This was found on flange through Liquid penetrant testing
What it is.
Liquid Penetrant Testing (PT) is another way of finding imperfections such as cracks in the test piece. It differs from MT in that it does not need a magnetic field to expose any discontinuities, and can be used to inspect ferromagnetic and non-ferromagnetic materials. PT is a 6 step process starting with the initial cleaning and ending with the final cleaning. PT uses a dye (usually red) that is applied to the test surface and allowed to sit for an amount of time that is specified in the specification usually 10 to 15 minutes, this is known as the dwell time. After the elapsed dwell time, the test piece is cleaned off again and a developer is added, this will expose any imperfections to the inspector.
What do we do.
B-TEC’s PT level II technicians will come to your site with all the proper cleaning agents, dye penetrant and developers we can inspect almost every type of material.