Failure Modes & Effect Analysis

A Failure Mode and Effects Analysis (FMEA) is an in-depth review of the system design, systematic identification of all credible single point failures (SPFs), and evaluation of the effects of all credible SPFs on the system, interfaces, and surroundings. A FMEA should be prepared by an individual(s) that has the background, training and experience to understand operation of various components and combination of components within a system. WHA performs FMEAs prior to performing OHFRAs to determine the worst case conditions based on credible single point failures.

 

Examples of failures modes for consideration based on component type

Component TypeFailure Mode
Pressure RegulatorFail Open, Fail Closed, Oscillates, External Leakage, Fails to Vent
FilterClogs, Passes Contaminants
Relief Valve,
Burst Disc
External Leakage, Fail to Relieve, Fail Open
Check ValveFail Open, Fail Closed, External Leakage
Quick DisconnectFail to Separate, Separate Prematurely,
Leak Before/After Disconnect
Manual ValveFail Open, Fail Closed, External Leakage
PumpFail On, Fail Off
Flow MeterErroneous High Indication, Erroneous Low Indication
OrificeClog
Flex HoseExternal Leakage
Heat ExchangerExternal Leakage, Internal Leakage

 

WHA uses the following simple three column worksheet to document the FMEA for each component

Failure ModeEffectRecommendation