All compressed gases are dangerous, some more than others, so the correctly choosing Welding Gas Regulators is essential.
Gas Regulators vary in construction, depending on the gas they’re intended for. Probably the most obvious difference is the screw threads.
Regulators for combustible gases (Acetylene, Propane, Propylene etc), usually have Left Hand Threads. The left hand thread is indicated by little cuts in the flats of the Hexagon.
Regulators for non combustible gases (Oxygen, Argon, Co2 etc), usually have Right hand Threads and as such do not have the cuts on the Hexagon.
Another important difference can be the material used to manufacture internal components.
For example, internal Acetylene Regulator components are manufactured from different material to Propane Regulators. It’s therefore important that the correct regulator is used as failure to do so can be extremely dangerous.
In the example outlined above, Propane will corrode the internal components of an Acetylene Regulator, inevitably leading to failure and leaking!
So when choosing welding gas regulators, ALWAYS select the correct regulator for the gas!
I’ve written a separate article on the Difference between Single and Multi Stage Regulators
I’ve also produced a Video
The most common type of Oxygen Regulator has a 0-10 bar outlet. However, as Gas Welding Torches typically only require around 0.2 bar, a Regulator capable of delivering up to 10 bar is going to be difficult to adjust accurately at such a low pressure.
To overcome this, 0-4 bar Oxygen Regulators are also available. These are much easier to adjust at the low pressures required for most Gas Welding & Brazing torches. Even Cutting Guns can be used with nozzles up to 1/16″.
0-10 bar are for where larger Nozzles are going to be used.
I would also recommend not considering an Oxygen or Argon regulator with less than a 300 bar input rating as 300 bar cylinders are becoming more common and are likely to become the norm in future.
Acetylene becomes unstable and explosive if compressed to a high pressure. Because of this, Acetylene is dissolved in a special material.
Because of the low pressure nature of Acetylene cylinders, the Gas Regulator for Acetylene has a different internal set up.
Most Acetylene Regulators have a maximum delivery pressure of 1.5 bar.
As discussed earlier, Acetylene and Propane Regulators should never be used with any other gas than that which they are designed for, although Propane Regulators can be used for Propylene, which is made up of around 50% Propane.
Argon Gas Regulators are much the same as Oxygen Regulators. However, a key thing to look out for is the Delivery Gauge (usually on the Right).
On an Oxygen Regulator the delivery Gauge normally shows Pressure in Psi and Bar. Argon Regulators normally show Gas Flow Rate in Litres Per Minute and Cubic Feet Per Hour.
It’s important to make sure the Delivery Gauge reads Flow Rate as most Mig and Tig Welders will quote a recommended delivery in Litres per Minute.
An Argon Regulator should also be used for Argon/Co2 Mixed gases.
Most of a Co2 Regulator is the same as an Argon Regulator.
The one BIG difference is the Cylinder Fitting, which is Female.
All the other Regulators we have discussed have a Male thread to go into a Female Fitting on the cylinder. Co2 Cylinders have a Male thread, so the Regulator has to have a Female fitting.
Regulators for Disposable Gas Cylinders do the same job as their refillable cylinder counterparts, except the fitting onto the Cylinder is completely different.
Disposable Cylinders are filled to a lower pressure.
For these reasons, Disposable Cylinder Regulators are not compatible with refillable cylinders.
Correctly choosing welding gas regulators is important as pressurised gas cylinders can be dangerous.
But as long as care is taken to choose good quality and the right specification/type for the gas you’re going to be using, all should be well.
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