Wood Group Engineering Services LLC-Abu DhabiRepair Report Date: 20/07/2011 Customer:PDO Oman Description:48 -600#Ball Valve Make::PCC Ser. Nos: 217815 & 217816 Qty:2 Off Tag Nos: 66-UZ-404 and 405 WGES Job No:AD8000701 & AD8000979 Inspection: After Initial stripping and inspection of the valve the following were the observations: 1. Increased Clearances between Body sealing area and the adaptor, 2. Large chamfer on body sealing area. 3..Wear on Ball Drive Slot. 4..Damaged Seat Inserts Work scope Carried Out. 1.Weld Repairs body sealing areasincluding rectification to reduce large chamfers 2.Final machine Sealing areas to achieve standard Body Clearances. 3. Rectification of Ball worn out drive slot.4 Removal of existing damaged Nylon inserts,manf. new, press fit and final machine to original spec. 5.Reassembly of valve using new adaptor O-ring 10mm and fire seal gland rope(as per existing) 6 Tested Valve and found body leaking at 90 Bar. 7.Valve stripped and re inspection carried out. Observation 1.Adaptor O ring groove foundtoo big for 10 mm dia. O-ring.

Re-assembly Reassembled the valve using 10mm dia. o-ring plus 1 additional Back up ring to reduce groove width. Valve tested found leaking again through bolt holes. Stripping and Reassembly carried out with 2 back up Ring. Valve tested and again found leaking at 90 bar through bolt holes. Further Investigation ,Meeting with PDO & Recommendation After joint meeting with PDO official and wood group, We understood from PDO that this valve had leakage on site through bolts holes. It was decided to install 11mm O-ring( instead of 10mm )and SS spiral wound Gasket griphited on body ) Reassembly and in-house test carried out at 150 bar, successfully, Customer witness inspection carried out complete valve .successful. Conclusion /Root Cause of failureAs there were many unknown factors ,either previous repairsby other company, or could be original Defect, as this valve had existing leakage through bolt holes as discussed in the meeting,As per our assessment the root cause of the failure is basically a design problem which require us to do necessary modifications rectify the problem as mentioned above. Result. Successful after modification.

Submitted By:F. X. Rebello.