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  Welding Procedure Specification- WPS This document details, how to qualify a welding procedure specification-wps for weld metal overlay / cladding / surfacing , for both corrosion resistance overlay and wear resistance overlay welding. The reference standard selected for the purpose of qualification of cladding procedure and welder qualification is ASME Boiler and Pressure Vessel Code (BPVC) section IX. Step by step procedure for WPS preparation: Select the sample size (thickness of base metal) Prepare the test sample Weld the overlay / cladding over the test sample with appropriate filler metal Carry out the testings on the weld overlay as mentioned in the standard, Non Destructive Testing ( NDT ) & Mechanical Testing Prepare the Procedure qualification record ( PQR ) Prepare the Welding Procedure Specification ( WPS ) with ranges qualified for production Welder Qualification For the welder performed the PQR qualification test prepare the Welder certificate For additional welder

  How to interpret Acceptance Criteria for Ultrasonic Testing as per AWS D1.1 The Requirements of Ultrasonic Flaw detector equipment as per AWS D1.1 Structural Steel Welding code is given below: Equipment: The ultrasonic equipment’s shall be pulse echo type ‘A’ scan suitable for use with transducers oscillating at frequencies between  1&6 MHz. The equipment shall have valid calibration certificate .The test  equipment shall have a calibrated gain control adjustable in discrete 1 or 2 Db steps over a range of at least 60Db. Probe: Transducers/ search units with following characteristics shall be used.              Angle beam :  70° ,60°,45° (within plus minus 2°).              Crystal Size:   Crystal size shall be square or rectangular in shape and may vary from 5/8 inch to 1 inch (15mm to 25mm) in width and from 5/8 inch to 13/16 inch (15mm to 20mm) in height. The maximum width to height ratio shall be 1.2 to 1.0 and the minimum width to height ratio shall be 1.0 to 1.0. Frequency

  TASKS DURING WELDING OPERATIONS Welding inspection during welding operations should include all the audit parameters to verify that the welding is performed to the procedures. Such tasks may include the following: Quality Assurance Establish a quality assurance and quality control team with the welding organization. Quality control items to assess: Welder is responsible for quality craftsmanship of weldments. Welder meets qualification requirements Welder understands welding procedure and requirements for the work. Special training and mock-up weldments performed if required. Welder understands the inspection hold-points. Potential inspector actions: Review welder performance with welding organization as below Welding Parameters and Techniques Confirm welding parameters and techniques are supported by the WPS and WPQ. Quality control items to assess: 1.Essential variables are being met during welding. Filler material, fluxes, and inert gas composition/flow rate. Purge technique, flow

 Non relevant Ultrasonic Indications can usually be identified as one of the following: Electrical Interference Interference form the transducer (search unit) Interference form the surface of the specimen Interference caused by mode conversion of the sound beam Interference caused by the shape of the specimen Interference caused by material structure Electrical interference can be caused by improper electrical connections of sound energy from the interface between the wedge and test specimen surface. In Immersion Testing, Air bubbles either on the transducer or specimen can cause reduced signal amplitude form the back surface and at times also from the front surface. Surface Interface A small amount of surface wave energy is usually transmitted in all directions around a transducer as shown below. If the transducer is near the edge of a plate, a signal may appear on the CRT.   When inspecting with shear waves, it is possible to detect a surface discontinuity with the small amount of su