Liquid Penetration Testing (LPT) is a very common NDT technique used to identify surface defects of a material or an object.
This method is effective for detecting cracks, porosity, and other surface discontinuities.
Level-II Qualification is required to examine this.
Testing Process
- Step 1 - Clean the Test Piece (Inspecting Surface) with clean and dry lint-free cotton cloth.
- Step 2 - Clean the surface with Acetone/Cleaner using lint-free cotton.
- Step 3 - Let the surface dry, then apply Red Penetrant to the test surface.
- Step 4 - Wait for minimum 12–15 minutes, then clean the excess penetrant with dry cloth first.
- Step 5 - Clean excess penetrant with Acetone/Cleaner (with firm hand and in one direction only, do not rub).
- Step 6 - Wait for drying, then apply White Developer on the surface and wait for defects to develop.
- Step 7 - Examine the defects as per acceptance standards.