risk based inspection and maintenance in central eastern ... · risk based inspection and ... the...

Bay Zoltán Foundation for Applied ResearchInstitute for Logistics and Productions Systems BAY-LOGI

Risk Based Inspection and Maintenance in Central Eastern Europe - Experience at the Hungarian Oil- and

Gas Company

Dr. Gyöngyvér B. Lenkey(BAY-LOGI, Hungary)


Event based

Timebased

Conditionbased

Development of Development of maintenancemaintenance

strategiesstrategies

Reliabilitybased

Risk based

1950 1960 1980 1990 1995


Risk matrix – modification of riskConsequence of failure

Prob

abili

ty o

f fai

lure


RBI application trend in Europe

RBI is approved

RBI is under way

RBI is not approved

At MOL – first time in Hungary!

Slovnaft (SK) isgoing to implement

as well!


Basic objectives of the MOL project:

Condition-monitoring System for Pressurised Equipment

To reduce the number and length of the unplanned shut-downs,To increase the ratio of the planned maintenance work,To extend the shut-down periods,To provide fast and accurate access to system data for development, inspection and maintenance tasks,To optimise (minimise) the maintenance costs taking into account the expected level of system reliability.To implement the system for more than 50 units!!


InernationalInernational cconsortionsortiumumBAY-LOGI Bay Zoltán Foundation

Bureau Veritas France

R-Tech Germany

Facility Manager Ltd. Hungary

K-ép Stúdió Hungary

AGMI Plc.- Mat. Testing Lab Hungary


Basic technical functions of the MOL System: defined by the

maintenance strategy of MOLInspection planning on the basis of RBI(Risk Based Inspection) strategy. The RBI methodology is based on API 581standard.Maintenance program planning based on RCM (Reliability Centered Maintenance) strategy.


Structure of the Condition-Monitoring IT System

EXPERT SYSTEM SHELL

CADMATIC softwarer: - 2D and 3D

RCM database

software

RBI software

(API)

- Level I. - Level II. - Level III.

Existing MOL systems

(SAP, FIR)

User: MOL

Data exchange (e.g.. XML, Excel, Access)

DATABASE

Additional expert system

modules


DatabaseWEBPLM software:

Equipment-Inspection–Documents:– Unit– Equipment– Sub-equipment– Safety valves– Inspected piping– Inspection location identification– Material and other specific data– Inspection plans and results– Drawings, P&ID, PFD– Paper based documentation

(digitised)– RBI and RCM analyses results

and expert reports


3D model


RBI analysis RCM analysis

Qualitative an.(Level I):

- Unit based- Equipment based

Selected items

Failure mechanisms and effect analysis (FMEA)

Failure classification

Failure characteristic analysis (FCA)Inspection

program

Maintenance strategy selection

Level II Level III

Auxiliary functions (moduls)

Preparation of inspection plans

Trends

Query, riports

Identification of new failure

mechanisms

Corrosion defect assessment

Crack-like defect assessment

Failure case database

WEBPLM- database

Expert system

database

Expert system/WEBPLM

database

Expert system/WEBPLM database

WEBPLM- database

Expert system/WEBPLM database

Expert system

database

Expert system

database

Structure of the Expert System


Inspection planningand evaluation

Selection ofequipment

RBI analyses(Level I, II or/and III)

Inspection plans(inspection locations, selection of

inspection methods)

Issuing inspectioninstructions

Performing inspections,uploading inspection data

Documentation andevaluation of inspections

R-Tech software,RB.eye software

WEBPLM

WEBPLM

WEBPLM

WEBPLM


RBI analysis

Analysis levels:– Level I: qualitative:

• Few input data• Based mainly on expert judgement (qualitative classification)• Mainly for selecting critical equipment, ranking of equipment

– Level II: semi-quantitative analysis: • More input data, but partly not accurate numbers (intervals)• Expert knowledge, judgement is needed

– Level III: detailed quantitative analysis:• Accurate data, many input data • More automatism, more modelled failure mechanisms (mainly

corrosion)


Qualitative risk analysis for each equipment and inspected piping:

Risk matrix-Comparison of units

Unit-1 Unit-2


Process of risk analysis and inspection planoptimization

Quantitative analysis

Data collection

Risk calculation

Inspection data analysis

Equipment analysis and breakdown

Acceptable risk?

Acceptability criteria

Process data

Process data

Inspection data

Inspection data

Material data

Material data

General data

General data

Process analysis

Damage mechanism evaluation

Inspection history,

initial insp. strategy

Inspection data

analysis

Risk calculationData input

Inspection strategy

Yes:Valid inspection strategy

No:Modify inspection parameters / optimization


Analysis of inspection history –risk calculation before the inspection

Risk matrix


Evaluation of future risk –without inspection

Risk levelchanging w

ith time


Inspection program definition –future risk can be decreased

Effect of inspection

programon risk level


Comparison of unitsRes ults o f quantitative RBI analys is

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Unit1 Unit2 Unit3 Unit4 Unit5

Units

LowMediumMedium-highHigh


Comparison of analysis levelsLevel III.

(for selected equipment)Level I.

