STAINLESS STEEL PIPEWORK

We are all concerned about the high losses of fishing vessels due to flooding.  The condition of seawater pipework is a very important factor in helping to prevent such losses.

To their credit, some owners are choosing to fit stainless steel seawater pipework to reduce pipework corrosion.  However, MCA would like to make the industry aware that some grades of stainless steel are not entirely suitable for marine use. So heres the technical jargon!

When used with seawater, austenitic stainless steels may be susceptible to chloride stress corrosion cracking, possibly leading to fracture.  This is exaggerated in polluted water. Examples of austenitic stainless steels are 304/304L and 316/316L.

Increasing the nickel content is one solution (e.g. Alloy 330, 904L).  Alternatively, duplex or ferritic stainless steels should be used (e.g. 329, 2205, 439, 26Cr 1 Mo).

So by all means fit stainless steel pipework, but choose the suitable grade.