liquid test

1. LIQUID PENETRATION TESTING
PRESENTED BY:-
DEPARTMENT: M.TECH- MECHANICAL ENGINEERING (DESIGN)
STUDENT ID-

2. NON DESTRUCTIVE TESTING
• Non-destructive tests (NDT) are methods that do not damage the parts being tested. NDT uses various
inspection techniques to assess individual or group components. By employing different principles from
physics, chemistry, and mathematics, NDT can test components without causing damage.
ADVANTAGES: 1). Tests are made directly on the object.
2). 100% testing of objects is possible.
3). Repeated checks over a period of time is possible.
LIMITATIONS: 1). Measurements are indirect and hence reliability is to be poor.
2). Skilled operator and judgement is required.

3. LIQUID PENETRANT TESTING
1). Penetrant inspection depends on the ability of liquid to wet the surface of a solid work or specimen and flow
over that surface to form a coating.
2). Due to surface tension and capillary action.
3). Visible light or ultraviolet light is required for the inspection.

4. PROCEDURE FOR LPT
• Cleaning.
• Penetrant Application.
• Removal of excess Penetrant.
• Application of developer.
• Inspection and Evaluation.

5. PROCEDURE FOR LPT: CLEANING
• Primary step.
• Scale, flakes, dirt, grease and other chemicals are removed.
• Solvents, brushes, rags are used to remove.

6. PROCEDURE FOR LPT: PENETRANT
APPLICATION.
• The penetrant fluid is spread freely and evenly over the surface and move into the crack.
• Dwell time is about 20-30 minutes the amount of time required for the penetrant to move into the
crack.
• Application of penetrant maybe achieved by dipping the component in a bath of penetrant/by
brushing/ by spraying.

7. PROCEDURE OF LPT: REMOVAL OF EXCESS
PENETRANT.
• The most important step.
• Surface is completely clear of penetrant.
• Crack/defect retains all the penetrant that entered into it.

8. PROCEDURE OF LPT: APPLICATION OF
DEVELOPER.
• After removing the excess penetrant from the surface of a specimen, a thin coating of developer is
applied over the surface.
• It absorbs the penetrant into the crack and increase visibility.
• Another important function of a developer is that it covers the surface with a colour that provides
good visual contact of penetrant.
• This increases the visibility of the crack.

9. PROCEDURE OF LPT: INSPECTION AND
EVALUATION.

10. RESULTS
• Scanning of surfaces for indication.
• The scanning maybe carried out under visible light conditions or with
ultraviolet light or LASER incident light.
• Defect recognition maybe made with human eye or automated optical
scanners.
• Each indications should be evaluated.