This paper makes comparison between ETT and DTT designs for the interface to a partial final element consisting of an Emergency Release Coupling (ERC) assembly and the effect that the interface voting architecture has on the PFDavg, spurious failure rate, and MTTFS of the final element. The impacts of both ETT and DTT solenoid designs are considered.
The results are presented in the form of tables that demonstrate the %SIL1, PFDavg, MTTFS, safe failure rate, and safe failure fraction (SFF) that can be achieved using various proof test coverages for each interface design.
Whitepapers in the Series:
→ Analysis of a Ball Valve / ERC Assembly
→ Analysis of Architectural Constraints Applied to an ERC Assembly
→ Comparison of ETT and DTT Interface Designs for an ERC Assembly