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.
Hot gas plastic welding is sort of a dead ringer for gas welding, nevertheless it employs lower temperatures. A specific gun produces hot air by using a feed for plastic, which makes the parts to melt and join them together. Its important for the plastic welding materials to hold similar chemistry. The technique is normally utilized for the manufacture of plumbers fittings, big chemical tanks, as well as heat exchangers, etc.