JOB PROCEDURE FOR WELDING AND WELDING CONTROL JOB PROCEDURE FOR WELDING AND WELDING CONTROL PROCEDURE NO: TEL/tkIS/NALCO/MECH/UNIT/JP/019, REV-00 NAME OF WORK MUD SETTLING, WASHING AND ASSOCIATED FACILITIES (PACKAGE –1.0 MTPA ALUMINIUM REFINERY AT DAMANJODI) OWNER NATIONAL ALUMINIUM COMPANY LIMITED CONSULTANT ThyssenKrupp Industrial Solutions(I) Pvt. Limited CONTRACTOR TUAMAN ENGINEERING LIMITED BOA N0 NBC/MMXP/REF/STRM5/CA0042/229 dated 02/05/2022 NBC/MMXP/REF/STRM5/CA0042/230 dated 02/05/2022 NAME OF WORK MUD SETTLING, WASHING AND ASSOCIATED FACILITIES (PACKAGE –1.0 MTPA ALUMINIUM REFINERY AT DAMANJODI) REV. DATE DESCRIPTION PREPARED BY TEL PROCEDURE NO: TEL/tkIS/NALCO/MECH/UNIT/JP/019, REV-0 CHECKED BY TEL Page 1 of 8 APPROVED BY TEL REVIEWED BY TKIS/NALCO APPROVED BY TKIS/NALCO JOB PROCEDURE FOR WELDING AND WELDING CONTROL TABLE OF CONTENTS 1.0 PURPOSE 3 2.0 SCOPE 3 3.0 REFERENCES 3 4.0 DEFINATION 3 5.0 PROCEDURE 3 5.1 Welding Procedure Qualification 5.2 Welder Qualification 5.1 Welder Performance 5.1 Welding Machine Maintenance 5.1 Material Inspection 5.1 Fit-Up 5.1 Welding Sequence 5.1 Preparation prior Welding 5.1 Inspection during Welding 5.1 Inspection after Welding 3 4 4 4 5 5 6 6 7 8 RECORD 8 6.0 PROCEDURE NO: TEL/tkIS/NALCO/MECH/UNIT/JP/019, REV-0 Page 2 of 8 JOB PROCEDURE FOR WELDING AND WELDING CONTROL 1.0 PURPOSE: This procedure establishes & defines the requirements of preparation of control of welding activities to ensure to all production weld are of good quality in accordance with governing code and project specification of tkIS/NALCO. 2.0 SCOPE This procedure covers all the stages of work before welding, which include selection of WPS, welder qualification, welding machine maintenance, material identification, welding sequence and inspection during and after. 3.0 REFERENCES API STANDARD 650 - Welded Tanks for Oil Storage ASME Sec IX - Welding and Brazing Qualification API 1104 - Welding of Pipelines and Related Facilities 4.0 DEFINATIONS RT - Radiography Testing UT - Ultrasonic Testing WPS - Welding Procedure Specification MPI - Magnetic Particle Inspection NDT - Non-Destructive Testing QA - Quality Assurance QC - Quality Control AFC - Approved for construction 5.0 PROCEDURE 5.1 WELDING PROCEDURE SPECIFICATIONS 5.1.1 Prior to fabrication, CONTRACTOR shall identify applicable WPS required under scope of their work. 5.1.2 The WPS shall be qualified in accordance with the governing code and project specification with corresponding PQR. 5.1.3 Proposed WPS shall be submitted to tkIS/NALCO for review and approval before commencement of qualification test. Qualification test shall be conducted in presence of tkIS/NALCO and the test piece shall be visually inspected and nondestructive test shall be done as per client specification. The accepted test piece shall be sent for mechanical test by PROCEDURE NO: TEL/tkIS/NALCO/MECH/UNIT/JP/019, REV-0 Page 3 of 8 JOB PROCEDURE FOR WELDING AND WELDING CONTROL independent approved third party lab. 5.1.4 A complete documentation of the welding qualification record, NDT reports and mechanical test results shall be compiled together with WPS submitted for tkIS/NALCO for endorsement. 5.1.5 The welding engineer shall issue an updated resister of all the approved WPS applicable to the work to the relevant department i.e. production, engineering etc. for information. 5.2 WELDING QUALIFICATION 5.2.1 Prior to fabrication, CONTRACTOR may submit names of the welders who are previously qualified with tkIS/NALCO or from other projects together with their performance record to tkIS/NALCO for consideration on acceptance without qualification test. 5.2.2 Those welders’ needs to be qualified shall undergo qualification test as per ASME Sex IX. 5.2.3 CONTRACTOR shall inform to tkIS/NALCO at least before 01 day prior to any welder qualification test. CONTRACTOR QA/QC shall monitor the welder during the qualification and check the welding parameters used by the welders. 5.2.4 The final acceptance of welder / welder operator’s qualification shall be by tkIS/NALCO. 