Safety equipment is a collection of safety related applications. Providing insight in how the failure rate, impact, demand and performance is for SIF. It also provides an overview of performed tests for the related equipment
Demands gives an overview over all configured SIF’s and the elements within each SIF. It counts and calculate (rates) for process, faults and test demands. The process demand rate is compared to the configured design rate and gives a status OK or Warning for each SIF.
There is also a Demand History section where historical demands for each SIF is presented. If logged in with sufficient user rights, the user can change a demand type if logged demand type is wrong to get correct statistics.
Failure Rate uses historical data and the original design parameters to calculate new suggested Failure Rate (λDU) for the various types of final element equipment, such as valves, circuit breakers and fire dampers.
The purpose of calculating new failure rate is to get indications as to whether the test interval for the equipment can be updated. The Failure Rate report shows the configured Safety Integrity Level parameters for each element type, and periodical statistical data calculated by the application. The statistical data are calculated from equipment operations over time on automatic operations, manual operations and trips/shutdowns. The calculation interval is configurable, but is typically 6 months or a year to obtain a solid statistical data basis. This will also provide good documentation for suggestions on changing the required test interval for each equipment type.
PFD (Probability for Failure on Demand) Calculator shows the impact of Failure Rate and test interval changes for all configured final element types. The user can insert different test interval values for each element type, and calculate what PFD this would give. There is also a Generic calculator, where the user can calculate the effect of different λDU together with different test interval values. The PFD calculator is used to show the impact of Failure Rate and test interval changes for all configured final element types.
Final Element provides an overview of operations and registered failure on safety final elements (safety barriers), such as number of faults, operations, partial strokes. This is a helpful tool for analyzing operational data, and separating random failures from systemic failures. It also utilizes both normal system operations and manual tests to create statistical data for each safety output element. This is the base data for calculating and documenting SIL levels, which is used among other applications like Failure Rate.
It provides info such as:
- Configured and measured activation times for the equipment, or travel times if the equipment is a valve.
- Only operations that include a full movement of the equipment are counted as successful operation to safe position.
- For valves with more than one solenoid, it distinguishes between operations on each individual solenoid.
- Possible to view the details of the operations for each tag.
Test Interval provides an overview of all test intervals for each item of safety equipment, together with the last registered test/operation date and calculated remaining time to next test. When a successful action on the equipment has been performed, the test interval is reset automatically. Both normal operations, shutdowns, trips, and manual tests such as individual equipment activations or controlled ESD tests are used to calculate if the equipment has been properly activated, which will count as an operation that can reset the test interval period.
- For safety valves, it handles individual test intervals for each solenoid, and only operations performed on respective solenoid can reset the test interval period.
- For valves with partial stroke test functionality, it distinguishes between partial stroke operations and complete valve movements on each solenoid.
- For initiators, it distinguishes between different tripp levels, so that each tripp level can be tested and documented individually.
Valve Stroke Test
Valve Stroke Test shows the latest status of the valve stroke test for all configured valves. It provides the latest results of the stroke test for each valve solenoid. It displays configured travel time from SAS and measures travel time on last test, together with temperature (typical outside) when test was performed. If logged in with sufficient user rights, the user can add comments on each valve stroke test. There is also a Valve Stroke Test History that shows the status for all tests performed on valves in a selected timespan. It is also a possible to view the details (events) for each stroke test.