Table 4 Subsea manifold system FMECA.
From: Reliability analysis of subsea manifold system using FMECA and FFTA
No. | Failure mode | Causes of failure | Severity | Occurrence | Hazard level |
|---|---|---|---|---|---|
1 | RBD | Parts broken, mechanical failure | C2 | F2 | Low risk |
2 | COM | Control valve deformation | C2 | F3 | Medium-low risk |
Production medium isolation valve leakage | |||||
3 | DOP | Production medium isolation valve control failure, misalignment | C3 | F2 | Medium-low risk |
Working medium isolation valve control failure, misalignment | |||||
4 | ELP | Connector damaged, leaked, loose, material failure | C3 | F5 | High risk |
Hard pipe corrosion, leakage, mechanical failure | |||||
Block valve leak, material failure | |||||
Production medium isolation valve leakage, corrosion, material failure | |||||
5 | ELU | Production medium isolation valve damage, leakage, mechanical failure | C3 | F3 | Medium risk |
6 | FTC | Production medium isolation valve is blocked, leaked, stained and worn | C3 | F4 | Medium-high risk |
Working medium isolation valve control failure, mechanical failure | |||||
7 | FTF | Control valve is blocked and the hydraulic pressure is stuck | C3 | F2 | Medium-low risk |
8 | FTO | Production medium isolation valve blockage, damage, corrosion, external influence, leakage, hydraulic clamping | C3 | F3 | Medium risk |
Working medium isolation valve blocked, mechanical failure | |||||
9 | HIO | Control valve misalignment, control failure | C2 | F3 | Medium-low risk |
10 | INF | Insulation gap/alignment failure, fatigue failure, material failure | C2 | F3 | Medium-low risk |
11 | LCP | Control valve leakage, fatigue failure | C2 | F4 | Medium risk |
Production medium isolation valve leakage, material failure, hydraulic clamping | |||||
Working medium isolation valve is leaking and blocked | |||||
12 | OTH | Hydraulic coupler blocked, hydraulic clamping | C2 | F2 | Low risk |
Production medium isolation valve is leaking | |||||
13 | PLU | Hard tube blockage, mechanical failure | C3 | F3 | Medium risk |
Control valve is blocked or misaligned | |||||
Working medium isolation valve mechanical failure, blockage | |||||
14 | SPO | Operating medium isolation valve control failure, general external effects, material failure, mechanical failure, hybrid failure | C2 | F3 | Medium-low risk |
15 | STD | Looseness of protective structure, drag effect of trawl | C3 | F2 | Medium-low risk |
16 | ILP | Manifold module corrosion, mechanical failure | C2 | F2 | Low risk |
17 | ILU | Manifold module corrosion, mechanical failure | C2 | F2 | Low risk |
