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Welding procedure specification
M.S.RogersM.S.Rogers T E C H N O L O G Y Copyright © 2003 TWI Ltd CSWIP Welder Training Weld Procedures M.S.RogersM.S.Rogers T E C H N O L O G Y Copyright © 2003 TWI Ltd Welding Procedures Welding Procedures (BS EN 288) (BS EN 288) M.S.RogersM.S.Rogers T E C H N O L O G Y Copyright © 2003 TWI Ltd Welding Procedures Welding Procedures Producing a welding procedure involves: Planning the tasks Collecting the data Writing a procedure for use of for trial Making a test welds Evaluating the results Approving the procedure Preparing the documentation M.S.RogersM.S.Rogers T E C H N O L O G Y Copyright © 2003 TWI Ltd In most codes reference is made to how the procedure are to be devised and whether approval of these procedures is required. The approach used for procedure approval depends on the code: Example codes: AWS D.1.1: Structural Steel Welding Code BS 2633: Class 1 welding of Steel Pipe Work API 1104: Welding of Pipelines BS 4515: Welding of Pipelines over 7 Bar Other codes may not specifically deal with the requirement of a procedure but may contain information that may be used in writing a weld procedure EN 1011Process of Arc Welding Steels Welding Procedures Welding Procedures M.S.RogersM.S.Rogers T E C H N O L O G Y Copyright © 2003 TWI Ltd Welding Procedures Welding Procedures Parent material • Type (Grouping) • Thickness • Diameter (Pipes) • Surface condition) Welding process • Type of process (MMA, MAG, TIG, SAW etc) • Equipment parameters • Amps, Volts, Travel speed Welding process • Type of process (MMA, MAG, TIG, SAW etc) • Equipment parameters • Amps, Volts, Travel speed Welding Consumables • Type of consumable/diameter of consumable • Brand/classification • Heat treatments/ storage Components of a welding procedure Components of a welding procedure M.S.RogersM.S.Rogers T E C H N O L O G Y Copyright © 2003 TWI Ltd Welding Procedures Welding Procedures Joint design • Edge preparation • Root gap, root face • Jigging and tacking • Type of baking Welding Position • Location, shop or site • Welding position e.g. 1G, 2G, 3G etc • Any weather precaution Welding Variables • Run sequences • Back gouging • Interpass temperatures Thermal heat treatments • Preheat, temps • Post weld heat treatments e.g. stress relieving M.S.RogersM.S.Rogers T E C H N O L O G Y Copyright © 2003 TWI Ltd Welding Procedures Welding Procedures When the data has been collected, the procedure must be validated by producing a test weld, weld procedure test (WPT). A number of standards provides information with regards to approving a procedure, but normally this will require the WPT to be tested by NDT and mechanical testing. The locations and tests required will be given in the applicable code or standard Most codes and standards provide a report format to record the results Approving the procedure: Approving the procedure: M.S.RogersM.S.Rogers T E C H N O L O G Y Copyright © 2003 TWI Ltd Welding Procedures Welding Procedures Examination and testing requirements of a WPT for procedure approval (BS EN 288) M.S.RogersM.S.Rogers T E C H N O L O G Y Copyright © 2003 TWI Ltd Welding Procedures Welding Procedures After the testing is completed and all the relevant results collated, the results need to be assessed in accordance with the relevant code/standard. The results are then generally recorded. pWPS: pWPS: Preliminary Welding Procedure Specification Before procedure approval. WPS WPS : : Welding Procedure Specification After procedure approval WPAR (WPQR): WPAR (WPQR): Welding Procedure Approval Record Welding procedure test record M.S.RogersM.S.Rogers T E C H N O L O G Y Copyright © 2003 TWI Ltd Welding Procedures Welding Procedures Once the welding procedure has been approved, If any essential variable is changed during production the WPS may require re-approval. Most codes/procedures dealing with procedure qualifications provide a list of what is an essential or non-essential variable. Object of a welding procedure test Object of a welding procedure test To give maximum confidence that the welds mechanical and metallurgical properties meet the requirements of the applicable code/specification. Each welding procedure will show a range to which the procedure is approved (extent of approval) If a customer queries the approval evidence can be supplied to prove its validity [...]... TECHNOLOGY Questions QU 1 State six essential variables in a welding procedure QU 2 What do you understand by the term extent of approval and give four examples QU 3 Describe what you understand by a welding procedure specification, A welding procedure approval record and a welder certificate QU 4 What is the reason for approving a welding procedure and a welder QU 5 Give three reasons why a welder...TECHNOLOGY Example: Welding Procedure Specification (WPS) Copyright © 2003 TWI Ltd M.S.Rogers TECHNOLOGY Welder Approvals (BS EN 287) Copyright © 2003 TWI Ltd M.S.Rogers TECHNOLOGY Welder Approval Numerous codes and standards deal with welder qualification, e.g BS EN 287 Once the content of the procedure is approved the next stage is to approve the welders to the approved procedure A welders test... identification number 2 Date of test and expiry date of certificate 3 Standard/code e.g BS EN 287 4 Test piece details 5 Welding process, welding parameters, amps, volts 6 Welding parameters, amps, volts 7 Consumables, flux type and filler classification details 8 Sketch of run sequence, welding positions 9 Joint configuration details 10 Material type qualified, pipe diameter etc 11 Test results, remarks... Welders Qualification Test (WQT) Object of a welding qualification test To give maximum confidence that the welder meets the requirements of the approved procedure (WPS) The test weld should be carried out on the same material and same conditions as for the site welds The welder who carries out the procedure qualification weld automatically qualify when the procedure qualifies Copyright © 2003 TWI... welders qualification test It is normal for a qualified inspectors usually from an independent body to witness the welding Under normal circumstances only one test weld per welder is permitted If the welder fails the test weld and the failure is not the fault of the welder e.g faulty welding equipment then a re-test would be permitted The testing of the test weld is done in accordance with the . pWPS: pWPS: Preliminary Welding Procedure Specification Before procedure approval. WPS WPS : : Welding Procedure Specification After procedure approval . TWI Ltd Welding Procedures Welding Procedures Producing a welding procedure involves: Planning the tasks Collecting the data Writing a procedure