5 16 1 - 2.86%

4 5 22, 24 15 4 - 11.43%

3 32, 4 3 10, 12, 14, 18, 26, 20

7, 29 11 - 31.43%

2 8, 28, 30 9, 11, 17 1, 6, 2, 13, 25, 19, 27, 21, 23

15 - 42.86%

L I K E L I H O O D

1 31, 33, 34, 35 4 - 11.43%

A B C D E

2 - 5.71% 1 - 2.86% 6 - 17.14% 11 - 31.43% 15 - 42.86% 35

C O N S E Q U E N C E S


Preparation of inspection plans -WEBPLM

MOL Rt. TDK Finomítás, Százhalombatta 174 jelű HDS üzem; 100-as blokk Vizsgálati terv

Készítette:

Tóth László

Készült:

2004. 05. 18.

W-105.2 jelű Cirkulációs gáz utóhűtő Gyári szám: 34767 Gyártó vállalat: IAB Leipzig Gyártás éve: 1993 Veszélyességi osztály: ...

A k é s z ü l é k a d a t a i köpenytér csőtér

Tervezési nyomás [bar] 89 5 Engedélyezési nyomás [bar] … …

Üzemi nyomás [bar] 71 3 Tervezési hőmérséklet [°C] 120 50

Üzemi hőmérséklet [°C] 46 45 Térfogat [m3] 5.20 …

Közeg Cirkulációs gáz+könnyű szénhidrogén (bázikus)

Víz

Anyagminőség St. 355 St 37.4

3400

8890

O1620

P2BP3B

P1BP2AP4BP3A

P1AP4A

P7B

P8B

P7A

P8A

P6AP8A

P1AP4A

P5B

P6BP5A

P6A

P1BP2A

P3B P2B

P4BP8B

P7B

P3AP7A

P8AP4A P1A

Felülvizsgálati helyek és módszerek

Szerkezeti elem Mérési hely Mérési eljárás

Köpeny A, B, C, D TT1 Csonkok (P1A,P1B, P2A, P2B) A, B, C, D TT Készülék belső varratoldalon Varrat találkozások 150-150 mm, + az

edény közepén 300 mm-es hosszban MT

2 kijelölt helyen ST2 Csövek 20 % ET Belső felület VT

1 A belső felület szemrevételezéses vizsgálata (VT) alapján kijelölve. A kijelölt TT mérési helyekre a külső felületen mérési helyeket lehet szükségszerűen kialakítani. 2 Szemrevételezéses vizsgálat (VT) alapján kijelölve azon helyeken (min 2db.), ahol érzékelhető lokális belső korrózió indult meg. A kijelölt ST mérési helyeket fel kell tüntetni a külső felületen.

Preparation ofinspection plans


Evaluation of inspection results, documentation

Corrosion trend

Assessment of corrosion defects


Planning other maintenance tasks - RCM

Reliability Centered Maintenance (RCM) is a logical, systematic decision making process for defining optimum maintenance tasks:– An auxiliary method to RBI, since both considers the

probability and the consequence of a possible failure. – Evaluation of the failure probability is based on failure

statistics. – Evaluation of consequences is based on expert judgement. – The result of the evaluation is obtained by the decision of an

expert team, using a systematic analysis. – It is used typically for those functions that are not covered

by RBI and related NOT to containment and transport(e.g. reactors, furnaces, fin-fan coolers, heat-exchangers)


Number of RCM analysis in the pilot phase

Unit Number of

RCM analysis

Number of identified functions

Number of possible failure

modes

Number of failure modes

covered by RBI

Number of failure modes related to

the functional failure of the

control system

Number of failure modes related to

the failure of other equipment

Unit1 2 5 13 6 0 2 Unit2 13 30 96 19 17 30 Total: 15 35 109 25 17 32

Many failure modes are related not to the equipment itself, but to the instrumentation (which was not subject of the project)

Importance:– operational experiences can be documented and stored– maintenance tasks can be optimised and aligned

Detailed RCM is very time consuming ⇒ needed to use a simplifiedRCM (based on classification of equipment and failure modes)


Some initial experiencesThe shutdown period is in many cases determined by the technology, not by the inspection need (e.g. fouling of heat exchangers)Significant part of the overhaul cost is related to the opening up of the equipment – but it can be necessary due to technological reasons (e.g. need to clean heat exchangers’ tubes in every 4 years)Economical benefit (it is difficult to assess after that short period) – main achievements so far: to reduce slightly the number of unnecessary inspections (e.g. UTFor less critical units the possibility of the extension of the shutdown period is realistic


Main benifits – so far To collect and update the equipment dataAll the data and documents of the equipment and piping are collected and stored in a structured database – data availability for many peopleTo document the state and the possible failure mechanisms of equipment in a reproducible wayThe whole inspection planning process is more transparentOptimisation of the inspection efforts – e.g. to reduce the extent of unnecessary UT


SummaryAt MOL Plc. the RBI methodology has been implemented first time in HungaryA complex system has been developed with which: – Economical condition-monitoring can be realised, – Up-to-date information can be acquired,– Supports the maintenance-inspection activity and their cost

optimisation,– Which can be adapted to other industrial sectors (power,

chemical, pharmaceutical, etc. – considering the results of the RIMAP EU project – CEN Workshop Agreement!)