N
NACE National Association of Corrosion Engineers (USA) www.website
NACEMR National Association of Corrosion Engineers Material Requirements
NANU Notice Advisory to Navstar Users
NAPCA  National Association of Pipe Coating Applicators (USA) www.website
NAPIMS National Petroleum Investment Management Services www.webpage (division of NNPC)
NARUC National Association of Regulatory utility Commissioners (USA) www.website
NAS National Aerospace Standard (see the store of the Aerospace Induustries Association)
NATC Non-recallable Available Transfer Capability
NAUTICUS  DNV software for hull condition analysis
NAV IMO Sub-Committee on Safety of Navigation  
NB  Notified Body
  New Building (DNV) 
NBBPVI National Board of Boiler and Pressure Vessel Inspectors (USA) www.website 
NBS  National Building Specifications (UK) www.website
  National Bureau of Standards (USA)
NC  Normally Closed
  Non Conforming
NCD Non-Coincident Demand
NCP  National Contingency Plan
NCR  Non Conformance Report
NCS  Norwegian Continental Shelf 
ND Nominal Diameter
NDB Non Directional Beacon
  Navigational Data Base
NDBC National Data Buoy Center (US, division of the NOAA)
NDC  Netherlands Diving Centre 
NDE Non Destructive Examination
NDO  Neglect of Differential Overlap
NDT Non Destructive Testing (www.professional magazine online)
NEA National Energy Act (of 1978 / USA)
NEB National Energy Board (Canada)
NEBA Net Environmental Benefit Analysis
NEBOSH National Examination Board in Occupational Safety & Health (UK)
NEC National Electric Code (US) see NFPA
NELP  National Employment Law Project 
NEMA  National Electrical Manufacturers Association (USA) www.website
NEPA National Energy Policy Act (of 1992 / USA)
NERC National Environment Research Council (UK) www.website
  North American Electric Reliability Council
NETA  InterNational Electrical Testing Association (USA) www.website
NETCO  National Engineering and Technical Company Limited (a division of NNPC
NEXT  Near End CrossTalk
NF Norme Française (see AFNOR)
NFC National Fire Code
NFPA National Fire Protection Association (USA) www.website
NGA Natural Gas Act (of 1938 / USA)
NGC The Nigerian Gas Company www.webpage (division of NNPC)
NGDC National Geophysical Data Center  (USA) www.website
NGL  Natural Gas Liquid
NGNGV  Next Generation Natural Gas Vehicle (Program of the DOE)  
NGO  Non Governmental Organisation
NGPA Natural Gas Policy Act (of 1978 / USA)
NGSA Natural Gas Supply Association (USA)
NHC   Nordic Hydrographic Commission (IHO) www.webpage 
NI Nautical Institute
NID  Nominal Inside Diameter
NIOC  National Iranian Oil Company www.website
NIOHC  North Indian Ocean Hydrographic Commission (IHO) www.webpage
NISO  National Information Standards Organization (USA) www.website 
NIST  National Institute of Standards and Technology (USA) www.website 
NLL  Normal Liquid Level
NLNG  Nigerian LNG limited www.webpage (division of NNPC)
NMEA  National Marine Electronics Association (USA) www.website 
NMD  Nominal Model  
  Norwegian Maritime Directorate www.website
NMO  Normal Move Out 
NMVOC  Non Methane Volatile Organic Compound
NOAA National Oceanographic and Atmospheric Administration www.website
NODC National Oceanographic Data Center (USA) www.website
NNPC  Nigerian National Petroleum Company www.website
NNTU  Norwegian University of Sciences & Technology 
NNS  Northern North Sea. 
NO Normally Open
  Normal Output (fluorescent lighting)
  Not Open
NOAA National Oceanic and Atmospheric Administration (USA)
NOAEL No Observed Adverse Effect Level 
NOC  National Oil Company 
NOFO  Norwegian Clean Seas Association for Operation Companies
NOGEPA  The Netherlands Oil and Gas Exploration and Production Association www.website 
NOPR Notice Of Proposed Rule making
NOPSA  National Offshore Petroleum Safety Authority (Australia) 
NORAD Norwegian Agency for Development Co-operation
NORM Naturally Occurring Radioactive Material 
NORSOK Standards developed by the Norwegian Petroleum Industry
NOSAC  National Offshore Safety Advisory Committy (US) 
NOSCA Norwegian Oil Spill Control Association
NOSCP National Oil Spill Contingency Plan
NOSPC National Oil Spill Planning Committee
NOSRC National Oil Spill Response Centre
NOx Oxides of Nitrogen
NPCC Northeast Power Coordination Council (NERC Region, USA)
NPD  Norwegian Petroleum Directory www.website
NPDC Nigerian Petroleum Development Company (division of NNPC
NPS  Nominal Pipe Size
  National Petroleum Show (of Alberta, Canada)
NPSH Net Positive Suction Head
NPSHA Net Positive Suction Head Available 
NPSHR  Net Positive Suction Head Required 
NPT  Normal Pressure and Temperature
  National Pipe Taper (pipe thread specification)  
  Non-Productive Time  
  Non-Programmable Terminal 
  No-Path Trigger
  Normal Pipe Thread  
NPV  Net Present Value 
NR  Noise Rating (unit)
NRC National Response Corporation (USA)
NRCV  Non Return Circulation Valve
NRDA  Natural Resource Damage Assessment
NRI Net Revenue Interest
NRP  Number of Required Pump 
NRSC  National Remote Sensing Centre
NS  Nitrogen Supply 
NSB  Natural Sea Bed 
NSHC North Sea Hydrographic Commission (IHO) www.webpage 
NSOP Normal Service Operating Pressure
NSOT Normal Service Operating Temperature
NSO STRUDL ("as built"format)
NSRI  National Subsea Research Institute (Aberdeen University) 
NTU Nephelometric Turbidity Unit 
NUG Non Utility Generator
NUM Numeric
NUTEC  Norwegian Underwater Technology Center www.website
NVR  Non Volatil Residue 
NWS North West Shelf
NYSC  National Youth Service Corps (Nigeria) 
NZOI New Zealand Oceanographic Institute