REPORT ON ROOT CAUSE ANALYSIS OF VALVES SEAT LEAK WHILE SITE TESTING.

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1 REPORT ON ROOT CAUSE ANALYSIS OF VALVES SEAT LEAK WHILE SITE TESTING. REF EDRs: SITE-NCR-056-VENDOR L&T & SITE-NCR-061-VENDOR L&T Team Members: Hari K S Sr. DGM Head Quality Control. Suresh J Sr. DGM, Manufacturing. Abdul Shukkur M A DGM, Manufacturing. Gopalakrishnan S DGM QC Ramajeyam K - Manager, Quality Control. Vijayakumar J - Manager, Production. Ganesh Kumar S - Manager, Production. Sivasankaran C Manager Painting & Packing.

2 CONTENTS 1.0 Background 2.0 Preliminary Analysis & Interim Containment Action(s) 2.1 Preliminary Analysis 2.2 Correction 3.0 Root Cause Analysis 3.1 Problem Description 3.2 Cause and Effect Diagram 3.3 Significant Causes 3.4 Why-Why analysis 4.0 Corrective Action

3 1.0 Background: M/s SAUDI ARAMCO has reported seat leakages while site testing on L&T supplied Gate valves & Issued EDRs (02250-SITE-NCR-056-VENDOR L&T & SITE-NCR-061- VENDOR L&T) EDR Details: Valve Details: Valve Size 6" 2 Class Type of valve Gate Valve Gate Valve Body/Bonnet Material ASTM A216 Gr WCB ASTM A216 Gr WCB Total PO line item Qty. 05 Nos. 03 Nos Seat Leak Qty. 01 No. 01 No L&T Valves Sale Order / / /80 Line Item Customer Tecnicas reunidas Tecnicas reunidas Customer PO no Customer Line item no Tag no HVGB10A5013G2AG00AE1 HVGB10A5012E1AG00AE1 Valve Sl. Nos. dispatched for this PO line item 17C127444, 17C127445, 17C127446, 17C128212, 17C C136891, 17C136892, 17C136893

4 2 Preliminary Analysis & Interim Containment Action(s): 2.1 Preliminary Analysis: Preliminary analysis was carried out with Production, Quality Control, D e s i g n, P a i n t i n g & L o g i s t i c s t e a m to review the cause of failure while site testing. Inspection test plan specific to this order reviewed and found acceptable. Internal Valves test report specific to leak valves reviewed and found acceptable. Final Inspection Report (SCN) specific to these valve reviewed and found acceptable. TPI witness documents - Hydro offer list reviewed and found acceptable. PDI records & Photographs specific to this valves reviewed and found acceptable. Further investigation: Complaint reported valve internal records are completely verified and fulfilling all the quality requirements before packing. Also, in this leak reported valve line item, all valves are inspected by nominated agencies at L&T shop for PO line item & 2 out of three valves were witnessed by nominated agencies for PO line item before dispatch by visual, hydro, painting & packing. Valve Witnessed PO Line item Valve Serial No witnessed by TPIA & AOC 17C WCB Gate Valve C C C C WCB Gate Valve ( With Pressure relief hole) C C It is reported from site that valve has passed seat test on A side and failed to pass seat test on B side on WCB gate valve & continuous seat leak on WCB gate valve.

5 We infer that there is entrapment of foreign particles inside the flow bore area in valve which caused seat leak at site. 2.2 Correction: Jet cleaning with water is required in flow bore of valves to clear the foreign particles and valves require re- Seat test to find out whether leak is observed or not after Jet cleaning. 3.0 Root cause Analysis - RCA 3.1 Problem Description WHAT DESCRIPTION AREA What object has the defect? Valves DESCRIPTION DATA What is the defect? Seat leak on sealing face. WHERE Where specifically on the valve do you see the defect? Where geographically is the object observed? Seat sealing location. TR Jazan site WHEN First seen - By the customer? When did we make the part? When seen since? When is the observation seen in the valve- while Testing operation (i.e. when the valve is used)? Yes. Year First occurrence at TR jazan site During Site Testing. HOW BIG How many objects have noticed this observation?one How many/much observation(s) per object? One

6 3.2 CAUSE AND EFFECT DIAGRAM CAUSE AND EFFECT DIAGRAM DEFINE & VERIFY ROOT CAUSE METHODS/PROCESSES MACHINE Body /disc - Poor Machining & lapping process Excess clamping pressure Foreign particles intrusion during Serration Rework after Hydro test Un Trained Testers In correct disc machining & machine accuracy. Improper Cleaning of seat sealing interface PROBLEM STATEMENT Seat leakage observed during Site testing Un Trained Assemblers Damage on Body/ disc seat surface MAN MATERIALS

7 3.3 Significant Causes Seat Leak Sl. No CAUSES SIGNIFICANT / IN- SIGNIFICANT 1 Body /disc - Poor Machining & lapping INSIGNIFICANT 2 Foreign particles intrusion during Serration Rework after Hydro test INSIGNIFICANT 3 Excess clamping pressure INSIGNIFICANT 4 Incorrect disc machining & machine accuracy. INSIGNIFICANT 5 Un Trained Testers INSIGNIFICANT 6 Un Trained assemblers INSIGNIFICANT 7 Improper Cleaning of seat sealing interface SIGNIFICANT 8 Damage on Body/ disc seat surface INSIGNIFICANT 3.4 Why-Why Analysis Why? Seat Sealing interface is not clean Why? Intrusion of Foreign particles inside the valve Why? Seat sealing Interface cleanliness not checked at site. Root Cause: Valves are tested without proper cleaning of Seat sealing Interface at site.

8 4.0 Corrective action: 1. Awareness will be given for site test team on the Information Tag for the internal cleaning which was tied in all Valves after Final PDI inspection in L&T Valves. 2. Awareness given to the plant shop operatives to improve the valves protection after hydro testing. = End of Report =

REPORT ON ROOT CAUSE ANALYSIS ON VALVE SEAT LEAK OBSERVED AT SAUDI ARAMCO REROUTE PIPELINE IN RASTANURA AREA PROJECT

REPORT ON ROOT CAUSE ANALYSIS ON VALVE SEAT LEAK OBSERVED AT SAUDI ARAMCO REROUTE PIPELINE IN RASTANURA AREA PROJECT Team Members: Hari K S - Sr. DGM - Quality Control Sankar P Sr. DGM- Production Kandasaami