Any welding professional knows that more gas than is strictly necessary is normally used, but he knows he can not lower it because there are a number of uncontrolled parameters in the installation that can, and in fact to do, cause the flow to drops unexpectedly, for example ;
– Instantaneous drop of the line pressure by simultaneous entry of equipment. -down in the pressure of the bottle or the installation when there is lower gas.
-Increase resistance to the gas passage in the power cable and the torch cables by deformations or dirt.
– uncontrolled loses of the torch in some concrete position, etc…
Several coincidences of of these events at the same time can have fatal consequences ….
For all this, it can happen that being everything normal , apparently, we get a seam with symptom of lack of gas, solution? … we heal in health and adjust the flow for excess, .. just in case ….
But this is not here, there is more …
If we need more gas by necessity in a complicated seam, unfortunately we have it in all the work since we can not vary the gas seam to seam as it would be desirable.
IN OTHER WORDS.., THAT WE ADD TO THE UNCERTAINTIES OF THE INSTALLATION THE LACK OF GAS FLEXIBLE CONTROL
The welders also knows that not all cords need the same gas , even though they have the same current, position,
Material, dirt, geometry and position of the area to be welded is very important.
That is why reducing the gas flow required only as a function of current, as other equipment does, is too simplistic.