MPI TEST .................................................................................................................................................... 9
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METHOD STATEMENT FOR EXECUTION OF PIPING TIE-IN TP -60
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PURPOSE The purpose of this document is to provide a detailed outline for preparation, cutting and welding of in-service lines for branch take-off related to piping tie-ins TP-60. Branch at TP-60 will provide connection for new flare line 10” -FL-9123-A31BN with existing flare line 12”-FL-5321-1D. Hot tapping technique shall be used to facilitate the Branch take-off on an operational line without plant shutdown. SCOPE OF WORK 1) Mobilize manpower 2) Mobilize equipment’s 3) Scaffold works 4) Arrangement of Pipe fitting 5) Pipe preparation 6) Welding of Split Tee (Hot tie-ins) 7) Complete Qty 1 off 10” class 150 vertical hot tap on to 12” existing piping TP60 by other party 8) Documentation ,QC and safety Coverage for welding activities 9) Dismantle scaffolds 10) Demobilize manpower, scaffolding materials and Equipment ’s DEFINITION 1) Company - Zakum Development Company (ZADCO) 2) Main Contractor - ABB SpA 3) Sub-Contractor(Hot Tap) - Unique Wellube (UW) 4) Sub-Contractor - Granite Construction Company 5)
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L/T Sub Contractor
REFERENCE ASME B31.3 API 2201 ASME B16.5 ASME B16.9 ASME B16.25 ASME Sec IX A3-400-P-0136 A0-440-50-0053_2 A1-400-P-0624
ABB Doc Ref.
Euro Mechanical Contracting(EMEC)
&
Electrical
Process piping Procedure for welding or Hot tapping on equipment on service
Pipe flanges and flanged fittings Butt welded fittings Butt welding Ends Boiler & Pressure vessel Code welding & brazing Tie-in List P&ID Condensate & Flare Interconnection Piping Arrangement And support Area A2
GCC Doc Ref
EMEC Doc. Ref
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Piping ISO Tie-ins (400-10”-FL-9123-A31BN) MS & Risk Assessment for Hot tap at site SQCP for piping ZADCO Piping material spec JSA for Piping
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Location The location of proposed scope of work is in Zirku Island at Plant 430/423
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Responsibilities 1) Project Manager a) He will be responsible for overall site management b) He will be in-charge for organizing the construction team c) He shall be responsible for all construction activities d) It is his responsibility to ensure that job is carried out as per the project specification, monitor the job quality, priorities and achieving the milestones of project schedule. e) Project Manager will be responsible to ensure that the requirements of this method statement are implemented. f) He will ensure that the work is executed in a safe manner 2) Project Engineer a) He will be responsible for supervision at site and ensuring implementation and adherence to project specifications, procedures and HSE policies. b) He shall provide technical support to the construction team c) He will ensure the latest IFC drawings and specifications are followed at work locations. d) He shall control all resources and ensure productivity. e) He shall report the progress of work and coordinate with project manager. 3) Foreman a) He shall be directly coordinating with project engineer b) He shall ensure that all site activities are performed in safe and responsible manner in accordance with HSE safety procedures and permit to work etc., c) He shall provide all technical support to the team and will be engaged in direct supervision at site d) He will ensure that the work is progressing in compliance with the established project schedule, project specification and standards. e) He shall report daily to project engineer regarding the daily progress and manpower utilization. ABB Doc Ref.
GCC Doc Ref
EMEC Doc. Ref
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METHOD STATEMENT FOR EXECUTION OF PIPING TIE-IN TP -60
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QC Engineer a) He shall be responsible verifying ,monitoring and recording , the compliance of all activities as per project specifications HSE Officer b) He shall be responsible for implementing HSE procedures and coordinating with the safety team. c) He shall ensure that all work activities are performed in safe manner d) He will be responsible for making site safety reports, tool box talks and trainings. e) It is his responsibility to check all the work location for any unsafe conditions and liaise with project engineer to resolve the issues. f) He shall coordinate with project manager and project engineer.
