ASME RAM-2:2016 pdf free download – Reliability, Availability, and Maintainability Program Development Process for Existing Power Plants
evident: term used to describe events or failures that experiencedoperatingcrewsshouldbeexpectedtonotice. evident failure: a failure that is evident to experienced operating crews and staff (nonspecific to cause). Experienced staff should notice and report the failure, based on general experience with off-normal conditions and failure criteria. Knowing what symptoms operators will be able to see to identify a failure affects mitigation planningfor addressingthatpotential failure. Conversely, when failures are not evident, different mitigation strate- gies to manage those failures must be used. failure mechanism: the mode and cause of an equipment failure. generalized time parameter: a parameter that measures the passage of time and aging of a component, and which may be used as the basis for scheduled mainte- nance. Number of operations, mileage, rotations, tons moved, and gallons flowed are examples of generalized time parameters. incipient failure: preexisting, emerging, and developing, though not evident, condition whereby equipment is nearly ready to fail; a hidden failure that is presumed to have existed prior to its becoming evident. lifelimit:alimitthatensures thereworkorreplacetaskfor an aging component or part is performed prior to the componentorpartreachingitsendoflife.Seesafelifelimit. maintainability: the ability to access equipment, perform maintenance work, and return the equipment to opera- tion. Access to parts, spare parts, and supporttools; avail- ability of trained, skilled personnel; ability to preplan work; and flexibilty of work rules all affect equipment maintainability. Maintainability supports the perfor- mance of “on-condition” (condition-directed) mainte- nance on short notice. masterequipmentlist(MEL): anequipmentregistrylisting all installed plant equipment. partitioning: the process of conceptually separating a component into its constituent parts for further evalua- tion and to differentiate risk;
rounds: tasks performed atshortintervals byoperators to monitor areas and alarm conditions; these tasks may include routine alarm resets, equipment observations, and equipment realignments. Each round takes the operator on a path through a section of the plant to monitor local conditions. routes: repetitive work performed on many different applicationsofthesamecomponentbyaskilledtechnician or mechanic in the same way. Repetitive calibrations, for example, may be placed into one route. safe life limit: a limit that ensures an aging safety-critical componentor partprovides uninterrupted service before reaching its end of life, or is replaced before reaching its minimum age limit. A safe life limit virtually guarantees items with directsafetyriskneverageoutbefore arework or replace task. scheduled maintenance: planned maintenance tasks, including condition assessments, scheduled based upon a generalized time parameter. Equipment asset manage- ment scheduling systems (EAMS) primarily generate scheduled maintenance work orders; operator rounds software installed on personal digital assistants (PDAs) controls rounds. Operator distributed control system (DCS) screen sampling points on visual control screen displays are equivalent to EAMS work orders for operators. secondarycomponent: a componentoutside the boundary oftheprimarycomponent; aseparatecomponentfromthe primary component of consideration. secondary failure: failure of a secondary component; a failure outside the primary component’s boundary, caused by a primary component failure. A secondary failure is external to the primary component, caused by the primary component, and therefore uncontrollable within the secondary component’s boundary. Examples include secondary failures caused by fires, load falls from hoists or cranes, and missiles created from disinte- grating rotating parts. No amount of scheduled mainte- nance on a primary component can eliminate the effects of external secondary component failures.