Shielding gas protects the molten weld pool from the air. Too little gas causes porosity; too much wastes gas and can pull air into the arc. Here is how to choose and set up the right regulator.
Argon regulator vs argon flow meter
An argon regulator uses two gauges: one shows cylinder pressure and the other shows flow. An argon flow meter shows the flow on a clear tube with a floating ball, which many TIG welders find easier to read. Both reduce high cylinder pressure to a steady, low working flow.
Why CO2 needs a heater regulator
When CO2 expands from the cylinder it gets very cold, and the regulator can freeze up during long MIG runs. A CO2 heater regulator has a built-in electric heater that stops freezing and keeps the flow steady.
Typical flow rates
- TIG welding with argon: about 8 to 15 litres per minute for most work.
- MIG welding with CO2 or mixed gas: about 12 to 20 litres per minute, higher outdoors or with bigger nozzles.
These are starting points. Always follow the welding procedure and the equipment maker’s advice.
Check the flow at the torch
A leaking hose or connection means the gauge can show the right flow while less gas reaches the arc. A gas flow tester placed over the torch nozzle shows the real flow at the point of welding.
Common problems
- Porosity (holes in the weld): check for draughts, leaks, a blocked nozzle or a flow set too low.
- Frozen CO2 regulator: use a heater regulator.
- One cylinder, two machines: fit a Y valve to split the gas line.
- Safety: fit a reverse flow check valve to stop gas flowing back into the line.
Gas equipment in Singapore
Fong Yung Industries LLP supplies argon regulators, flow meters, CO2 heater regulators and gas fittings in the EVO-Gas range. Browse the range or request a quote.