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Plant & Equipment’s Following are major equipment’s a) Crane 25 T - 1 no b) Trailer - 1 No c) Pickup 1 Ton - 1 no d) Forklift 3T - 1 no e) Diesel Welding Machine - 2 no f) Certified lifting gears g) Power tools h) Calibrated Gauges, valves and hoses
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Procedure A. General Preparations 1) Obtain a proper permit to work with all necessary approved documentations 2) Split Tee shall be in accordance to the design standards of ASME B31.3 and issued as free issue item. 3) Material upon receipt site shall be inspected through RFI 4) Materials and equipment’s required to execute the job shall be moved to location 5) Location on the existing pipe where the split tee has to be welded shall be identified, verified and approved by ABB/GCC 6) Erect proper scaffold platforms at required elevation to safely execute the job. 7) Arrange charged fire hose at the work location 8) Coating on the external surface of existing piping shall be carefully removed using power wire brush on the proposed area extending to 150mm all around ABB Doc Ref.
GCC Doc Ref
EMEC Doc. Ref
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10) 11) 12)
13) 14) 15) 16)
the fitting. The pipe surface shall be visually examined and ensure that no circumferential weld within 1m of proposed fitting length. Surface shall also be checked for defects like cracks, pitting, laminations etc. The proposed location shall not overlap with other welding. Overlapping welds have greater possibility of forming a crack. The exposed pipe shall be checked to ensure that the ovality is within the specified limits The pipe wall thickness shall be checked by means of UT and the thickness shall be obtained over complete circumference of the pipe. In case the thickness measured is less than 5mm at any locations over the pipe circumference covered by the fitting, such locations shall not be used for welding fittings. The Proposed location of pipe shall be supported by means of scaffold beam ladders to accommodate the mounting weight of hot tapping machine. Prepare the bevel ends of split tee and remove any rust formation from inside the portion. Welders shall be qualified for specific WPS Ensure all assessments are carried out before welding activities.
B. Fit-up of Split Tee 1) ABB engineering team to advise ZADCO Operations regarding the flow rate to be maintained during the welding process of Split Tee according to the previously documented UT report 2) Obtain proper permit to work 3) Coverage area of the fitting should be wiped clean with a cotton rag. 4) Tack the bottom half of the split tee into position 5) Tack the top half of the split tee (with the branch connection) into position. The tack points should be along the long seam. 6) Cut loose both ends of the split tee by grinding off the tacks. 7) The branch position will be verified by the QC inspector and the hot tap supervisor prior to start of welding. 8) Both the carrier pipe and the fitting shall be preheated according to minimum 150Deg c 9) Preheating shall be carried out using propane heating torch. Two torches shall be used on opposite side of joints. The temperature shall be maintained throughout the welding cycles. If any additional heating is required between weld passes then it shall be provided. 10) Welding shall be performed in compliance with the approved WPS. ABB Doc Ref.
GCC Doc Ref
EMEC Doc. Ref
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11) Sequence of welding shall be as shown in figure -1 12) Welding shall continue without interruption so as to be completed in one heat cycle. 13) Welding current, voltage and speed shall be continuously monitored during the welding. 14) Throughout the welding cycle minimum and maximum inter-pass temperature shall be checked and monitored with digital thermometers. C. Welding Joint no 1 & 2 15) The two halves of split tee branch connection shall be clamped together using chain blocks. A gap of 1.5mm will be maintained between pipe and end of fitting for proper penetration and fit-up. 16) If the wall thickness of pipe is less than 5mm and within range of thin to very thin (3mm to 5mm), a backing strip of 25x2mm will be tacked to one half of split tee prior to welding 17) To reduce the burn through and cracking, it is advisable to use (3/32”) low hydrogen welding electrodes. It will also reduce the area of heating and temperature penetration through the header pipe 18) Start welding simultaneously on both sides from the center of grove in opposite directions until 50% of long seam weld is achieved. Then the other half of the groove will be welded in opposite directions and allow the tee to cool down and reach the parent pipe temperature. 19) Start and stop of weld shall be grinded by power grinding. 20) After the root pass of longitudinal seam is completed, MPI & DP test will be carried out. 21) The complete weld shall be visually inspected and accepted prior to being allowed to cool to ambient temperature. 22) Post welding MPI will be carried out at ambient temperature after completion of Fillet weld. 23) The completed weld shall be examined by magnetic particle inspection after 24 hours. D. Welding Joint no 3 1)
Preheat the weld area on the carrier pipe and fitting to minimum 150oC extending 50 mm along the carrier pipe and 50 mm along the fitting.
