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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 we...

  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...

  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, ...

 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 amo...

 The following should be considered when selecting equipment for magnetic particle testing. Is equipment for wet or dry method? Magnetization requirements (AC or DC) Demagnetization- incorporated or separate unit? Ampere required. Line voltage requirements. Accessories needed or required. WET HORIZONTAL EQUIPMENT To obtain circular magnetization , the specimen is clamped between the head and tail stocks . For longitudinal magnetization the coil is moved so that the area to be tested is encircled by the coil . A typical wet horizontal unit usually accommodates both AC sand HWDC magnetization . The wet continuous-field method has three basic steps: Flow bath through nozzle and over entire surface of part. Stop bath flow. Apply current at the instant bath flow is stopped. Dry continuous-field method With this method the powder is usually applied from a shaker, bulb, or Blower and follows these steps: Apply magnetizing current. Blow powder parti...

  Standards for Piping Design and Inspection: The original ASME B31 Code for Pressure Piping was first introduced in 1935 as the single document for piping design. In 1955, ASME began to separate the code into sections to address requirements of specific piping systems, as follows. B31.1: Power Piping is for piping associated with power plants and district heating systems as well as geothermal heating systems. Its main concern is the steam-water loop in conventionally powered plants. More recently, it has added a chapter to require maintenance plans for the plants that produce the power. B31.2: Fuel Gas Piping Code was withdrawn in 1988, and responsibility for that piping was assumed by ANSI Z223.1. It was a good design document, and although it has been withdrawn, ASME makes it available as a reference. B31.3: Process Piping (previously called the Chemical Plant and Petroleum Refinery Piping Code) is the code that covers more varieties of pipin...

  Ultrasonic Testing In Ultrasonic Testing we use something called “Ultrasonic Vibrations” we must know two facts about a vibration: A vibration is a back and forth movement. A vibration is energy in motion A depression of a surface from its normal position is called a displacement. Vibrations pass through a solid material as a succession of particle displacements; this can be visualized as shown below: The structure of a material is actually many small particles or groups of atoms. These particles have normal or rest positions and can be displaced from these positions by some force, when the force is removed, the particles will tend to return to their original positions. Energy is transmitted through a solid material by a serious of small material displacements within the material. The transmission of Ultrasonic vibrations through a material is related to the elastic properties of the material. In Ultrasonic Testing a transducer made of Piezo-electric crystals is ...