Liquid Penetrant Testing Level 2 (PT-2) Practice Exam

Which type of penetrant method requires additional steps for emulsifier application?

1. Water washable

2. Solvent removable

3. Post emulsifiable

4. Self emulsifying

The correct answer is: Post emulsifiable

The post-emulsifiable penetrant method requires additional steps for emulsifier application because it involves a multi-step process to develop the indications effectively. In this method, after applying the penetrant and allowing it to dwell on the surface of the test object, an emulsifying agent is then applied to the penetrant. This step is critical as it allows the penetrant to mix with the emulsifier, which, in turn, helps wash away excess penetrant while retaining the penetrant that is trapped in any surface flaws. This technique is particularly useful in situations where the penetrant needs to be more effectively controlled, allowing for precise indication development. As a consequence, this method is more complex than others such as water washable or solvent removable methods, which have less stringent requirements for emulsification. In contrast, water washable, solvent removable, and self-emulsifying methods either use water or solvent to remove the penetrant without the need for an additional emulsification step or rely on a built-in capability to emulsify, making them simpler than the post-emulsifiable method. Therefore, the requirement for extra applications of emulsifier in post-emulsifiable techniques is what distinctly characterizes this method.