Probability of Failure on Demand (PFD)
Reliability, as previously defined, is the probability a component or system will perform as designed. Like all probability values, reliability
Safety Instrumented System (SIS)
A Safety Instrumented System (SIS) is engineered to perform “specific control functions” to failsafe or maintain safe operation of a process when unacceptable or dangerous conditions occur.
Reliability of a Control System
Reliability (R) is the probability a component or system will perform as designed. Like all probability figures, reliability ranges in
Bathtub Curve
Failure rate tends to be constant during a component’s useful lifespan where the major cause of failure is random events
Control Valve Failure Rate Calculation
Suppose a control valve manufacturer produces a large number of valves, which are then sold to customers and used in
Transistor Failure Rate Calculation
Suppose a semiconductor manufacturer creates a microprocessor “chip” containing 2500000 transistors, each of which is virtually identical to the next
Failure rate and MTBF of Safety Instrumented Systems
In reliability engineering, it is important to be able to quantity the reliability (or conversely, the probability of failure) for
Applying Probability Laws to a Safety Instrumented System
The relatively simple concepts of AND and OR Boolean functions become surprisingly complicated when applying them to real-life measures of
Safety Instrumented System Probability
While the term “probability” may evoke images of imprecision, probability is in fact an exact mathematical concept: the ratio a
Process Safety and Instrumentation
Here we discuss about instrumentation related to industrial process safety. Instrumentation safety may be broadly divided into two categories: how
SIS Example : Nuclear Reactor Controls
Nuclear fission is a process by which the nuclei of specific types of atoms (most notably uranium-235 and plutonium-239) undergo