5.3 WELDER PERFORMANCE 5.3.1 CONTRACTOR QA/QC Engineer shall compile a resister for all qualified welders / welding operators and their qualification. 5.3.2 The QA/QC Engineer shall develop and maintain a report of welder performance and submit to tkIS/NALCO on weekly basis. 5.3.4 Welders who are unable to maintain a good standard of workmanship or who have accumulated repair rate more than 5% shall be warned and counseled. If after the warning and counseling their performance rate have not improved they shall be demoted or removed from project site at the desecration of tkIS/NALCO. 5.3.5 Each qualified welder shall be given a welder identification number. The welder shall mark hid ID No. on weld by means of indelible crayon or metal marker adjacent to the weld. 5.4 WELDING MACHINE MAINTENANCE 5.4.1 Prior to all fabrication work the welding machine and ancillary equipment shall be checked and made good and safe for its purpose. 5.4.2 Periodical checking and maintenance work are essential to the safety, reliability and accuracy of the machine. 5.4.3 Calibration of all welding machine for the project shall be conducted before start of the work and calibration certificates shall be submitted to tkIS/NALCO. PROCEDURE NO: TEL/tkIS/NALCO/MECH/UNIT/JP/019, REV-0 Page 4 of 8 JOB PROCEDURE FOR WELDING AND WELDING CONTROL 5.5 MATERIAL INSPECTION 5.5.1 All material shall be inspected in accordance with latest approved AFC / Shop drawing, mill certificate and cutting plan to ensure correct material specification, dimension, cutting profile and free from any surface defect. 5.5.2 CONTRACTOR shall ensure the transferring the heat number is done prior to cutting. 5.5.3 Inspection and acceptance by QC Inspector and tkIS/NALCO representative are required prior to cutting of any material. 5.6 FIT-UP 5.6.1 All fit-up inspection shall be conducted by QC inspectors and when required shall be witnessed by tkIS/NALCO. 5.6.2 All joints shall be checked by approved drawing and welding procedure specifications. 5.6.3 Preparation of weld edge shall be by thermal cutting or machining. For thermal cutting the surface shall be ground to a smooth uniform surface. The edge preparation shall be visually checked for any lamination and defect at the cut and ground edges. Any lamination or defect observed shall be removed by grinding and check with MPI. 5.6.4 Design and tolerance of groove weld shall be in accordance with the approved WPS. 5.6.5 Tacking work shall be done by qualified welders and to be performed with the same qualified procedure as that will be used for fabrication welds. Consumables used for tacking shall be same as per qualified WPS. 5.6.6 Tack welds for structural joints shall be a minimum of 50 mm long. Tack welds shall be sufficiently and equally spaced to prevent the tack weld from cracking. These tack welds shall be cleaned by grinding before actual welding commences. 5.6.7 The alignment and dimension of the material to be welded shall be checked during fit-up inspection. 5.6.8 Surface to be welded shall be cleaned and free from oil, grease, water, loose scales, paint and any foreign materials. 5.6.9 All temporary attachment shall be cut from a good condition plates and shall match the adjoining members in terms of weldablity. PROCEDURE NO: TEL/tkIS/NALCO/MECH/UNIT/JP/019, REV-0 Page 5 of 8 JOB PROCEDURE FOR WELDING AND WELDING CONTROL 5.6.10 Temporary attachment shall not be removed by breaking, knocking or other means which will cause damage to the surface of the structure. 5.7 WELDING SEQUENCE 5.7.1 Where shrinkage and distortion is likely to affect the adequacy of the members or structure, welding sequence shall be developed to control distortion, warping, creeping and the build-up of excessive internal stresses in the structure. 5.7.2 The welding sequence shall be briefed to the welders / welding operators and displayed prominently the work area. 5.7.3 Welding engineer or supervisors shall supervise the welding of the assembly to ensure the planned sequences are followed. 