This paper explores the influence of mission time on the PFDavg of an ERC final element assembly. The ERC Assembly consists of an Emergency Release Collar with or without a Controlled Closure Valve, and three solenoids that control the hydraulic pressure to the collar.
With the express goal of illustrating how a PFDavg in the SIL2 range can be achieved, the results are presented in the form of tables showing the mission time required to reach a PFDavg at 80% and 100% of the SIL2 minimum. Results for two distinct modeling approaches are considered.
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