Pitting Procedure

Only available on StudyMode
  • Download(s) : 73
  • Published : December 15, 2012
Open Document
Text Preview
1.0 Scope

This procedure define some criteria for the surface finish for the hull structural steel & aluminium plates and wide flats and as well as treatment of imperfections and defects which may occasionally occur on the surfaces of these products.

2.0 Reference documents

1.IACS repair quality standard for existing ships
2.Grandweld QMS procedures
3.IACS guidelines for surface finish of hot rolled steel plates and wide flats

3.0 Definitions
Defects :
Cracks, shells, sand patches, pitting and sharp edged seams are always considered defects

4.0 Repair procedure
4.1 Grinding repair:

4.1.1 Grinding may be applied provided:

a.the nominal product thickness will not be reduced by not more than 3 mm of the original thickness.

b.Each single ground area does not exceed 0.25 m2 and

c.All ground areas do not exceed 2% of the total surface in question.

4.2 Welding repair:

4.2.1 Local defects which cannot be repaired by grinding as stated under 4.1 may be by chipping and /or grinding followed by welding subject to the following conditions:

4.2.2 Any single welded area shall not exceed 0.125 m2 and the sum of all areas shall not exceed 2% of the entire surface side.

4.2.3 The weld preparation must not reduce the thickness of the product below 70% of the nominal thickness.

4.2.4 The repair shall be carried out by the qualified welders using an approved welding procedure for the appropriate material grade.
tracking img