5.7.4 Welding sequence shall include: I. WPS to be applied. II. Sequence of joint to be welded. III. Number and location of welders at each stage of assembly. IV. Tack welds, temporary attachments and spacers used in the assembly of components. V. Preheating of joints to be welded (If required). VI. PWHT (If required). 5.7.5 Avoid welding components at both ends simultaneously because this will cause the high stress in the component due to weld metal shrinkage when cooling. The high stress can cause distortion of components or crack in the weld joint. 5.8 PREPARTION PRIOR WELDING 5.8.1 All approved WPS shall be posted at site welding supervisors and welders reference. Welders shall be adhere to the welding parameters as specified in the related WPS. The welding supervisors shall ensure that the welders follow the parameters in the WPS. 5.8.2 Welding consumables to be used for welding shall be checked for the correct classification, type and size as per approved WPS. It must by dry and free from foreign material such as grease, oil, water and paint. 5.8.3 Preheating temperature shall be carried out by electrical resistance or with gas burner for carbon steel and shall be checked by means of thermocouple or templestick. The preheating PROCEDURE NO: TEL/tkIS/NALCO/MECH/UNIT/JP/019, REV-0 Page 6 of 8 JOB PROCEDURE FOR WELDING AND WELDING CONTROL temperature shall be established to a distance of at least 75 mm from the joint groove and through the wall thickness prior to welding. 5.8.4 Welder qualification shall be checked and his identification no. shall be written with permanent marker adjacent to the joints. 5.8.5 The welder (s) shall be briefed on the applicable WPS requirements i.e. ampere, voltage, travel speed, type and size of consumables, preheating etc. 5.8.6 Welding sequence shall be available at work area for reference. 5.9 INSPECTION DURING WELDING 5.9.1 Interpass temperatures and welding parameters shall be controlled during welding and in accordance with the approved WPS. Welding supervisor and QC Inspector shall check on the interpass temperature and welding parameters. 5.9.2 The maximum weave width shall not excess 3 times of electrode diameters. 5.9.3 Weld start and stop should be staggered by 50 mm of each weld pass of each weld layer. This is essential in order to avoid unnecessary defects and poor weld profiles which may require dressing and re-welding. 5.9.4 Weld progression in vertical and near vertical position shall be by uphill method. 5.9.5 Care must be taken when laying down welding torch to ensure that the electrodes ends do not comes in contact with plate surface. Any arc strikes shall be subjected to repair. 5.9.6 Rapid or abrupt cooling of weld shall be avoided. 5.9.7 Electrodes shall be kept in a heated quiver all the times. 5.10 INSPECTION AFTER WELDING 5.10.1 The following inspection shall be carried out after a welded component is completed. I. Weld size and reinforcement. II. Completeness of welds. III. Appearance of welds (such as weld profile, spatter etc.) IV. Geometrical and surface defects on weld such as underfilling, udercuts, overlaps, cracks, craters etc. V. Identification of weld and welder numbers. PROCEDURE NO: TEL/tkIS/NALCO/MECH/UNIT/JP/019, REV-0 Page 7 of 8 JOB PROCEDURE FOR WELDING AND WELDING CONTROL VI. Distortion of components. VII. Arc strike on parent metal. VIII. Dimension check. IX. Straightness check. X. NDE inspection. 5.10.2 For effective inspection, it is essential that the weld and adjacent surface is cleaned from slag, spatters, mill scales and oxides. 6.0 RECORD The following inspection reports shall be produced by CONTRACTORS. I. Fit-up Report II. NDE Reports i.e. MPI, DPI, UT, RT (whichever applicable) III. Weld visual reports IV. Dimensional reports All reports shall be verified by tkIS/NALCO representative and must be kept by CONTRACTORS for final documentation. PROCEDURE NO: TEL/tkIS/NALCO/MECH/UNIT/JP/019, REV-0 Page 8 of 8
