Liquid non-destructive testing, which is another non-destructive testing method, is applied to the cracks on the surface of the materials. Penetrant liquid is applied to these cracks, which is then removed from the surface. Cracks are detected by removing the liquid remaining in the defective areas on the surface. Penetrant inspection method is used to detect leaks or cracks on the surfaces of the materials. This method is useful because it is both simple and inexpensive and can be applied to all kinds of materials.
In general, the color of the penetrant liquids is red. The feature of this liquid is that it can enter the cracks and voids found on the surface of the material. Some penetrant liquids are sensitive to ultraviolet rays. These are called fluorescent penetrant liquids.
If the surface of the part or material to be examined has a very porous structure, then applying liquid penetrant inspection does not give very healthy results. The steps followed during the inspection are generally as follows: pre-cleaning, application of liquid penetrant, waiting for penetration, intermediate cleaning, application of development fluid, examination, evaluation and preparation of the report.
Liquid penetrant inspection method is one of the oldest non-destructive testing methods. In the past, oil or diluted lime was poured into the cracks in the castings and welds which were not seen with the naked eye so that they were visible. Over time, a number of improvements were made and the method applied today was reached. This method is widely used in industry today. Today, the materials with cracks on the surface are immersed in a non-fluid liquid penetrant and expected to fill the cracks and voids on the surface. After the surface is dried, the cracks filled with liquid take the form of wet streaks. In this way, small cracks and gaps that cannot be easily noticed by the eye become visible.
Standards for Liquid Penetrant Inspection
The liquid penetrant inspection method, which is a practical and inexpensive non-destructive test method, is very sensitive to very small and adjacent cracks and voids. 4 can detect errors up to micron. It is also a simple method of implementation. It can be applied to almost any kind of materials. With these avatars, it is highly preferred in the industry.
Today, there are many test and inspection organizations that apply and evaluate the liquid penetrant inspection method. What is important is that these studies are carried out by mechanical engineers having PT23277 and PT1289 certificates in compliance with TS EN ISO 1 Non-destructive testing of welds - Penetrant testing of welds - Acceptance levels standard (previous TS EN 2 standard).
In order to ensure reliable and healthy results of liquid penetrant examinations, procedures must be performed in accordance with standards. The standards used in the implementation of this method are as follows:
- TS EN ISO 3452-1 Non-destructive testing - Penetrant inspection - Part 1: General requirements
- TS EN ISO 3452-2 Non-destructive testing - Penetrant inspection - Section 2: Test of penetrants
- TS EN ISO 3059 Non-destructive testing - Penetrant inspection and magnetic particle inspection - Inspection conditions
- TS EN 1371-1 Castings - Liquid penetrant inspection - Part 1: Sand, non-pressure and low pressure die castings
- TS EN 1371-2 Castings - Liquid penetrant inspection - Part 2: Precision castings
- TS EN 10228-2 Non-destructive testing of forged steels - Part 2: Penetrant inspection
our organization TÜRCERT Technical Control and Certification Inc.provides liquid penetrant inspection services within the scope of non-destructive testing services with a competent manager and employee staff and a strong infrastructure.