Failure modes, effects and hazard analysis (FMECA) _ Anyang steel iron-making plant inspection station

Category: discussion on wrongful death attorneys floridacheck failure modes, effects and hazard analysis (FMECA) is against all possible failures, and according to the analysis of failure modes, determine the impact of each failure mode to identify single points of failure and failure modes of a grim and probabilities to determine its hazards. The so-called single points of failure is caused product failures, and there is no redundancy or partial failure of the alternative procedure as a remedy. FMECA include failure mode and effects analyHelp Desk Tracking Softwaresis (FMEA) and hazard analysis (CA). failure mode and effects analysis (FMEA) is in the product design process, through the vaapplication business card creditrious components of the product potential failure modes and their analysis of the impact on product features, and raised the possibility of improved prevention measures, a design to improve product reliability analysis methods. hazard analysis (CA) is identified in the FMEA for each failure mode effect according to its category and severity of occurrence probability of combined impact analysis, to thoroughly evaluate the possible failure modes and effects. CA is continuation of FMEA, depending on the product structure and reliability of data access, CA can also be a quantitative analysis can be analyzed on a regular basis. FMECA analysis method can be used for the entire system to the components in any levels, generally upon request and may be provided on the product level. failure mode means that components or a manifestation of product failures. Is usually a symptom that can be observed. If broken, poor contact corrosion, short, and so on. effect refers to the failure modes may cause failure on safety, the impact of product features. Failure in General can be divided into: to topical, high level and ultimately impact on three levels. Analysis of aircraft hydraulic systems of a hydraulic pump, it a slight oil leakage of failure mode, the pump itself on local effects may be less efficient, for high level to the hydraulic system pressure of impact can be reduced, the ultimate impact that might have no effect on the aircraft. harsh refers to the severity of some sort of failure modes and effects. will generally be divided into four classes: class I (catastrophic failure), it is a cause of death of, or the system (such as airplane) destroying failures. Class �� (deadly failure), which is a cause severe injury, equipment or system is seriously damaged, so that the task failed failure. Category III (catastrophic) such failure may cause mild mild injuries of personnel, equipment and systems damaged, resulting in deferred execution, or indent a task, or the system does not work (such as an airplane flying by mistake). IV (fault mildly), the severity of such a failure is not sufficient to cause injuries, damaged equipment or system, but need an unscheduled maintenance or repair. FMECA implementation procedures usually are: (1) the structure and function of the product-related information available. (2) the product launch, operation, operation and maintenance information available. (3) the environmental conditions of the product information available. such information in the initial stages of design, often cannot grasp. At the beginning, but to do certain assumptions used to determine some obvious failure mode. Instant preliminary FMECA is also noted that many single points of failure parts, and some of them can eliminate through the structure of the new arrangements. As the design progresses, available information is constantly increasing, FMECA should be repeated, if necessary, and may expand the analysis to a more specific level. (4), defines the product and its features, and minimum requirements. Complete definition of a system including major and minor features, uses, expected performance, environmental requirements, and system constraints constitute a fault condition. For any given product has one or more patterns, and may be in different stages of the work, therefore, the system also includes the definition of each mode of the work and its continuing work in the function description. Functional block diagram of each product should have it, indicates that the product and product relationships between the various functional units. (5) in accordance with the functional block diagram draw their reliability block diagram. (6) according to the structure and needs analysis of available data to determine the number of levels, which provides analysis of levels. (7) to identify failure modes, analysis of their causes and effects. (8) identify fault detection method. (9) to find out when design possible preventive measures in order to prevent undesired events. (10) to determine failure modes and damage to the products of various severities. (11) identify various failure modes of occurrence probability level. Probability of failure mode occurs in General can be divided into: class a (regular), occurred in the course of work of the probability is very high, that is, a failure modes and the probability of occurrence is greater than the overall failure rate of 0.2. B-class (highly probable), a medium probability of failure during the work, that is a total failure probability of failure modes and the probability of occurrence for 0.1-0.2. C-level (occasional), when a fault occurs in the course of work accidentally, that is a total failure probability of failure modes and the probability of occurrence of 0.01-0.1. Class d (rare), product failures that occurred during the probability is very small, that is a total failure probability of failure modes and the probability of occurrence of 0.001-0.01. E-class (very unlikely), the probability of failure during the working period is close to zero, that is, the probability of a failure mode occurs less than 0.001 for total failure probability. (12) completed FMEA sheet, and draw the hazard matrices, if you need to make a quantitative FMECA, you will need to fill in the form CA. If only the FMEA, (11) steps and draw the hazard matrices do not have to do. Above outlines the basic FMECA need to enter information, and standards on the basis of the further reference to complete the analysis, you can reference standards are national standards GB7826-87 the system reliability, failure mode and effects analysis (FMECA) program, the International Electrotechnical Commission standard IEC60812Ed.2 (2003) and the national military standard GJB1391 of the failure modes, effects and the hazard analysis program, provides these standard forms for use by the analyst. failure (fail) tree analysis (FTA) and FMECA similar, fault tree analysis (FTA) is the analysis of product failure between cause and effect relationship of another important reliability analysis, fault tree analysis was first introduced in 1961 for the analysis of "militia" missile launch control system, later, popularization and application of nuclear energy, aeronautics, aerospace, and many other areas. Performing when it comes to health and safety standards, and on major accidents (such as fire, etc) should also be analysis of the FTA. Fault tree indicate those components of the product failure modes or external event or their combinations lead to a given failure mode of logic diagrams. It with a series of