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Weld shall be completed utilizing two welders working on opposite sides of the pipe. Stop/start points shall be grinded and overlapped by min. of 1 inch.
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Buttering layers shall be deposited onto the carrier pipe. The first run shall be deposited as close to the edge of the fitting but shall not impinge onto the fitting.
ABB Doc Ref.
GCC Doc Ref
EMEC Doc. Ref
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METHOD STATEMENT FOR EXECUTION OF PIPING TIE-IN TP -60
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Buttering layers shall be deposited with the welders working on opposite quadrant of the pipe circumference.
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Required fillet leg length and fitting to carrier pipe gap shall determine the number of buttering passes required.
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On completion of the buttering layers, the joint shall be visually inspected and accepted prior to being allowed to cool to ambient temperature. The completed buttering layers shall be examined by Dye Penetrant and Magnetic Particle Inspection.
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Any residue from the magnetic particle shall be removed by power wire buffing.
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Preheat weld to minimum temp of 150Deg C
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The first pass in the throat of fillet shall not be extended by the electrode run out length before being reinforced by the deposition of next run. This technique shall be used progressively around the joint until the throat of the fillet is sealed.
10) After the root of fillet joint, MPI + DP examination will be carried out. 11) In case of any welding interruption MPI examination will be carried out. 12) The weld can now be completed in blocks or by continuous runs 13) The weld shall be completed in one heat cycle. 14) The completed weld shall be visually inspected and accepted prior being allowed to cool to ambient temperature. 15) The complete weld shall be examined by magnetic particle inspection. 16) Weld No.4 shall not commence until weld no. 3 has cooled to ambient temperature E. Welding Joint no 4 1)
Preheat the weld area on the carrier pipe and fitting to minimum 150oC extending 50 mm along the carrier pipe and 50 mm along the fitting.
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The sequence of welding shall be similar as stated for Weld joint no-3. Welding shall proceed as per step 11.2 to 11.15
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After QC approval the Welded Split tee with flange shall be released for Hot tap procedure
F. Mounting of Hot Tap machine (Refer to Doc: SRVO01215-EP-001) G. Hot Tapping procedure (Refer to Doc: SRVO01215-EP-001) H. Demobilize 1) Complete all hot tap procedure and QC approvals prior to demob of manpower ABB Doc Ref.
GCC Doc Ref
EMEC Doc. Ref
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equipment and scaffold materials. 9. MPI Test 1) Final Magnetic Particle Inspection will be carried out on longitudinal as well as Fillet welds 24 hours after their completion 10. Pneumatic Test 1) Secure a proper PTW for the pneumatic pressure test 2) Ensure all the pressure test accessories are calibrated 3) Install blind flange on the flange and pressure test the assembly using nitrogen. 4) Increase the test pressure in 25% increments until the final test pressure is achieved. 5) The test is considered satisfactory only if there is no leak or pressure drop. 6) Maintain the assembly at the test pressure for a minimum duration of 15 minutes. 7) ABB/ZADCO to advise the pressure for testing. 11. ATTACHMENTS 1) TIE-IN LIST – A3-400-P-0136 (SHT 10) 2) ISO DWG 400-10”-FL-9123-A31BN (SHT 1OF 2) 3) PIPING ARRANGEMENT AND SUPPORT – A1-400-P-0624 4) PIPING & INSTRUMENT DIAGRAM-A0-440-50-0053_2 5) ULTRASONIC THICKNESS GAUGING REPORT – AD-053
