Offshore Service – Magnetic Particle Inspection

20 Apr

Offshore Service – Magnetic Particle Inspection

What is Magnetic Particle Inspection?

It is a non-destructive testing (NDT) process to detect surface crack line in ferromagnetic materials.

Ferromagnetic materials such as iron can be found on the pipeline system in vessels. The pipeline system help to supply and distribute liquids and gases to different parts of a vessel.

One of the main advantages of magnetic particle inspection is that it can give an immediate indication of defects and discontinuities.

What caused pipes to crack?

Pipe age and material:

The older the pipe is, the higher the risk of cracks will be. For instance, water lines that are installed before 1980 tend to be made from cast iron. Although durable, cast iron can become brittle and crack due to constant expansion and contraction. New water pipes tend to be made of more resistant materials, such as plastic or ductile iron.

Pressure changes:

The pressure levels inside a water pipe can change due to several reasons. Temperature changes, or thermal expansion, are one of the most common causes. As the ground surrounding the pipe freezes and thaws, the pipes contract and expand, often resulting in cracks.

Corrosive soils:

Pipes made from iron and other metals can break over time if installed in acidic and corrosive environments. This happens most often in pipes that don’t have appropriate corrosion protection, such as polyethylene encasement for ductile iron pipes.

How Magnetic Particle Inspection Is Important To Offshore Maintenance?

Any crack in the water tank can also lead to engine room flooding.

The leak can also take place from any of the fresh or seawater pipelines due to which a lot of water can enter the engine room space, which will be a disastrous event.

How To Conduct Magnetic Particle Inspection In Four Steps?

  • 1) Induce a magnetic field in the specimen
  • 2) Apply magnetic particles to the specimen’s surface
  • 3) View the surface, looking for particle groupings that are caused by defects
  • 4) Demagnetize and clean the specimen