What is TIG Welding and its detail description ?

Significance of flow meter –

The pressure of the gas contained in cylinders is reduced by pressure-reducing valves (Manometers for indicating cylinder pressure).

The amount of gas flowing in l/min is controlled via a regulating valve and indicated by the flow meter. In order to prevent any errors, the pressure-reducing valves have a colour code corresponding to the gas type (black for inert gases).

The type of gas used is also indicated in the manometer.

Effect of Current and Inert Gas

Both direct and alternating currents are used for welding aluminium.

• The weld pool and the weld forms can be regulated by controlling the current type and the polarity.
• The heat developed is highest when helium is used.
• In direct-current, straight-polarity welding (electrode is negative with respect to aluminium), the heating of the electrode is kept to a minimum but the cleaning action on the weld pool is also minimum. Helium is used as the shielding inert gas.
• The breakdown of the oxide film is a result of the thermal stressing, i.e., melting occurs.
• Because of its high melting point (ca. 2050 °C), the oxide layer cannot be melted using argon as the shielding gas.