Is There A Difference Between Single and Two Stage Regulators

Gas regulators are used in welding, torch cutting and laboratory applications. A regulator is attached to a high pressure gas cylinder to step down the psi. This is the safest way to reduce gas pressure. Gas cylinders usually have 2,000 PSI in and you must step them down to 20-100 PSI for 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.

Single stage regulators are the more popular and the less expensive of the two. Single stage regulators reduce the cylinder pressure to the outlet pressure in one step. Two stage regulators reduce the cylinder pressure in two steps.

The single stage regulators are used in most general welding and cutting applications. These applications do not require an exact outlet delivery pressure throughout the cycle of the cylinder. As the cylinder decreases in pressure the delivery outlet pressure will increase.

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 are supplied with two gauges. The number of gauges does not determine if it is a single or two stage regulator. The gauges are used to determine the outlet delivery pressure and the amount of gas remaining in the cylinder; the high pressure gauge located next to the inlet port is used to determine amount of gas remaining in cylinder. And the low pressure gauge next to the delivery port is the delivery pressure gauge.

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.