475 to improve the debugging results: Enter the AutoSetup menu interface, select Stabilize / Optimize (stability / optimization) or Performance Tuner (performance tuning optimization), if still dull, you can conclude that the localizer itself has failed, the specific failure may exist for four reasons:
(1) part of the rotating positioner stuck, no feedback force. Action: Lubricating oil by adding part of the surface treatment can be removed rotating stuck problem;
(2) amplifier ball valve is not strict, measures: is to check and clean the amplifier;
(3) output, input pipe leaks, treatment measures: air tightness check to eliminate air leaks;
(4) Membrane leak treatment measures: check the membrane chamber, replace the diaphragm.
3 Conclusion Both online regulator valve failure or practical problems in all aspects of smart valve positioner will be stronger than ordinary valve positioner. Intelligent locator performance has been significantly improved with new prototypes and microprocessors. And for the single-spring and spring-free double-acting actuators can be implemented; so intelligent valve positioner in the transformation more flexible, convenient, high precision, simple calibration, safe and reliable operation, small amount of routine maintenance, and the realization of DCS The direct communication greatly improves the dynamic characteristics and static characteristics of the regulating valve, improves the regulating performance of the regulating valve and enhances the enterprise management level.
References [1] Li Baohua. Intelligent valve positioner conventional mode and basic components [J]. Petrochemical Automation, 2010 (03).
[2] Guo Hong. Intelligent valve positioner application and development trend [J]. Shandong Industrial Technology, 2013 (12).
Author Institution Zhonghai Petrochemical Co., Ltd. Hainan Base Electric Instrument Department of Dong Fang City, Hainan Province 572600
Key words intelligent valve positioner diagnostic function performance test failure 1 FisherDVC6000 intelligent valve positioner performance characteristics 1.1 DVC6000 series digital valve DVC6000 series digital valve controller (Figure 1 and Figure 2) is to communicate, based on micro-processing Electric - gas conversion instrument. In addition to the traditional function of converting a current input signal to a pneumatic output signal, the DVC6000 Series Digital Valve Controller also communicates via HART communication protocol. DVC6000 Series Digital Valve Controllers are designed to directly replace existing pneumatic or electro-pneumatic valve positioners. DVC6000 intelligent valve positioner is simple to use, compact and easy to install. The instrument is set up with a pushbutton and liquid crystal display (LCD) interface.
1.2 DVC6000 intelligent valve positioner performance characteristics (1) a wide range of applications - can be installed in Fisher and other manufacturers of straight stroke and rotary actuators.
(2) Self-diagnosis function - can provide the valve precision performance images (such as: instrument input signal, the actual position of the stem, to the actuator pressure). In the use of these information, not only to diagnose intelligent valve positioner itself, but also for the valve and the actuator installed on the diagnosis;
(3) Stabilization and optimization functions - instability inside the valve can be detected before the valve stroke shows instability, relative to the manual adjustment to more effective. The Performance Tuner can be set using the HART275 into the Auto Setup menu, completing the digital valve controller setup as prompted by HART275.
2 daily operation of intelligent valve positioner common fault description Our application of Fisher intelligent valve positioner, but also accumulated a lot of valuable experience, the following brief analysis of common part of the daily operation of the fault for reference.
2.1 sudden control valve does not move In June 2014, the control valve FV3121 instrumentation maintenance personnel suddenly found no opening, and timely contact with the craft staff to inspect the FV3121, fully technical safe production measures.
(1) check the valve instrument air source, check the air pressure is normal;
(2) Check the output of the positioner to the FV3121 membrane line, and found no air source in the gas pipeline, the positioner is not output.
FisherDVC6000 intelligent positioner in the process of inspection, found that the nozzle baffle is not angry, instrumentation staff concluded that the constant cut-off hole may be blocked, thus removing the purge with a gas source, the regulator valve back to normal operation .
2.2 Regulating valve position is not allowed In July 2013, during the inspection instrumentation maintenance staff to reflect LV3220 master and field valve position is inconsistent, the main control to 100%, the scene can only be opened to 50%. In the process of timely guidance under the guidance of the valve cut out after the valve and the positioner disconnected to strengthen the control valve signal, but the valve can be fully open, which shows that the valve is no problem, but also can be concluded The regulator may lose its linearity and should be re-calibrated. The regulator can be calibrated using HART475 for normal use. It can be seen in the initial installation or when the valve is disassembled often appear valve position error, in both cases may not be the adjustment of the positioner to the feedback lever fulcrum position problem. Therefore, for regulating valve position is not allowed, the use of HART475 adjustment, first find out the location of the feedback lever, the valve can be normal.
