Shielding Gas Consumption

Estimating shielding gas

Multiply the flow rate by the total time gas is flowing. Add preflow and postflow for every start to the arc time. At 12 L/min, ten minutes of arc time plus sixty seconds of extra flow use 132 litres.

Scope

Flow and volume must use the same reference pressure and temperature. The allowance increases the calculated consumption. Obtain usable cylinder gas volume from its supplier. This tool does not infer cylinder contents from pressure or assess storage safety and ventilation requirements.

See the effect of short welds

Use flow 8 L/min, arc time 6 minutes and 12 starts. Choose 2 seconds of preflow and 3 seconds of postflow per start. Extra flow time is 12 × (2 + 3) = 60 seconds, or 1 minute. Total flow time is 7 minutes and net consumption is 8 × 7 = 56 L. Adding an example allowance of 25 percent gives 56 × 1.25 = 70 L. This allowance is not a process recommendation.

Dividing the same arc time into more starts increases preflow and postflow consumption. Weld length alone therefore cannot determine consumption. Do not automatically equate starts with part count, since one part may contain several weld starts. Also check which time fields use minutes and which use seconds.

The net value follows the measured flow and times, while the allowance value is a planning estimate. Entering an allowance does not remedy a gas leak. If stages use different flow rates, calculate each stage separately and add volumes at the same reference conditions. For comparison with cylinder capacity, use the available quantity of free gas.

Frequently asked questions

How much shielding gas is consumed per day?

For an example day with 120 arc minutes, 30 starts, flow 15 L/min, 1 second preflow and 3 second postflow, consumption including 10 percent allowance is 2013 L. Multiply flow by total gas time at matching reference conditions, noting that this calculation does not determine cylinder contents or ventilation safety.

Calculate with these values