Elements of Welding Symbols:
The first concepts the Welding Inspector must understand very well, are the welding symbols and how to interpret them on drawings. The reference line of the welding symbol, as shown below, is used to designate the type of weld to be…
Hardness Testing:
Hardness is the resistance of a material to localized deformation. The term can apply to deformation from indentation, scratching, cutting or bending. In metals, ceramics and most polymers, the deformation considered is plastic deformation of the surface.
For elastomers and some polymers, hardness is…
Here are some rarely used NDT – Few Other Methods
1. Eddy Current Testing – ET:
Eddy-current inspection uses electromagnetic induction to detect flaws in conductive materials. A circular coil carrying current is placed in proximity to the test specimen (electrically conductive). The alternating current in…
Positions for Welding Pipe
For welding pipe in shops, power plants, oil refineries, and chemical plants for crude oil, gasoline, and natural gas, the same basic welding positions described previously are used.
Flat Butt Weld Pipe Position…
The NDT (nondestructive testing) methods are:
Visual Inspection – VT
Liquid Penetrant Testing – LT
Magnetic Particle Testing – MT
Radiographic Testing – RT
Ultrasonic Testing – UT
Eddy Current Testing – ET (not used in field inspection)
Acoustic Emission Testing – AET (not…
Equipments and materials for NDT lab set up
Radiography Testing:
1) X-Ray tube head -450 kV capacity ( only if construction of a exposure room with approval from government is possible)
2) RT Films (D4 )
3) lead screen 0.125mm, 0.25 mm
4) Film casettes
5) set of IQI -wire…
Acceptance Criteria for Liquid Penetrant Testing -LPT as per ASME , AWS and API standards
Liquid penetrant testing simply called as PT. Sometimes Dye Penetrant Testing is a surface defect detection NDT method and is more sensitive to all kind of surface defects, such as…
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…
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…