Terms definition
I. Welding
II. Weld joint.
III. Weld Surface.
IV. Defects
a. Welding defects.
b. Weld defects.
V. Terms used to define defects or defect names.
Method Used to analyze the defects.
There are two methods for the analysis of defects caused during welding process or occurs after welding process.
A. Distructive testing.
B. Non distructive testing
As our subject is NDT methods So, described first on NDT (non distructive methods.)
Non-Distructive Testing Methods are as follows.
1. Liquid penetration testing (LPT)
2. Magnetic particle testing. ( MPT)
3. Radiography testing. (RT)
4. Ultrasonic testing. (UT)
Today Topics and study NDT method is LPT.
1. Liquid penetration testing (LPT):
this testing is to performed on weld to detects only the surface defects such as blow holes, surface porosity, cracks, cluster porosity, etc.
working principle : capillary action and bloating action.
procedure: Three Solutions are required for theting the weld for surface defects. they are
a. Cleaner (to clean the surface of weld before application )
b. Penetrant ( after cleaning surface apply penetrant
c. Developer
weld surface to perform LPT should be free from slag, spatter, dust by mannul cleaning (wire brush, chisels, cloth ) then take cleaner solution and spray on the surface of weld and clean by cotton cloth.
after cleaning apply penetrant solution on the surface and left for dwell time that is minimum 10 minutes. completing dwell time clean the surface by applying cleaner on cloth and clean in one direction periodically then apply developer some distance about 200 mm away from weld surface through out the test weld surface and after some time if any defects in the tested weld its will show visually on weld surface indicated by penetrant colour defects nature indication.
I. Welding
II. Weld joint.
III. Weld Surface.
IV. Defects
a. Welding defects.
b. Weld defects.
V. Terms used to define defects or defect names.
Method Used to analyze the defects.
There are two methods for the analysis of defects caused during welding process or occurs after welding process.
A. Distructive testing.
B. Non distructive testing
As our subject is NDT methods So, described first on NDT (non distructive methods.)
Non-Distructive Testing Methods are as follows.
1. Liquid penetration testing (LPT)
2. Magnetic particle testing. ( MPT)
3. Radiography testing. (RT)
4. Ultrasonic testing. (UT)
Today Topics and study NDT method is LPT.
1. Liquid penetration testing (LPT):
this testing is to performed on weld to detects only the surface defects such as blow holes, surface porosity, cracks, cluster porosity, etc.
working principle : capillary action and bloating action.
procedure: Three Solutions are required for theting the weld for surface defects. they are
a. Cleaner (to clean the surface of weld before application )
b. Penetrant ( after cleaning surface apply penetrant
c. Developer
weld surface to perform LPT should be free from slag, spatter, dust by mannul cleaning (wire brush, chisels, cloth ) then take cleaner solution and spray on the surface of weld and clean by cotton cloth.
after cleaning apply penetrant solution on the surface and left for dwell time that is minimum 10 minutes. completing dwell time clean the surface by applying cleaner on cloth and clean in one direction periodically then apply developer some distance about 200 mm away from weld surface through out the test weld surface and after some time if any defects in the tested weld its will show visually on weld surface indicated by penetrant colour defects nature indication.
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