On predictive maintenance of Siemens instruments

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On predictive maintenance of Siemens instruments

mode of equipment maintenance

equipment maintenance generally has three modes: post maintenance, preventive maintenance and predictive maintenance

post maintenance, also known as "remedial maintenance", "maintenance after failure", "operation to failure management", as the name suggests, that is, repair the equipment when it fails. This is the most elementary and simple maintenance and operation method that is currently used by users in China. To be exact, this is a "maintenance free" management method. It is also the most expensive maintenance and management method. The analysis shows that the cost of maintenance in reactive or post maintenance mode is three times that of the same maintenance in planned or preventive maintenance mode. A literature review reported that the cost of the same maintenance after artificial intervertebral disc implantation

preventive maintenance and predictive maintenance belong to prior maintenance. Generally speaking, preventive maintenance can be divided into three types: time-based maintenance plan, performance-based maintenance plan and condition based maintenance plan. The problem with this method is that the operating mode and the variables related to the system or device will directly affect the normal working life of the machine. At the same time, there are also a large number of facts that show that frequent disassembly and shutdown maintenance not only lead to reduced production and increased maintenance costs, but also greatly reduce the actual service life of the equipment

predictive maintenance (PM) is also called predictive maintenance or strategic maintenance. Predictive maintenance, which integrates equipment condition monitoring, fault diagnosis, fault (state) prediction, maintenance decision support and maintenance activities, is a new advanced maintenance method in recent years. Predictive maintenance is actually an operation driven preventive maintenance program. Predictive maintenance does not rely on the average life statistics (i.e. mean time between failures) in the industry or the factory to plan and arrange maintenance activities, but directly monitors the operation status, efficiency, heat distribution and other indicators to determine the actual mean time between failures or the efficiency loss that will endanger the operation of all key system devices in the overall upgrading facilities of the factory or the new material industry

compared with preventive maintenance, predictive maintenance has obvious advantages: 1. Overcome the blindness of preventive maintenance and have strong pertinence. Adopt different treatment methods according to different states to reduce the operation and maintenance costs. 2. Reduce downtime (total maintenance), improve the reliability and availability of equipment, extend the service life of equipment, and better implement the policy of "safety first, prevention first". 3. Reducing maintenance workload and labor intensity is conducive to reducing staff and increasing efficiency and improving economic benefits

current situation of predictive maintenance

in the past few years, with the rapid development of instruments and meters based on microprocessors or computers, and the continuous improvement of maintenance management systems, especially the rapid development and popularization of advanced field bus and industrial Ethernet communication technologies, major manufacturers at home and abroad have introduced various advanced predictive maintenance technologies, with more than 33500 employees of Evonik creating sales of about 12.7 billion euros. Dr. Fitch of the United States created the concept and theory of proactive maintenance on the basis of predictive maintenance

predictive maintenance can be divided into narrow sense and broad sense in the connotation and extension of the concept. Predictive maintenance in a narrow sense is based on "condition monitoring" and emphasizes "fault diagnosis", which refers to irregular or continuous condition monitoring of equipment, finding out whether there is abnormal condition or fault trend of equipment according to its results, and then arranging maintenance in a timely manner; Generalized predictive maintenance integrates condition monitoring, fault diagnosis, condition prediction and maintenance decision-making. Condition monitoring and fault diagnosis are the basis, condition prediction is the focus, and maintenance decision-making obtains the final requirements of maintenance activities. It is a systematic process. It brings maintenance management into the category of predictive maintenance. Consider the whole maintenance process until the contents related to maintenance activities are obtained

