The safest way to diminish gas pressure and control gas in welding, torch cutting and laboratory applications is by the use of a gas regulator. The high pressure in a gas cylinder is reduced by attaching a regulator to the cylinder. Normally, Gas cylinders have a PSI of 2,000 and it needs be lowered to 20-100 PSI to use with a cutting torch.

I have been asked many times in the past what the difference is between single and two stage regulators. I have found that most people think a two stage regulator has two gauges but that would be incorrect. Nearly all regulators have 2 gauges. Below are some of the differences between a single and two stage regulators.

The single stage is by far the most used and less expensive. They decrease the pressure from the cylinder to the outlet all in one step. On the other hand, the two stage does exactly as it says, reduces the cylinder pressure in a twofold process.

Most welding and cutting applications utilize Single stage regulators simply because a precise outlet delivery pressure throughout the cycle of the cylinder is not necessary. Or the delivery outlet does not require an increase in pressure as the cylinder decreases in pressure.

When the outlet delivery pressure needs to be maintained at all times, two stage regulators are usually required. Applications would include lab, gas chromatography or precision welding. For greater accuracy in delivery, the gas is regulated in two steps. The first stage is predetermined and the second is entirely adjustable to the regulator delivery range.

Most regulators have dual gauges. But remember, the gauge quantity does not determine if the regulator is single or two stage. The gauges are only used to establish the outlet delivery pressure and the quantity of gas left in the cylinder. The high pressure gauge, which is located near the inlet port is used to verify the quantity of gas remaining in cylinder. And the low pressure gauge, which is located next to the delivery port is used to measure the delivery pressure.

Single stage regulators cost between $60-$90, whereas the two stage regulators are normally twice that price and start between $140-$300. A two stage may not be required for most home hobbyist applications. So keep your money in your pocket! Hopefully you now have some useful information to aid in your regulator purchase.