When it comes to quality of materials, the petrochemical industry can take no chances. A failure of pipelines or pipe fittings such as a flanges or couplings in service can be catastrophic and very costly in terms of damage and lost production.

It is therefore important that all materials are rigorously tested before they are dispatched, as small irregularities in the crystalline structure of the steel can cause fractures, which in turn cause the material to fail when subjected to high pressure and temperatures. It is important to detect these irregularities and specialist detection techniques have to be used.

One such technique is Magnetic Particle Inspection. At some time almost everyone will have carried out an experiment at school where a sheet of paper is laid over a magnet and then iron filings sprinkled over the paper. The iron filings will then align themselves to display the lines of the magnetic field.

Magnetic Particle Inspection is similar in principle, albeit more sophisticated. The part to be tested is subjected to an electromagnetic field to magnetise it. It is then coated with iron oxide either in powder form or in a liquid suspension. Any irregularities in the steel cause an irregularity in the magnetic field, which can be seen in the patterns in the iron oxide. These irregularities can indicate possible faults in the material which can then be investigated further.

At Chemipetro we supply quality materials such as pipe flanges, and we can carry out several specialist testing techniques on critical parts including Magnetic Particle Inspection to ensure the quality of our products.