Safety cases length

The scale of such social issues is pnqwrtional to the length of time during which safety case information may need to be retrieved the "limitation period" inhoent in the Consuma Protection Act 1987 indicates that a safety case needs to be retained until at least 10 years after the supply of the last system using that case. 

Application of this procedure to inadvertently ignited safety valve discharges can involve a special problem. Certain combinations of pressure ratio and length of safety valve riser can result in choked flow, with a pressure discontinuity at the exit. The pressure of the jet then adjusts to atmospheric pressure in a system of shock waves or expansion waves over a distance of a few pipe diameters. These waves can affect the local mixing of the jet with the crosswind. Since the calculation procedure incorporates correlations for subsonic jets, it cannot be expected to be entirely accurate in this case. Nevertheless, since the wave system... 

Failure occurs when the component ceases to perform its required function. In the case of catastrophic failure, such as the rupture of a pipe or electrical breakdown of an insulator, this is obvious, but in many cases there is no such clear end of life. For example, is the end point when a small amount of environmental stress cracking has occurred, or when cracks have reached 5 mm in length Broadly, the definition of end point is that a property has reached a level at which safety, performance or market acceptance dictate that the component or product can no longer be used. 

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