Glossary - E | BOC Industrial UK
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Glossary - E

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Electron Beam (EB) Welding

Welding process in which welds between metals are made using the heat from a concentrated beam of high velocity electrons. EB welding normally operates in a vacuum, but a variation of the process allows it to be carried out at atmospheric pressure.

Elongation

A term used in tensile testing as an indication of the ductility of the material under test. It is evaluated by comparing the distance between two marks ( the gauge length, l ) on a test specimen before testing begins, with the distance (L) between the same two marks after fracture of the specimen.
It is quoted as a percentage, and calculated from the equation:
Percentage Elongation = 100 x ( L - l ) / l , where l = original gauge length,
and L = length after fracture.

Equal Pressure Torch

A torch design in which the pressure of the oxygen and fuel gas are equal on the inlet side of the torch. This design is less suitable for equipment fitted with long hoses (greater than 50m) or if the fuel gas pressure is low.

Equilibrium

A state of balance. A condition in which opposing activities are balanced so that no overall change in state occurs.

Ethane

A fuel gas and a member of the paraffin family. A hydrocarbon molecule comprising two carbon atoms and six hydrogen atoms, C2H6.

Exothermic

See Exothermic Reaction

Exothermic Reaction

A chemical reaction in which energy is released as heat and light. The opposite of an endothermic reaction in which energy is absorbed.

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