Redundant instrumentation

Maintenance/ reliability engineering The QRA team will need information about process configurations during maintenance activities and historic data on equipment performance. For example, how often are the instruments calibrated, does the same person calibrate redundant instruments, and how often do the pumps require repair QRA results are always more accurate if based on actual plant data, and maintenance/testing policies can make an order of magnitude difference in the calculations. Expect to commit about 1 staff-week per month over the life of the project. 

Preferentially, instrumentation should exist to indicate, control, and alarm COPs at the N-E-L. Controls should be established to assure that these requirements can be met if the instrumentation fails, Consideration should be given to fail safe and/or redundant instrumentation. On-stream analyzers should be considered for COPs measured by laboratory analyses. 

The pipeline is usually buried to a depth of 2 m (6 ft) to minimize freezing concerns. The line should be equipped with extensive redundant instrumentation to ensure complete safety and integrity of the system. 

As the product moves from phase II into phase III, the number of seemingly redundant instruments should decline as the obvious choice, or best guess should rise to the top. If the goal of phase III studies is to file an NDA or gain regulatory approval, the studies may not be appropriately designed to capture the additional information deemed necessary for the product s success. In some cases, separate pharmacoeconomic studies may be needed prior to marketing. 

Selective control loops covers a large number of diversified selective control systems for protection of equipment, auctioneering, redundant instrumentation, variable structuring, and so on. 

Many findings suggested installation of redundant instrumentation. Consideration should be given to the use of Safety Instrumented Systems across the facility. 

Sometimes the hardware fault tolerance is confused with redimdancy. They are not necessarily the same thing. Sometimes redundant instruments are used to maintain process operation, not to perform the safety function. In those cases, redundancy is not the same as hardware... 

Key contributors to the unavailability are the failures of instruments TE2, TSH2, and TSHH2. An introduction of redundant instrumentation would reduce the expected value of the time averaged unavailability of the system to 2.1 X 10 . ... 

The reliability of SSCs may be degraded by human induced faults (for example, calibration of redundant instruments on the same day by the same individual may introduce similar errors into both components and thus increase the potential for common cause failure). The frequency of such faults may be reduced, for example, by establishing detailed procedures. 

Should an oil leak occur, redundant instrumentation will alert the operator to shut down the reactor coolant pump motor assembly and thereby avoid bearing damage. 

The operation of the SCS is controlled and monitored through the use of dedicated redundant instrumentation which... 

Traditional design based on multiple redundant instrumentation chaimels with a voting arrangement, as commonly used in analog applications, has benefits for the hardware of computer systems. However, this type of redundancy does not prevent a failure of the system due to common cause faults in hardware and software design that could lead to impairment of all redundant chaimels. 

The damage of the not physically separated redundant instrument sensing lines caused by an external or internal hazard, in some cases, may disable the functioning of reactor protection system. 

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