DNV -OS-C401 offshore construction standards contain technical requirements, principles and acceptance criteria related
to classification of offshore units as it pertains to DNV/GL classification society. Order your copy here:
This standard will:
— Provide an internationally acceptable standard giving the minimum requirements for fabrication of
offshore structures, installations and equipment by welding, including requirements for mechanical fastening,
testing and corrosion protection systems.
— Provide guidelines for designers, fabricators, manufacturers, suppliers, purchasers and regulators.
This DNV standard is written for world-wide application. Note: Country and local government jurisdiction regulations may
include requirements in excess of the provisions by this standard depending on the size, type, location and
intended service of an offshore unit.
The standard provides requirements for fabrication and testing of offshore units.
The standard gives requirements for the following:
— Contractors: Chapter Two – Section Two
— Welder qualifications: Chapter Two – Section Three
— Welding consumables: Chapter Two – Section Four.
— Qualifying weld procedures: Chapter Two – Section Five
— Tolerances: Chapter Two – Section Six
— ND testing: Chapter Two – Section Seven
— Coating and Corrosion Protection systems: Chapter Two – Section Nine
— Mechanical fastening: Chapter Two – Section Ten
Also included are the DNV’s recommendations on safe engineering practices for general use by the
The requirements in this standard apply to offshore units, installations and equipment fabricated by