Butane is an alkane with the formula C4H10. it is a gas at room temperature and atmospheric pressure, is a highly flammable, colorless, easily liquefied gas that quickly vaporizes at room temperature. Normal butane can be used for gasoline blending and as a fuel gas.

Butanol may be used as a fuel in an internal combustion engine.

A weld between the edges of two metal plates, which meet but do not overlap.

The end joint between two plates or other members which meet end to end. Typically a butt joint is used to describe the welded connection between two plates in the transverse direction.

A butterfly valve is a valve that isolates or regulates the flow of a fluid.

Lines obtained by cutting the hull surface with longitudinal planes parallel to the ship’s centre line.

A small single cell battery shaped as a squat cylinder resembling a button.

see International Convention for the Control and Management of Ship’s Ballast Water and Sediments (BWM Convention).

Any arrangement to control and turn away a fluid from its main flow path.