2.3 Regulating valve surge 20014 in December, the control valve FV3121 small opening 5% ~ 8% position oscillation, intelligent valve positioner output, the next cylinder pressure fluctuations. In chemical production, there are many reasons for the oscillation of the control valve, so the specific problems on the specific analysis, and the reason for the control valve is: the damping coefficient is not suitable, so staff to re-adjust the parameters using HART475, rapid protection of equipment Safe and stable operation.
2.4 control valve is not dead In May 2015, FV-103 closed lax. 4% ~ 5% opening, intelligent valve positioner air pressure 0.6MPa, the pressure on the cylinder 0.43 MPa, the next cylinder pressure 0.32MPa. Valve is not dead control valve is a common problem in routine maintenance. Solution: Regulating valve film to confirm no leakage and before and after the pressure is normal, the valve seat to confirm no wear and no foreign body between the card, the stem length is also appropriate, zero spring preload normal circumstances, check the valve Locator, if the locator output is found no signal, but the output pressure value is displayed on the instrument, thus concluding the locator fault reason:
(1) amplifier ball valve stuck, check, clean the amplifier can be;
(2) no matter Yan nozzle or baffle, so the nozzle position can be adjusted properly.
2.5 slow regulator valve As the output pressure of the positioner is not normal or slow and cause a slow regulator valve action. Therefore, we directly use the HART475 DVC6000 digital intelligent positioner calibration, if the effect is not obvious but also slow, use HART475 to improve the debugging results: Enter the AutoSetup menu interface, select Stabilize / Optimize (stability / optimization) or Performance Tuner (performance tuning optimization), if still dull, you can conclude that the localizer itself has failed, the specific failure may exist for four reasons:
(1) part of the rotating positioner stuck, no feedback force. Action: Lubricating oil by adding part of the surface treatment can be removed rotating stuck problem;
(2) amplifier ball valve is not strict, measures: is to check and clean the amplifier;
(3) output, input pipe leaks, treatment measures: air tightness check to eliminate air leaks;
(4) Membrane leak treatment measures: check the membrane chamber, replace the diaphragm.
3 Conclusion Both online regulator valve failure or practical problems in all aspects of smart valve positioner will be stronger than ordinary valve positioner. Intelligent locator performance has been significantly improved with new prototypes and microprocessors. And for the single-spring and spring-free double-acting actuators can be implemented; so intelligent valve positioner in the transformation more flexible, convenient, high precision, simple calibration, safe and reliable operation, small amount of routine maintenance, and the realization of DCS The direct communication greatly improves the dynamic characteristics and static characteristics of the regulating valve, improves the regulating performance of the regulating valve and enhances the enterprise management level.
References [1] Li Baohua. Intelligent valve positioner conventional mode and basic components [J]. Petrochemical Automation, 2010 (03).
[2] Guo Hong. Intelligent valve positioner application and development trend [J]. Shandong Industrial Technology, 2013 (12).
Author Institution Zhonghai Petrochemical Co., Ltd. Hainan Base Electric Instrument Department of Dong Fang City, Hainan Province 572600
Screw and barrel are two essential components of plastic extrusion machines. They work together to melt and shape plastic materials into various forms. The screw is a rotating helical shaft that moves the plastic material through the barrel, which is a stationary tube. The screw and barrel are designed to work together to provide the right amount of heat, pressure, and shear to the plastic material. In this article, we will discuss the screw and barrel in detail and their importance in the plastic extrusion process.
The screw and barrel are essential components of plastic extrusion machines. They work together to provide the right amount of heat, pressure, and shear to the plastic material. The screw and barrel are designed to be precise and efficient, which results in high-quality plastic products.
The screw and barrel are also designed to be durable and long-lasting. They are made of high-quality materials that can withstand the high temperatures and pressures of the plastic extrusion process. The screw and barrel are also designed to be easy to clean and maintain, which reduces downtime and increases productivity.
Screw & Barrel,Extruder Barrel,Injection Molding Barrel,Extruder Screw Barrel
Shanghai Jiahao Machinery Manufacturing Co., Ltd. , https://www.jiahaoextruder.com