Research Article

Risk Identification and Quantitative Evaluation Method for Asset Integrity Management of Offshore Platform Equipment and Facilities

Table 6

SFMECA worksheet for the MLMS of the truss crane (SN: serial number; FU: function; FM: failure mode; FMT: failure mode type; FC: failure cause; FD: failure detection; FP: failure probability; FS: failure severity; FD: failure detectability; SE: security effect; EE: environmental effect; ECE: economic cost effect; MCE: maintenance cost effect; RPN: risk priority number; SR: safety risk; ER: environmental risk; ECR: economic cost risks; MCR: maintenance cost risk; CREV: comprehensive risk equivalent value; CRPN: comprehensive risk priority number; RMM: risk mitigation measures).

Item descriptionFailure mode analysisFailure effect analysisFailure risk analysis

CRANE01020404Winding steel wireAbrasionObvious potential typeNatural wear of long twisted wire rope3-7 yearsEasily detectedNo harmSlight influence¥0.1∼1million¥0.1∼0.5million28211171166416If it does not affect the use, there is no need for maintenance
CrackleObvious potential typeMaterial defects (especially castings) or welding defects constitute the cause of cracks and develop into cracks3-7 yearsNormally detectedNo harmSlight influence¥0.1∼1million¥0.1∼0.5million196225904910Surfacing welding after punching

CRANE01020405Speed down and increase the output torqueTransmission failureObvious sudden typeBond damage and planetary fracture0.5-2 yearsEasily detectedIntermediate injuryLocal influence¥0.1∼1million¥0.1∼0.5million21333317762Check whether the gearbox has any abnormal phenomena such as fever, vibration, oil leakage, and abnormal noise
VibrationObvious sudden typeBearing frame and stagnation0.5-2 yearsEasily detectedIntermediate injuryLocal influence¥0.1∼1million¥0.1∼0.5million21333317762Disintegration examination
Abnormal soundObvious sudden typeGear breakage, bearing falling, lack of lubrication, and severe wear on tooth surfaces>0.5 yearsEasily detectedNo harmMinor pollution¥20∼100 thousand<¥50 thousand17310154000011Check the oil level of the reducer, change the gear oil, and check the oil particle situation; check the fastener every 500 hours if necessary; torque wrench is fixed

CRANE01020406Stop moving and stay at restThe breaks cannot openObvious sudden typeOverall aging failure0.5-2 yearsDirectly detectedIntermediate injurySlight influence¥0.1∼1million¥50∼100 thousand16231717460820Dismantling and repairing once a year
Great impact on brakingObvious typeFriction strip wear out of limit (beyond the range of self-compensation)0.5-2 yearsEasily detectedNo harmSlight influence⩽¥20 thousand<¥50 thousand2172117409623Replace the piston seal every 500 hours; replace all springs every 3000 hours
Insufficient power, leading to a declineObvious potential typeBrake oil or cylinder block0.5-2 yearsEasily detectedIntermediate injurySlight influence¥0.1∼1million¥50∼100 thousand2738737285It is recommended to change the form of the brake

CRANE010205Lift wire ropeAbrasionObvious potential typeNatural wear0.5-2 yearsEasily detectedNo harmSlight influence⩽¥20 thousand<¥50 thousand2172117409623Check the degree of wear per month

CRANE010206Prevent the rope from jumping out of the pulley grooveDeformationObvious potential typeImproper operation0.5-2 yearsDirectly detectedIntermediate injurySlight influence¥20∼100 thousand<¥50 thousand16232129153627Check state at any time

CRANE010207Transfer pulling forceBroken wireObvious potential typeBroken wires due to wear; rust and broken wires due to lack of daily oil and maintenance3-7 yearsDirectly detectedIntermediate injurySlight influence¥0.1∼1million¥0.1∼0.5million19292016218726Daily inspection, pay attention to check the steel rope that is subjected to the impact load, the steel rope section that often produces friction with the roller and pulley frame, and the steel rope section which can easily cause fatigue damage repeatedly through the pulley
RustObvious potential typeCorrosion broken wire resulting from the lack of daily oil maintenance0.5-2 yearsDirectly detectedPrimary injurySlight influence¥20∼100 thousand¥0.5∼5million2123218409623Add 1 protective lubricant a month
AbrasionObvious potential typeThe steel rope is pulled up, resulting in natural wear and deterioration of lubrication condition0.5-2 yearsEasily detectedPrimary injurySlight influence¥20∼100 thousand¥0.5∼5million87121655369Check the diameter of the wire rope with vernier caliper. If it is found that the diameter has been reduced by more than 10%, it should be replaced. For frequent use of cranes, there should exist mandatory replacement of wire rope every 3 years

