Pressure vessels and piping systems are designed, fabricated, and operated to ensure very high levels of structural integrity, because the consequences of structural failures can be severe.The purpose of these requirements is to maintain the mechanical integrity of pressure systems throughout their life. They cover installation, inspection, maintenance, and repair of all types of pressure systems. Pressure systems must be maintained according to a schedule appropriate to system type and the operating conditions. Maintenance types include:§Preventive, which is generally determined by the manufacturer. Break down, which is an opportunity for maintenance due to unforeseen equipment shutdown§Periodic, which is required maintenance as determined by manufacturer’s recommendation and/or SLAC policyThis part describes a number of incidents involving piping failure.