Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that uses a non-consumable tungsten electrode to produce the weld. The weld area and electrode are protected from oxidation or other atmospheric contamination by an inert shielding gas (argon or helium). A filler metal is normally used, though some welds, known as autogenous welds, or fusion welds do not require it. When helium is used, this is known as heliarc welding. A constant-current welding power supply produces electrical energy, which is conducted across the arc through a column of highly ionized gas and metal vapors known as a plasma. GTAW is most commonly used to weld thin sections of stainless steel and non-ferrous metals such as aluminum, magnesium, and copper alloys. The process grants the operator greater control over the weld than competing processes such as shielded metal arc welding and gas metal arc welding, allowing for stronger, higher quality welds. However, GTAW is comparatively more complex and difficult to master, and furthermore, it is significantly slower than most other welding techniques. A related process, plasma arc welding, uses a slightly different welding torch to create a more focused welding arc and as a result is often automated.
Royal Leamington Spa, commonly known as Leamington Spa or simply Leamington /ˈlɛmɪŋtən/ (About this soundlisten), is a spa town and civil parish in Warwickshire, England. Originally a small village called Leamington Priors, it grew into a spa town in the 18th century following the popularisation of its water which was reputed to have medicinal qualities. In the 19th century, the town experienced one of the most rapid expansions in England. It is named after the River Leam, which flows through the town.
The town contains especially fine ensembles of Regency architecture, particularly in parts of the Parade, Clarendon Square and Lansdowne Circus.
In the 2011 census Leamington had a population of 49,662. Leamington is contiguous with the neighbouring towns of Warwick and Whitnash; these form a combined urban area which in 2011 had a population of 95,172.