events, symbols, logical and transfer symbols describing various causal relationships between events in the system. General requirements for fault tree is as follows: (1) fault tree analysis preparation for analysis must be familiar with the design specifications, design drawings, operating procedures, maintenance procedures and other relevant information. Mastering system structure, function and design intent, State of the environment. According to system complexity and requirements and, if necessary, should make the system FMEA and FMECA to help identify top events and the levels of failure events, depending on the system analysis of task requirements and understanding of the system to determine purpose, depending on the system task to determine whether a system failure criteria. (2) of fault tree construction to complete (1) when you are working in, you can proceed from determines the top events, follow the basic rules and method of fault tree construction to build out the needed fault tree. (3), fault tree analysis of fault tree analysis mainly includes the following: Standardization of fault trees; modular decomposition and fault tree simplified computing minimal cut sets of fault trees. (4), fault tree analysis based on the occurrence probability of fault tree at the end of the event, to calculate the top event probability. (5) write fault tree analysis report due to a fault tree analysis has become an important tool for system reliability analysis, and is widely used by reliability engineers, both at home and abroad has also issued a corresponding standards, these standards: national standard GB/T7829-1987 of the fault tree analysis program of the national military standard GJB768 of the fault tree analysis, IEC International Electrotechnical Commission standard 61025Ed.1-1990-10 of the fault tree analysis. Maintainability design for product repairing is designed only maintainability design in product design and development process and analytical work, maintenance can be designed into the product. Maintainability design main methods include both qualitative and quantitative methods. Maintainability design is the most important qualitative, as long as designers of maintainability of consciousness, and maintainability engineering experience can be designed into the product. Qualitative and design simplifies maintainability design, accessibility, and standardized interchangeable and modular design, Poka yoke and identifying security design for logo design, maintenance, fault detection, human effects in maintenance engineering. (1) simplified design is in meeting performance requirements and the requirements of the use of a premise, structure and appearance of the simplest as possible, to reduce the use and maintenance of skills requirements. Simplified design are simplified as much as possible the basic principle of product features, merging product functionality and minimize the variety and number of parts. (2) design is when products fail accessibility for maintenance accessible repair parts of the design you want. Accessibility design requirements of the "visible"--Visual up; "reach"--an entity can be up to, for example, some parts of the body or with the access to repair parts, maintenance operations while leaving enough time. To set the maintenance window and maintenance access is the solution "can be seen, and reach the" important way. Accessibility and design principles: �� arrangement, the reasonable layout. Fault rate high, maintenance space needs large of parts as far as possible arrangements in system of external or easy close to of parts; �� for avoid all parts maintenance Shi cross job and interference, available counter, and spot cabin or other forms layout; �� as far as possible do check or maintenance any a parts Shi, does not demolition and does not mobile or less demolition and less mobile other parts; �� products all parts of disassembly and Assembly to easy, disassembly and Assembly Shi parts of into and out of route best is line or gentle of curve; �� products of check points, and test points, and check Windows, and lubrication points, and added mouth, maintenance points are should layout in easy close to of location Shang; �� needs maintenance and disassembly and Assembly of parts around to has enough of space; �� maintenance channel mouth or hatch of design should makes maintenance operations as possible simple convenient; �� maintenance Shi General should can saw internal of operations, its channel except can holds maintenance personnel of hand and arm outside, also should stay has appropriate of gap to for observation. (3) standardization and interchangeability of modular design. Standardized designs are modern characteristics of product design, the design-time as far as possible using standard components to parts of the supply of reserves and dispensing, and make product maintenance more simple and easy. interchangeability between the design refers to the same product on the entities, performance can be interchanged with each other on the function. Interchangeability is designed to simplify maintenance and spare parts costs savings, improve maintainability. modular design is the effective way to realize General, rapid replacement repair parts swaps. Module is detached from the products individually, have relatively independent function structure. Advanced modular hardware design coefficients of 70%-more, advanced modular software design coefficients of 50% above. (4) prevention of errors and identify logo design. Mistake-proof design is to ensure that is structured to allow only loaded to load up, wrong or installed backwards put up, or when an error occurs it can immediately identify and correct. Identify logo design is in maintenance and spare parts, spare parts, special tools and test equipmentIdentified above, so that differences identified to prevent confusion, to avoid errors and accidents, but also can improve work efficiency. (5) maintain security design. Maintenance refers to security design can avoid maintenance, personal injury, or damage to the product design. For example, in a potentially dangerous part, should provide a visible mark, warning lights, sound alerts and other auxiliary means of prevention. Dressed in high pressure gas, springs, with higher voltages there is such a great energy and maintenance to be pulled down to the device, there should be alternative energy structure and safe disassembly and Assembly of equipment, tools, and to ensure the safety of disassembly and Assembly. Maintainability design should take into account at the same time defending against mechanical injury, electric shock, fire, explosion and anti-virus in order to guarantee the safety of maintenance personnel. (6) design of fault detection. Fast and simple maintenance fault detection and diagnosis is accurate have a significant impact. Design should be fully taken into account when testing methods, test equipment, test the configuration, a range of issues, in order to improve the speed of location of the fault. (7) in the maintenance of human factors engineering. In the maintenance of human factors engineering (human factors engineering for short) is the study of human factors in maintenance, including physiological factors, psychological factors, and the relationship between body size and product to improve maintenance productivity, reduce maintenance problems such as fatigue.