Siemens instruments achieve predictive maintenance

in recent years, Siemens has designed and developed many instrument products with a high degree of intelligence around the concept of predictive maintenance

sitrans DA400 pump diagnosis system

for most slurry pumps with strong transportation wear, effective low-cost maintenance has always been a problem. The instrument SITRANS DA400 introduced by Siemens based on sound sensitive diagnosis and PROFIBUS technology can effectively provide predictive maintenance solutions for pumps

sitrans DA400 sound sensitive detection system provides an excellent solution for reciprocating diaphragm coal slurry pump to detect the operation of suction valve and discharge valve. SITRANS DA400 uses the sound level of the detected cavitation phenomenon and the corresponding pump operation noise to diagnose whether the opening and closing actions of the valve are intact. SITRANS DA400 condition based maintenance requires monitoring the working conditions of the device or operation unit. Its advantages are: damage can be found before the device fails; You can make a @d host 1 must be grounded and a shutdown maintenance plan; Have been repaired before costly damage occurs; Extend the service life of components and realize the automatic inspection of devices or units

according to the experimental observation on site for more than half a year, the average maintenance time of the diaphragm pump with SITRANS DA400 installed is about 2/3 less than that of the two groups of diaphragm pumps without installation, which is equivalent to reducing the maintenance cost by 2/3, and greatly prolonging the service life of the equipment

sipart PS2 intelligent valve positioner

how to realize predictive maintenance of valves through the diagnostic function of intelligent valve positioner is a problem concerned by many users now. The fault diagnosis of the intelligent valve positioner to the regulating valve is completed by adding sensors. The microprocessors inside the positioner collect the data of various sensors at a fixed time, calculate, compare, analyze and configure various data, and output alarm signals through configuration software for abnormal information. The diagnosis of intelligent valve positioner for regulating valve is divided into diagnosis and off-line diagnosis

diagnosis includes: stroke accumulation, number of changes in stroke direction, number of alarms, dead band self adjustment, valve baseline position (such as wear of valve seat), hours of operation at the highest and lowest temperature, number of operations of piezoelectric valve, valve positioning time, actuator leakage, noise diagnosis, etc. The off-line diagnosis includes: the tightness, static characteristics, step transition and frequency response characteristics of the actuator and gas circuit

in addition, SIPART PS2, an intelligent electric valve positioner, provides more additional monitoring functions, and the status display is derived from the monitoring of fault signals. Fault signals are classified according to the mode of "traffic lights" and are represented by green, yellow and red wrenches, which enables users to detect the valve or actuator in advance before major faults occur, and can avoid system shutdown. Through the indication of fault signals, such as actuator diaphragm damage, action lag, etc., users can use appropriate maintenance strategies to ensure the reliability of the system

sitrans cls300 capacitive level switch

in industries such as pharmaceutical, chemical fertilizer, nonferrous metals, petrochemical and so on, due to the strong adhesion and wear of many measuring media, a lot of additional maintenance costs are increased

Siemens has therefore introduced a capacitive level meter with PROFIBUS bus, which analyzes the key data such as the hanging amount of the field probe (the change of zero capacitance), the wear of the probe (the change of accumulated capacitance), and transmits a large amount of diagnostic information to the upper computer through the field bus to help users formulate predictive maintenance plans, greatly saving users' maintenance costs. At the same time, due to the reduction of the number of parts replaced, It also extends the actual service life of the equipment. This function is difficult to realize for instruments that can only output switching signals

siwarex weighing system

different from the traditional weighing system, SIWAREX weighing system is actually a set of digital weighing solutions fully integrated in SIMATIC system. Compared with the traditional weighing system, SIWAREX system breaks through the limitations of communication and system structure, and shows great technical advantages in system measurement accuracy, control speed, construction cycle, long-term maintenance, etc

the new SIWAREX system provides a very conceptual and ideal tool for most users. The process and status of weighing are recorded in real time through the event recording function, and abnormal events are analyzed. At the same time, the diagnostic buffer will record and save the last 100 diagnostic messages. Through the long-term continuous monitoring of the key parameters of the symmetrical weight sensor and cable, we can get the pre diagnostic information about the weighing system, so as to avoid sudden and expensive equipment shutdown faults and reduce the maintenance cost. These functions of SIWAREX are undoubtedly an ideal supplement for the evaluation and diagnosis of process data. (end)

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