DNV DNV-CP-0347 PDF

Scope and application

This programme is applicable for the approval of material manufacturers of:

— Steel hollow sections,

as referred in the Society's rules and standards, e.g. DNV-RU-SHIP Pt.2 Ch.2 Sec.2 [2]. For a description of general requirements, conditions and procedures related to the approval, please refer to DNV-CP-0346 which shall be applied in combination with this programme.

Note:

Manufacture of steel pipes used in the construction of piping for pressure, cargo, and process systems is not covered by this program, but shall follow the programme DNV-CP-0252

This CP does not cover any further assembly of hollow sections by welding, which requires additional approval according to DNV-CP-0352.

The product(s) used for approval testing (see Sec.3) will place limitations on the range of approval. The approval will be limited to the type of steel hollow section (i.e. circular/rectangular) and manufacturing method (welded/seamless) as indicated in App.A.

The applicable scope of approval depends on the dimensions presented and tested for the qualification tests. As a rule the dimensional limits in Table 1 apply. If deemed necessary by the Society, different dimensional limits may apply.

The wall thickness of the hollow section covered by the approval is related to the scope of testing and the actual wall thickness presented in the approval test. If deemed necessary by the Society, different limits on the wall thickness may apply.

Applicable approval for wall thickness for hollow sections without impact tests (< 6 mm) is limited to max. 6 mm.

Applicable approval for wall thickness for hollow sections with impact tests (≥ 6 mm) is limited to the maximum thickness of the tested product.

The designation ”steel type group” is applied for:

— carbon and carbon-manganese (C and C-Mn) steels

— the individual alloy steels

— the individual stainless steels.

For material grades and heat treatment/delivery condition, the same limitations as indicated in DNV-CP-0243 apply.

When steel hollow sections manufacturer operates their own steel making and/or rolling facilities to produce their own pre-material (plates/billets/ingots etc.), the manufacturer shall also use class programmes DNV-CP-0242 and DNV-CP-0243 to approve these facilities as appropriate.

When pre-materials/starting material are not produced at the steel hollow section manufacturer, these shall be procured from steelmaker/rolling mill approved by the Society for relevant steel grades.

Manufacturer’s own heat treatment facilities shall be evaluated and approved by the Society either under this approval programme, or as an approved "heat-treatment workshop" through the separate approval programme DNV-CP-0351.

If critical manufacturing steps are performed by a sub-supplier, the Society's manufacturer approval of the sub-supplier may be required accordingly.