39 Results
  • Nitrogen oxides (NOx)

    Nitric oxide (NO) and Nitrogen dioxide (NO2) are usually grouped together as NOx emissions.

  • Nitrous oxide

    Not to be confused with nitric oxide (NO) or nitrogen dioxide (NO2), nitrous oxide (N2O) a potent greenhouse gas...

  • Node

    A point that is at rest in a vibrating body.

  • Noise Code

    A new mandatory code for the protection of seafarers against noise on board.

  • Non-combustible material

    A material which neither burns nor gives off flammable vapours in sufficient quantity for self-ignition when heated...

  • Nondestructive test (NDT)

    Any test that does not damage the material under test and can, therefore, be used on the finished items.

  • Nondestructive testing methods of hull welds

    Inspection of welded joints is carried out by non-destructive methods, such as radiography, ultrasonic, magnetic...

  • Non-organic grease

    A type of grease which does not attack the seal.

  • Non-return valve

    A valve that is designed to prevent a reverse flow. If the valve disc is not attached to the spindle, it is called...

  • Non-volatile petroleum

    Petroleum having a flash point of 60°C or above, as determined by the closed cup method of test.

  • Normal conditions (on the bridge), normal sailing conditions

    Normal conditions exist when trouble-free operation of the equipment required for thebridge operation is given...

  • Normal operational and habitable condition

    A condition under which the ship as a whole, the machinery, service, means and aids ensuring propulsion, ability...

  • Normalising

    The type of steel heat treatment. The steel is heated to 850-950°C depending upon its carbon contents and then...

  • Not under command (NUC)

    A vessel which through exceptional circumstances is unable to manoeuvre as, required by the COLREGs.

  • Notch ductility

    The property of a material whereby it will withstand stress due to a notch or area of stress concentration without...

  • NOx emissions



    The Wärtsilä NOx Reducer System is based on the Selective Catalytic Reduction technique for Nitrogen Oxide (NOx...

  • NOx Technical Code

    The Technical Code on Control of Emission of Nitrogen Oxides from Marine Diesel Engines adopted by IMO.

  • Nylon

    A synthetic polymer which is chemically inert and resistant to erosion and impingement attack. It is used for orifice...

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