For those unfamiliar with welding or welding regulators, they look much like the gas regulator on the propane tank you have on your gas grill in the backyard. Regulators on a propane can are preset to deliver the right amount to your grill and burners. But when you’re welding the flow needs to be adjusted and there may be more than one welding regulator on a gas bottle used for welding.
A welding regulator is necessary to monitor the flow of shielding gas to the welding puddle. Gas must come out smoothly and controlled to the welding arc. If you were to skip the regulator and hook up a hose directly to a pressurized gas bottle, the gas could be released in its entirety in seconds. Likely it would blow out the arc in the process. The regulator does just what it sounds like, it regulates the gas flow. The pressure can then be set to a usable and less wasteful level.
The rate of flow can be adjusted by twisting a knob one way or the other to increase or decrease flow. Most MIG welding regulators will have two gauges; one to show the flow rate, the other to show the gas bottle pressures. The gas bottle pressure reading will let you know how much gas is left in the bottle. As the gas is used, the pressure will drop and the reading on the gauge will thus indicate.
Welding regulators often measure flow as either liters per minute or cubic feet per hour. Flow rates vary with each process. Wire thickness and welding amperage will impact the shielding gas flow rate required. The thicker the metal the more gas you’re likely to need. The material will impact the flow rate too. If you are welding steel or aluminum you’ll need different rates of flow. TIG welders sometimes opt for a more precise regulator. You can get one with a plastic ball that floats up and down in the gas flow inside the gauge. These are much more accurate than your basic welding gas regulator.