TOOLS / WELDING

Shielding gas flow and cylinder duration calculator

Work out how long one shielding-gas cylinder lasts at your flow rate, and how many cylinders a job needs, so gas does not run out mid-shift.

One cylinder lasts6.67 hours

Cylinders for a 30-hour job: 5 (rounded up — keep a spare for changeover and flow checks).

Enter the contents printed on your cylinder and the flow you actually set. Typical starting flows are about 12–20 L/min for MIG and 8–15 L/min for TIG (filler/gas-maker tables); wind, nozzle size and joint type change the flow you need. Flow while welding, not at rest, is what empties the cylinder.

Formula

Duration (hours) = cylinder contents (litres) ÷ flow (L/min) ÷ 60. Cylinders for a job = job hours ÷ duration, rounded up.

Standard / source

Filler and gas-maker flow tables. Typical starting flows are about 12–20 L/min for MIG and 8–15 L/min for TIG; the right flow depends on nozzle size, joint, material and wind, so enter the flow you actually set rather than trusting a generic rate.

Worked example

Cylinder contents 6,000 litres, flow 15 L/min: duration = 6,000 ÷ 15 ÷ 60 = 6.67 hours. For a 30-hour job: 30 ÷ 6.67 = 4.5, rounded up to 5 cylinders. These are the calculator's default inputs, so it shows 6.67 hours and 5 cylinders on load.

Safety note

Planning and costing estimate only. Follow your gas supplier's cylinder handling, storage and regulator guidance, and never use a damaged cylinder or regulator.