Welding regulator

A welding regulator is also going to be needed for mig welding so that it can deliver the shielding gas to the welding puddle.

When you are mig welding with gas you need to somehow have the shielding gas come out of the bottle smoothly to welding arc.

A bottle of gas is under huge amounts of pressure. If you were to simply hook up a hose without a regulator the gas would just whoosh out in about ten seconds, and it would probably blow out the welding arc. A welding gas regulator is designed to "regulate" the flow of gas at a set level. This is so that you can lower the pressure down to a useable level.

It will be adjustable so that you can select how much gas you want to flow. This is normally rated in liters per minute or cubic feet per hour. It is just like the gas regulator on a BBQ gas bottle, except these welding ones will have a couple gauges on them.

Now on a BBQ gas bottle the regulators are preset from the factory to deliver as set amount of cooking gas to the burners and that's it. But when you're mig welding you often need to adjust the gas flow rates to higher or lower amounts depending on what you are doing. Welding regulators have an adjustable flow rate which can be easily changed by twisting a knob one way or the other. Most mig welding regulators will have two gauges. One gauge will show the welding gas flow rate and the other will show the gas bottle pressure. The gas bottle pressure reading will let you know how much gas you have left the bottle. As the gas is used the pressure inside will drop and this will show on the gauge. This will give you an idea on how much gas you have left.

Gas flow rates will be different for each mig welding process. Factors that influence shielding gas flow rates are wire thickness and welding amperage, so the thicker the metal the more gas you need. Also what type of metal you are welding such as mild steel or aluminum etc. You can also get more accurate flow meters that have a little plastic ball that floats up and down in the gas flow inside the gauge. These are much more accurate than a normal type welding gas regulator, but are not always used for mig welding, they seem to be used more so for tig welding.

Broken Welding Regulator

How about this.  Here are some photos of a broken welding regulator.  The thing has clean snapped off! 

What happend was the bottle of welding gas was sitting next to a profile cutting machine.  It was one of those optical eye trace cutting machines. 

And the gantry got caught up in the hoses and over the bottle went.  Snapping it clean off.

Lucky the bottle was not.

a) being used and turned on

b) an oxygen bottle, or fuel gas bottle

c) lucky the machine was not flame cutting at the time

d) lucky the operator did not have a smoke in his mouth if it was oxygen in the bottle.

It was only a spare mig welding gas bottle that had been put there out of the way of other things.  Could have been a pretty bad situation if it was flamable gas and the machine was cutting.  Or really, if anyone nearby was welding.

Follow on and read up about mig welder parts.