CRANE010208Transfer the force and change the direction of the forceSlots wearObvious potential typeRepeated winding work in the work, natural wear; rope angle is too large and will cause severe wear and tear0.5-2 yearsDirectly detectedPrimary injurySlight influence¥0.1∼1million¥0.1∼0.5million21231712460820Replacement of pulley when the wear is overlimited
Local rupture of the pulleyObvious sudden typeThe gap between bearing and bearing room is too large0.5-2 yearsDirectly detectedPrimary injurySlight influence¥0.1∼1million¥0.1∼0.5million21231712460820One decomposition check every two years
Bearing rash or stagnationObvious sudden typePoor lubrication; to reach the life span of bearing0.5-2 yearsEasily detectedPrimary injurySlight influence¥0.1∼1million¥0.1∼0.5million8733737285Add lubricating grease and replace the bearings regularly

CRANE01030101Loading cargo carrying capacityHook twistObvious potential typeHook deformation: open opening, distortion0.5-2 yearsEasily detectedIntermediate injurySlight influence¥0.1∼1million¥50∼100 thousand2738737285The dangerous section area should be reduced by 10%, which should be scrapped. The opening will increase by 15% or the distortion will reach 10 degrees
Hook wearObvious potential typeThe main hook's dangerous section has been rubbed by the wire rope for a long time, and there is a deep groove0.5-2 yearsEasily detectedIntermediate injurySlight influence¥0.1∼1million¥50∼100 thousand2738737285Nondestructive testing of hook surface
A crack in the hookObvious potential typeMisuse0.5-2 yearsNormally detectedIntermediate injurySlight influence¥0.1∼1million¥50∼100 thousand14133732481Visual inspection of the hook before each use

CRANE01030102Connection and fixationBolt breaking; thread slippingObvious potential typeThe transition tightened, causing thread slipping and even breaking0.5-2 yearsDirectly detectedPrimary injurySlight influence⩽¥20 thousand<¥50 thousand2123292851229Use torque wrench to tighten rope nut
Corrosion failureObvious potential typeExternal environment0.5-2 yearsEasily detectedPrimary injurySlight influence⩽¥20 thousand<¥50 thousand872117819217Strengthen rust prevention and maintenance; check once a month

CRANE01030103Prevent decouplingThe opening of the hook cannot be completely coveredObvious potential typeUse long time to deform0.5-2 yearsEasily detectedPrimary injurySlight influence⩽¥20 thousand<¥50 thousand872117819217Replace the spring and pin, and check the condition every time the rope is hung
DistortionObvious sudden typeExternal force deformation0.5-2 yearsEasily detectedPrimary injurySlight influence⩽¥20 thousand<¥50 thousand872117819217Operation specification; check the state every time the rope is hung

CRANE01030104Connecting driveAbrasionObvious potential typeThe fatigue damage of the wheel body or the impacting defect on the edge of the wheel0.5-2 yearsEasily detectedPrimary injurySlight influence¥20∼100 thousand<¥50 thousand8712171638412Replacement of pulley after partial crushing; standard assembly during failure maintenance
Inflexible rotationObvious typeThe damage of the pulley bearing; the wear and tear between the ropes0.5-2 yearsEasily detectedPrimary injurySlight influence¥20∼100 thousand<¥50 thousand8712171638412Lubricate the pulley bearing regularly; check the deflection angle of the wire rope in and out of the pulley

CRANE01030105Circumferential rotationHook rotation is not flexibleObvious typeLack of lubrication or dust particles enter, resulting in early wear and tear of bearings and broken raceway breakage0.5-2 yearsEasily detectedPrimary injurySlight influence¥20∼100 thousand<¥50 thousand8712171638412Regular refuel lubrication for hook bearing
The axial location of the hook is ineffective and the axial movement is largeObvious sudden typeBearing wear caused by impact load0.5-2 yearsNormally detectedPrimary injurySlight influence¥20∼100 thousand<¥50 thousand24312829444Strengthen daily inspection and remove inspection if necessary
The hook fell off because of the damage of the bearingObvious sudden typeThe lifespan of the hook bearing has reached its service life0.5-2 yearsEasily detectedPrimary injurySlight influence¥20∼100 thousand<¥50 thousand8712171638412Replace

CRANE01030106Fixed hook and pulleyAbrasionObvious potential typeLoosening of shaft end positioning component3-7 yearsEasily detectedNo injurySlight influence⩽¥20 thousand<¥50 thousand28212827129628Check lock block and lock nut for each class