Preventing Failure

It follows from most premature failures being attributable to human error, that most such failures could be prevented by appropriate action at the design, material selection and production stages. Leaving aside lapses in quality control, this means selecting materials and a design that are satisfactory for the service conditions, which in turn imphes that an analysis needs to be carried out to make predictions of the long term performance of the product. 

There are undoubtedly intrinsic problems in reliably predicting service lifetime of rubbers due to the uncertainty of, and variation in, the service conditions and the timescales for which products are expected to perform. However, the three basic approaches to assessing service life are  

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Breakdown maintenance is suitable for equipment whose failure does not threaten production, safety or the environment, and where the cost of preventing failure would be greater than the consequence of failure. In this case, the equipment would be repaired either on location or in a workshop. Even with this policy, it is assumed that the recommended lubrication and minor servicing is performed, just as with a motor car. 

Evidence of localized corrosion can be obtained from polarization methods such as potentiodynamic polarization, EIS, and electrochemical noise measurements, which are particularly well suited to providing data on localized corrosion. When evidence of localized attack is obtained, the engineer needs to perform a careful analysis of the conditions that may lead to such attack. Correlation with process conditions can provide additional data about the susceptibility of the equipment to locaHzed attack and can potentially help prevent failures due to pitting or crevice corrosion. Since pitting may have a delayed initiation phase, careful consideration of the cause of the localized attack is critical. Laboratory testing and involvement of an... 

Several approaches are available to eliminate this problem. If stresses cannot be sufficiently reduced, a metal possessing greater resistance to caustic SCC can be specified for replacement tubing. Alteration to the environment, such as eliminating alkalinity or increasing system pressure to prevent flashing (thereby minimizing the potential for concentration of caustic), would also prevent failure by this mechanism. 

Has the facility established an effective critical-equipment maintenance program (also termed mechanical integrity program) to prevent failures that would cause hazardous conditions ... 

Cleaning also prevents failures due to abnormal operating modes. Fouling of the rotor blades on turbines can cause thrust-bearing failures. Deposits on... 

It is often deemed that quality assurance serves prevention and quality control detection, but a control installed to detect failure before it occurs serves prevention, such as reducing the tolerance band to well within the specification limits. So quality control can prevent failure. Assurance is the result of an examination whereas control produces the result. Quality assurance does not change the product, quality control does. 

Do the design controls ensure that design and development activities are planned so as prevent failure and secure success ... 

Prevention costs - cost incurred in preventing failure, such as planning, training, FMEA, FTA, SPC, MSA... 

Provisions made to prevent failure to satisfy customer needs and expectations and organizational goals. 

These incidents show that, to prevent failures of FRP tanks, we should ... 

This type of compressor will continue to compress the air volume in the down-stream system until (1) some component in the system fails, (2) the brake horsepower exceeds the driver s capacity, or (3) a safety valve opens. Therefore, the operator s primary control input should be the compressor s discharge pressure. If the discharge pressure is below the design point, it is a clear indicator that the total down-stream demand is greater than the unit s capacity. If the discharge pressure is too high, the demand is too low and excessive unloading will be required to prevent failure. 

While preventive maintenance is concerned with regularly testing, and reconditioning equipment to prevent failures in service and premature deterioration, it follows that predictive maintenance procedures are concerned with the ability to predict when the equipment will fail and then developing schedules to implement timely repairs. Predictive maintenance does not imply that with the use of these techniques, failure modes in equipment can be prevented rather, it suggests that the occurrence of failure can be predicted and thus planned for. An appropriate example would be the inspection and change of a major compressor face-type oil seal where random heat checking (FM) has been observed over the years. 

From inspection of the three designs it is apparent that the main stress of the loading will be at the support point for the seat. This will be assumed to be sufficiently strengthened to prevent failure, either by excessive stress or bending at the support point. The analysis will be concerned with the fact that the seat itself will not break as a result of the load and will not sag excessively after continued use. For this example the impulse load caused by dropping into a chair will be ignored. 

It will be constructed or lined with material compatible with the waste and with sufficient strength to prevent failure from pressure, climate, traffic, and daily use. 

To prevent failure due to the disengagement of the pane out of the frame, bite or edge engagement depths are required. They are based upon the assumption that the plate will distort as a spheroid surface. At the maximum design center deflection of 15 pane thicknesses, this conservatively approximates the deflection shape function. To be conservative, a 0.5-inch safety margin is added to all calculations. 

One has to consider that all connected devices must also withstand the maximum explosion overpressure. The NFPA 69 Standard, Explosion Prevention System, 1997 European Standard prEN 14460, Explosion Resistant Equipment, 2005 and Kirby and Siwek, Preventing Failures of Equipment Subject to Explosions, Chemical Engineering, June 23, 1986, provide excellent guidance on the practice of containment. 

HSE, 1995. Out of control (why control systems go wrong and how to prevent failure), HSE books. 

If the pipe fluid continues to flow, internal convection is often sufficient to prevent failure, with the temperature reaching equilibrium below the failure temperature. However, this is not invariably the case. 

Water from water spray or deluge sprinklers is highly effective when applied on steel decks for pool fires, and can be expected to prevent failure. In jet fires, it has relatively little effect on the failure time. 

Fire protection systems achieve exposure protection by absorption of heat through application of extinguishing agents to structures or equipment exposed to a fire. The application of some extinguishing agents removes or reduces the heat transferred to the structures or equipment from the exposing fire, as well as limits the surface temperature of exposed structures and equipment to a level that will minimize damage and prevent failure. 

Exposure protection—Application of water to a surface to minimize damage and prevent failure from a fire in an adjacent area. 

What tools and fixtures are required to prevent failures and reduce the risk ... 

What education is needed for participants, innovators, engineers, and process owners, such as line management and operators, to reduce or prevent failures ... 

The quality objectives are well defined to prevent defects or errors occurring during the whole process and to prevent failure of the end product. 

Pressure relief valves play an important role in LNG piping systems. Any section of LNG piping that can trap LNG must have a pressure relief valve to prevent failure of that section of pipe should all the LNG vaporize. These pressure relief valves are similar to those used on LNG storage tanks. Spring-loaded valves that reseat following a reduction in pressure are preferred to those that do not and vent all the LNG in that line. Pressure relief valves should be protected from water accumulation to prevent freezing in the open position since the LNG vapor that is released will likely be very cold. 

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