Lisbon's Vasco da Gama Bridge is the longest in Europe, spanning a total distance of 10.7 miles. Taking three years to complete, the bridge opened for traffic in 1998 to celebrate the 500th anniversary of Vasco da Dama's discovery of the maritime route from Europe to India.
The arc temperature may be upto 20,000 K. Although TIG welding produces the highest quality welds, it is a slow and expensive process. Metal inert gas welding process (MIG) is economical with consumable electrode fed at a predetermined rate. Plasma arc welding (PAW) has made substantial progress in utilising the high heat energy of an ionised gas stream.
Overview: Oxy Fuel welding (OFW) is a group of welding processes which join metals by heating them with a fuel gas flame or flares with or without the application of pressure and with or without the use of filler metal.here is one process of minor OFW, Oxy Fuel welding industrial significance, known as air acetylene welding, in which heat is obtained from the combustion of acetylene with air. Welding with methylacetone-propadiene gas (MAPP gas) is also an oxyfuel procedure.