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C: Informative References [Table of Contents] Ch.2: Technical Provisions

DNV-OS-C401 Fabrication and Testing of Offshore Structures

[-] Ch.1: Introduction
[-] Sec.1: Introduction
[-] D: Definitions

Ch.1 Sec.1
D. Definitions

Ch.1 Sec.1
D 100   Verbal forms

Ch.1 Sec.1 D
101   Shall: Indicates a mandatory requirement to be followed for fulfilment or compliance with the present standard. Deviations are not permitted unless formally and rigorously justified, and accepted by all relevant contracting parties.

Ch.1 Sec.1 D
102   Should: Indicates a recommendation that a certain course of action is preferred or particularly suitable. Alternative courses of action are allowable under the standard where agreed between contracting parties but shall be justified and documented.

Ch.1 Sec.1 D
103   May: Indicates a permission, or an option, which is permitted as part of conformance with the standard.

Ch.1 Sec.1 D
104   Can: Can-requirements are conditional and indicate a possibility to the user of the standard.

Ch.1 Sec.1 D
105   Agreement, or by agreement: Unless otherwise indicated, agreed in writing between contractor and purchaser.

Ch.1 Sec.1
D 200   Terms

Ch.1 Sec.1 D
201   Purchaser: The owner or another party acting on his behalf, who is responsible for procuring materials, components or services intended for the design, construction or modification of a structure.

Ch.1 Sec.1 D
202   Contractor: A party contractually appointed by the purchaser to fulfil all, or any of, the activities associated with fabrication and testing.

Ch.1 Sec.1 D
203   Unit: A general term for an offshore installation such as ship shaped, column stabilised, self-elevating, tension leg or deep draught floater.

Ch.1 Sec.1 D
204   Installation: A collective term to cover any construction, buoyant or non-buoyant, designed and built for installation at a particular offshore location.

Ch.1 Sec.1 D
205   Welding procedure: A specified course of action to be followed in making a weld, including reference to materials, welding consumables, preparation, preheating (if necessary), method and control of welding and post-weld heat treatment (if relevant), and necessary equipment to be used.

Ch.1 Sec.1 D
206   Preliminary welding procedure specification (pWPS): A tentative welding procedure specification providing required welding variables, which is assumed to be adequate by the contractor, but which has not been qualified by the purchaser.

Ch.1 Sec.1 D
207   Welding procedure specification (WPS): A welding procedure specification, which has been qualified by the purchaser to conform with an agreed qualification scheme.

Ch.1 Sec.1 D
208   Welding procedure qualification test (WPQT): The process of accomplishing welding and testing of a standardised test piece, as indicated in the WPS.

Ch.1 Sec.1 D
209   Welding procedure qualification record (WPQR): A record comprising a summary of necessary data needed for the issue of a WPS.

Ch.1 Sec.1 D
210   Welding production test (WPT):A test carried out to demonstrate that actual production welding meets the specified requirements

Ch.1 Sec.1 D
211   Non-destructive testing (NDT): Visual inspection, radiographic testing, ultrasonic testing, magnetic particle testing, penetrant testing and other non-destructive methods for revealing defects and irregularities.

Ch.1 Sec.1 D
212   Structural testing is a hydrostatic test, carried out in order to demonstrate the tightness of the tanks and the structural adequacy of the design. Where hydrostatic testing is not practically feasible, hydropneumatic testing may be carried out instead under provision that the test is simulating, as far as practicable, the actual loading of the tank.

Ch.1 Sec.1 D
213   Leak testing is an air or other medium test, carried out in order to demonstrate the tightness of the structure.

Ch.1 Sec.1 D
214   Hydropneumatic testing is a combination of hydrostatic and air testing, carried out in order to demonstrate the tightness of the tanks and the structural adequacy of the design.

Ch.1 Sec.1 D
215   Hose testing is a water test carried out to demonstrate tightness of structural items.

