ASME Boiler and Pressure Vessel Code (BPVC), Section IX contains qualification standard for the following; Welding, Brazing and Fusing procedures Welders and welding operators Brazers and brazing operators Plastic fusing operators Section IX is a reference document for the qualification of material joining (welding, brazing and plastic fusing) processes, used by various construction codes such as Section I, III, IV, VIII, XII, etc. NOTE: The different material joining processes covered….
Magnetic Particle Testing (MT) (also known as magnetic particle inspection – MPI) is a non destructive test (NDT) method, used to detect surface or subsurface (near to surface) discontinuities. This NDT method can be used on metals which can be easily magnetized (ferromagnetic). Metals can be classified as ferromagnetic, paramagnetic, or diamagnetic. Ferromagnetic metals: Ferromagnetic metals are those, which are strongly attracted to a magnet and can be easily magnetized…..
Oxy-fuel welding (OFW) is also known as Gas welding or Oxy-fuel gas welding. The term ‘Oxy-fuel’ is used to denote a combination of Oxygen and a Fuel gas, means it’s a process in which Oxygen and a fuel (combustible gas) both are required. Most commonly used fuel gas is Acetylene and thus the name Oxy-Acetylene welding (OAW) is also used for this process, when Acetylene is used as a fuel….
Thickness range for performance qualification (welder qualification test): ASME BPVC section IX has provided guidelines for the thickness range up to which a welder can weld. This can be found in Table – QW 452.1(b) of ASME BPVC Section IX (2017 edition). A simplified version of that table is given below; According to this table three important points can be drawn: The maximum thickness which a welder can weld is….
ASME Boiler and pressure vessel code (BPVC) has assigned certain numbers to base metals as well as to filler metals (electrodes). For base metals, ASME has assigned two number system, these are; P Numbers Group Numbers For filler metals, the number system which are assigned, are as follows; F Number A Number These numbers can be found in ASME BPVC Section IX (2017 edition), please see Table–1 for details; Table….
Heating the base metal to a specific desired temperature before welding is called as preheating. The temperature at which the base metal is heated is called as the preheat temperature. Preheat temperature can be determined by the applicable code. Please see table 1 to know how to find the preheat temperature in the respective code: In absence of code, the following factors shall be considered for determining the preheat temperature;….
Submerged Arc Welding (SAW) is an arc welding process in which arc is generated between a bare electrode and the workpiece. The arc and the molten weld pool are submerged in a blanket of granular fusible flux on the workpiece. Flux covers the arc and prevents fumes, sparks, spatter, and intense ultra violet radiation from escaping, which makes this process very different from other arc welding processes. Submerged arc welding….
Flux cored arc welding (FCAW) is a welding process that uses the heat produced by an arc generated between a continuous tubular filler metal (electrode) and the work piece. The filler metal is hollow with flux at the core. Flux present at the core of the filler metal shields the molten weld pool from atmospheric contamination. Flux Cored Arc Welding are mainly of two types: Self-Shielded (FCAW – S) Gas….
High frequency sound waves (frequency > 20000 HZ) also known as ultrasonic waves are introduced in a test object through a probe, these waves travel through the material on a predictable path. The waves are reflected at interfaces or other interruptions or discontinuity. The reflected waves are detected and then analysed for the possibility of any discontinuity in the test object. Sound beam is emitted through a probe. The probe….
SELECTION OF PROBE ANGLE: There are three methods for selecting a probe angle, these are: Based on groove angle: Probe Angle (Ø) = 90 – α/2 Where, α – Groove angle and Ø- Probe Angle As per AWS: 0 – 30 mm Thickness – 700 Probe 30 – 40 mm Thickness – 600 Probe > 40 mm Thickness – 450 Probe As per approved procedure:….
Visual examination of weld joint is an important activity, carried out to check the integrity and soundness of the weldment. It is an economical activity, as it doesn’t require any costly equipment. It must be carried out by a well experienced inspector. Main responsibilities of a welding inspector are: Code compliance Workmanship control Documentation Control The requirements of visual examination are: Illumination should be at least 350 Lux (minimum) but….
Gas Tungsten Arc Welding (GTAW) is also known as Tungsten Inert Gas Welding (TIG Welding). It is an arc welding process that uses a non-consumable electrode made up of Tungsten (or alloy of tungsten). Arc is generated between the tungsten electrode and work piece to establish the weld pool. Inert gas (Argon or Helium) is used to shield the molten weld pool during welding. Additional filler metal may be added….