REVEALING SURFACE CRACKS IN METALS
Liquid penetrant testing (PT) identifies finite surface defects that the human eye might miss. The term penetrant material includes all penetrants, solvents or cleaning agents used in this examination process.
The basic principle of liquid penetrant testing (PT) is capillary action, similar to blotting paper. Capillary action allows the penetrant to enter the opening of the defect, remain there when the liquid penetrant is removed from the material surface, and then re-emerge on the surface on the application of a developer. Through PT, surface-breaking on non-porous material, such as hairline cracks, surface porosity, leaks in new products, and fatigue cracks, can be detected. Whenever necessary, a more sensitive method shall be used – fluorescence PT.
Liquid dye penetrant testing is commonly used to inspect the surfaces of non-porous assets made out of ceramics, plastics, and metals, where inspectors will be looking at:
In these materials, inspectors will be using dye penetrants to look for defects like:
- Joint flaws
- Surface porosities
- Cracks (cracks from fatigue, hairline cracks, or grinding and quenching cracks)
- Incomplete fusion
Liquid penetrant testing (PT) identify surface defects so small they might be missed by the human eye.
By using liquid dye, it can detect surface-breaking on non- porous material such as hairline cracks, surface porosity, leaks in new products, and fatigue cracks.
Using capillary forces, low-tension liquid penetrant is applied into clean and dry surface-breaking defects to spread.
After appropriate time has gone, our testing team will remove excess penetrant and pull the dye penetrant out of the pores and cracks, creating indications which can then be evaluated.
Case Study :
Customers doing 3D printing and AM
Not knowing the acceptance criteria for the items to be tested is what the customers always have a complicated issue with the surveyors and their clients.
Surface preparation before an inspection / porous material
Most of the time, the acceptance criteria to be used are one of the problems. Be the bridge between the clients and their customers. We are finding common ground for our clients between the requirements specifications demanded by the industry against the application of the sample.
Some customers would not want their coatings removed because they’ve taken measures to protect the sample/equipment from rusting or corrosion. Clients would not see how porous material would affect the foundation of the liquid penetrant testing. Removing the coating is mandatory as it’ll adversely affect the inspection results. Showing the clients the inspection results due to the coating layer or porous material would convince them.
– Assist in understanding the different views from different parties, considering the situation and explaining it better to each party.
– The explanations given are comprehensive and straightforward.
APPLICATION OF LIQUID PENETRANT TESTING
Globally accepted non-destructive testing method
Easily determine surface cracks, pores, lack of fusion and inter-granular corrosion
Penetrant testing can be used on a wide range of materials (also non-ferrite and composite)
Fast and efficient testing method to cover large-area and surfaces
Easily determine surface cracks
Used on a wide range of materials
Fast testing method to cover large-area surfaces
Common Test Methods
ASME SEC V, Article 6 & 24
BS EN ISO 3452-1
Talk to us today
Our skilled and experienced team will detect acceptable defects and cracks in ferrous and non-ferrous materials in our state-of-the-art lab facility. Contact us today for more information about our liquid penetrant inspection services or to request a quote.