dye penetrant inspection dp, liquid penetrate inspection lpi or penetrant testing pt to carbon steel welds. the penetrant ma

applied background carbon closeup color construction control destructive detection dye equipment examination factory ferrous horizontal image industrial industry inspection liquid lpi manual material materials metal method non nondestructive nonferrous pattern penetrant penetrate penetration photography photos process production quality rough rusty steel structures surface test testing texture tool welding welds white work workpiece workshop