3 TASNEE HighlightsEstablished in the 1985 , first Industrialization Joint-Stock Wholly Owned by Private Sector .Major Businesses : Petrochemicals, Titanium dioxide and downstream products and services.Fully integrated operations including project development and implementation, operations and marketing.Over 7,000 Employees in five continents.
7 CW GRP pipe failure incidents 72” CW supply header to PE/PPIncident in EC plant Process areaSW / CW Exchangers(Total No's: 23)76” CW supply header to EC100” CW header100” CWS header28” CW header3E-3713(RGH reactor Methanol condenser)#676” CW Return header from EC to CWR main header
8 Investigation & RCA for GRP pipe ruptures Investigation & RCA used Fishbone Diagram methodology and Fact Tree Analysis for finding the possible causes leading towards GRP pipe failures.Using Fish Bone Diagram the identified root causes are as follows:CategoryIdentified root causeOperationWater surge/hammeringCW users leakageProcessGas ingress into systemMaintenance & ReliabilityMaintenance & Inspection proceduresMaterialsLack of industrial QC procedures for GRP elements.DesignSupports for Pipe & Pump and Soil settlement issuesFlexibility of the system for load variationsGRP header dynamic compatibilityDegassing system compatibility
10 Factors for GRP pipe ruptures System Design Factors are recognized from Fact Tree AnalysisDeficiency in the Design of the existing CW networkSoil Settlement issues- Soil compaction & Proper back filling- Monitoring system for soil settlementSupport for GRP lines- Surge/Stress analysis to find the dynamic load variation in pipe network- Piping system flexibility to handle the dynamic loadsGas relieving system adequacy to release the gas/vapors entered into the CW system- Large amount of gases ingress into the CW system- Venting system is not sufficient at individual CW user side
11 RCA for CW GRP pipe rupture : Fact Tree Analysis
13 CW Expansion Drum Venting 10” vent open with nitrogen dilution24” manhole crack open24” Vent lineN2 lineWater MakeupVent line is dipped under water level. Gas removal is restricted20 mm siphon (vent) holeDegassing pipesCooling water return
14 Factors for GRP pipe ruptures People/Manpower/Skills are recognized from Fact Tree AnalysisPoor Workmanship Leading to GRP Line FailureGRP Workmanship skills during the project execution stage & maintenance time- Time & Capital cost constraints during project period- Availability of trained maintenance and inspection personnel for GRP workLack of compliance with GRP manufactures standard with Execution Contractors
15 RCA for CW GRP pipe rupture : Fact Tree Analysis
16 Factors for GRP pipe ruptures The following Process Factors are recognized.GRP is not the suitable application for two phase Flow serviceEffective monitoring tools for detecting gas ingress into CW systemThe following Policies/Procedures Factors are recognized.Availability of industrial standards with Reliability & Maintenance forGRP PipesLack of QC &QA procedures for GRP maintenance & inspection
17 RCA for CW GRP pipe rupture : Fact Tree Analysis
18 RCA for CW GRP pipe rupture : Fact Tree Analysis
19 Mitigation & Monitoring Measures GRP failure Mitigation Measures & System Monitoring points are recognized from investigation & RCA study for new and existing CW GRP systems .CW GRP System Design MeasuresProper design study (Surge & Stress analysis) to be performed & validated during project stage :To find the dynamic load variation in the GRP network as the analysis will identify the stress concentrated areas in the pipe network & for additional supports allocation.To have the system flexible enough to handle the dynamic loads.Soil Settlement issues shall be rectified for U/G GRP pipe system as continuous Soil settlement will allow the GRP pipes to settle further more than the allowable limit and put an additional stress on the GRP line branches and finally will lead to failures/ruptures. So, It is required to have:Adequate soil compaction based on the varying load bearing capacity of the Soil & Proper soil back filling.Continuous monitoring system for soil settlement is made available at the existing set up & the same has to be considered during design phase.CW system design has to be considered during project stage with the case of amount of gas ingress and continuous relieving of the same as GRP is not proven for two phase flow.
20 Mitigation & Monitoring Measures People/Manpower/Skills MeasuresEfficiency of GRP Workmanship skills enhancement :Consideration of Proper Time & Capital cost constraints during project period as it could have resulted into handing over the jobs to sub-contractors in executing the pipe installation work ending up with less efficiency.To have the availability of trained maintenance and inspection personnel for GRP repair work.To have the compliance with GRP manufactures standard with Execution Contractors for installation/maintenance job execution.Process & Operations MeasuresInstalling gas monitoring systems at the tactical locations of in CW network & at CW end-users as it will provide an early signal about the gas leakage and will help in troubleshooting exercise to isolate the particular end-user instead of doing the exercise for the whole network.Proper & immediate Operations response with safety required for mitigation and relieving of the ingress gas into CW GRP system for avoidance of rupture at weak joints of the pipe.
21 Mitigation & Monitoring Measures Policies/Procedures MeasuresStandards for maintenance and inspection procedures are to be made available for Plant existing system GRP repair works.QC &QA procedures shall be made available with Plant Reliability & Maintenance for GRP pipes inspection.CW network exchangers inspection plan shall be made available with Plant Reliability & Integrity team.
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