ONE OF THE OLDEST METHODS OF NON DESTRUCTIVE TESTING

BASED ON OLD OIL & WHITING PROCESS WIDELY EMPLOYED IN RAILROAD INDUSTRIES

DEVELOPED IN 1941 BY C. SWITZER & JOSEPH SWITZER

CAN DETECT SURFACE DEFECTS OR SUBSURFACE DEFECTS WITH SURFACE OPENING

DYE PENETRANT TESTING

SURFACE CRACKS, POROSITY, LAMINATIONS, LACK OF BOND AT EXPOSED EDGES LEAK IN TUBING, TANKS, WELDS ETC

DYE PENETRANT TESTING DPT IS BEST ADOPTED TO INSPECTION OF

FERROUS METALS NON FERROUS METALS CERAMICS POWDERED METAL PRODUCTS GLASS PLASTICS & SYNTHETIC MATERIALSDYE PENETRANT TESTING DPT IS USED WITH EXCELLENT SUCCESS ON

CLEAN THE SURFACE TO BE INSPECTED

APPLY THE PENETRANT

CLEAN THE SURFACE WITH CLEANER AFTER 10 - 15 MINUTES

APPLY DEVELOPERDYE PENETRANT TESTINGBASIC PRINCIPLE

DYE PENETRANT TESTINGEXCESS PENETRANT REMOVEDDEVELOPER APPLIED

LIQUID PENETRANT TESTING

TYPES OF PENETRANTS

-BASED ON DYEDYE FLUORESCES UNDER BLACK LIGHT

HIGHLY CONTRASTING UNDER WHITE LIGHT

-MANNER IN WHICH THEYWATER WASHABLEARE REMOVEDSPECIAL SOLVENT

-POST EMULSIFICATIONNOT THEMSELVES WATERPENETRANTSWASHABLE , MADE BY APPLYING EMULSION

TYPES OF DEVELOPERDRY

WET

LIQUID PENETRANT TESTING

BASIC INSPECTION PRINCIPLE

1.PENETRANT MUST ENTER THE DEFECT IN ORDER TO FORM INDICATION

-SURFACE MUST BE CLEAN

-DEFECT MUST BE FREE FROM CONTAMINATING MATERIALS

-SUFFICIENT PENETRATION TIME TO FILL THE DEFECT

2.WASHING OF PENETRANT SHOULD BE DONE VERY CAREFULLY(VISIBLE DYE METHOD)

3.SMALLER THE DEFECT LONGER THE PENETRATING TIME

4.IF SURFACE DISCONTINUITY IS WIDER THAN IT IS DEEP, USE POST EMULSIFICATION METHOD

LIQUID PENETRANT TESTING

VISIBLE DYE - PENETRANT METHODS

TYPE OF DEFECT PENETRATION TIME (MIN.)

HEAT TREAT CRACKS 2 GRINDING CRACKS10FATIGUE CRACKSIN PLASTIC1 - 5IN CERAMICS1 - 5IN CUTTING TOOLS1 - 10IN FORGINGS20IN WELDS10 - 20COLD SHUTS IN DIE CASTING10 - 20POROSITY IN CERAMICS3 - 10 IN WELDS10 - 20 LAPS IN FORGING20SEAMS10 - 20

DYE PENETRANT TESTINGTHOROUGH CLEANING OF THE SURFACEPENETRANT SEAP INTO THE CRACK

DYE PENETRANT TESTINGCLEANER SPRAY REMOVES PENETRANT FROM SURFACEBUT NOT FROM THE CRACKDEVELOPER ACTS AS A BLOTTER TO DRAW PENETRANT FROM THE CRACK

BLACK LIGHT CAUSES FLUORESCENT PENETRANT TO GLOWDYE PENETRANT TESTING

DYE PENETRANT TESTING