Magnetic Particle Testing

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 …

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(OFW) Oxy-Fuel Welding (Gas Welding/Oxy-Acetylene Welding)

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 …

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Thickness range for welder qualification and procedure qualification (ASME Section IX)

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 …

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P Number, F Number and A Number in welding (ASME Section IX)

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 …

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Preheating – How, When and Why

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: …

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(SAW) Submerged Arc Welding

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 …

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(FCAW) Flux Cored 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 …

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(UT) Ultrasonic Test Basics

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 …

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Visual Inspection of Weld Joints

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 …

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