Ch.1 Sec.1 D
216   Shop primer is a thin coating applied after surface preparation and prior to fabrication as a protection against corrosion during fabrication.

Ch.1 Sec.1 D
217   Protective coating is a final coating protecting the structure from corrosion

Ch.1 Sec.1 D
218   Watertight means capable of preventing the passage of water through the structure under a head of water for which the surrounding structure is designed.

Ch.1 Sec.1 D
219   Weathertight means that in any sea conditions water will not penetrate into the ship.

Ch.1 Sec.1
D 300   Abbreviations

Ch.1 Sec.1 D
301   The abbreviations given in Table D1 are used in this standard.

Ch.1 Sec.1 D
Table D1 Abbreviations 
Abbreviation In full 
AC Alternating current 
ANSI American National Standards Institute 
ASME American Society of Mechanical Engineers 
ASTM American Society for Testing of Materials 
AWS American Welding Society 
BM Base material 
BS British Standard (issued by British Standard Institution) 
CE Carbon equivalent 
C-Mn Carbon manganese 
CTOD Crack tip opening displacement 
DAC Distance amplitude curve 
DC Direct current 
DNV Det Norske Veritas 
ECA Engineering critical assessment 
EN European de Normalisation 
FM Fracture mechanics  
HAZ Heat affected zone 
IACS International Association of Classification Societies 
ISO International Organisation for Standardisation 
MAG Metal active gas (welding) 
MIG Metal inert gas (welding) 
NACE National Association of Corrosion Engineers 
NDT Non-destructive testing 
PWHT Post weld heat treatment 
RP Recommended practice 
SMAW Shielded metal arc welding 
SMYS Specified minimum yield stress 
TIG Tungsten inert gas (welding) 
WM Weld metal or Deposit 

Ch.1 Sec.1
D 400   Latin symbols

Ch.1 Sec.1 D
401   The following Latin symbols are used:
a = size of test specimen 
b = size of test specimen  
d = diameter of round tensile test specimen 
df = distance from the plane of the fatigue pre-crack to the fusion line 
e = plastic deformation 
hT = test pressure height 
hop1 = vertical distance from the load point to the position of maximum filling height  
hs3 = vertical distance from the load point to the top of the tank 
hp0 = height corresponding to valve opening pressure when exceeding the general value 
hop2 = vertical distance from the load point to the position of maximum filling height. For tanks adjacent to the sea that are situated below the extreme operational draught (TE), hop2 is not normally to be taken as being less than TE 
hD2 = pressure head due to flow through pipes 
le = equivalent parameter for conical shells 
lmin = breadth of test assembly plates 
lr = length of template or rod 
r = nominal radius of the shell 
ra = actual distance from the centre of the sphere to the shell wall 
re = equivalent parameter for conical shells 
ra = actual distance from the cylinder axis to the shell wall 
s = distance between stiffeners or girders 
t = thickness 
t1 = wall thickness of the greater tube (can) 
t2 = wall thickness of the smaller tube (brace) 
A = diameter used in wrap around bending test 
C = diameter of roller in bend test 
D = outside diameter 
D1 = outside diameter of the greater tube (can) 
D2 =  outside diameter of the smaller tube (brace) 
KV = impact energy requirement 
Lo = length of test area in test specimens 
Lmin = length of test assembly plates 
N = number of 
R = radius 
Rc = forming radius 
T = thickness of plate in bend test 
W = width of weld 

Ch.1 Sec.1
D 500   Greek symbols

Ch.1 Sec.1 D
501   The following Greek symbols are used:
a = tubular joint angle 
d = measure of deformation compared to theoretical geometry 
li = length of area with acceptable location of the fatigue pre-crack 
n = Poisson's ratio 
s1 = largest compressive principal membrane stress 
s2 = principal membrane stress normal to s1 
y = ratio between principal stresses. 

C: Informative References [Table of Contents] Ch.2: Technical Provisions