Manufacturing companies commonly use pressure vessels for different reasons. They are common when it comes to different types of liquid storage. However, ensuring their durability can be tough, and companies require regular inspection to ensure optimal performance for their vessels.
1. Visual Evaluation (VT)
Visual inspection is a type of testing that gives an overview of a pressure vessel condition. Pressure vessel inspectors observe different parts of the vessel, including inner surface and exterior. However, you should clean and well-lit the vessel before an inspection so it can be analyzing from every area.
They may give a final report about its appearance and working condition, which might even include problems such as corrosion, cracks, hydrogen blistering, or erosion. While a visual inspection can show some issues, it only provides you a direction about vessel repair and maintenance. Additionally, it would help if you used some other non-destructive testing approaches that may further reveal whether a pressure vessel’s structure and function are at an optimum level.
2. Liquid Penetrant Test (PT)
A liquid penetrant evaluation is a means of checking for defects on a pressure vessel on its surface. To begin with, an inspector flows an extremely thin liquid, called a penetrant, into the potential flaw. Typically, the penetrant is sprayed and let time to soak in. A tester may add a fluorescent chemical to the penetrant so that it will get more visible under ultraviolet lighting.
Once the penetrant dries, the inspector wipes it off and uses a developer to draw out any penetrant that has seeped through cracks. As the penetrant comes to the surface, it reveals if a seeping problem exists in a vessel. This testing process is frequently used on welded seams, but it may also be used on plates, bars, pipes, and more.
3. Magnetic Particle Test (MT)
In this test, the inspector runs a magnetic current using the prod method through the pressure vessel. If there exist any defects in the shell’s substance, a “flux leakage field” will appear. To put it differently, these flaws will interrupt the circulation of the magnetic current, causing magnetism to spread out.
The flux leakage field becomes more visible when the inspector spreads ferromagnetic particles on the vessel’s surface. Much like the liquid penetrant test, the inspector uses fluoresce under black light for a more precise estimate of the damage. As the metal particles are drawn to the magnetic current, they show the approximate measurements of any defects that have created flux leakage fields.