Pressure Regulator Basics: Single vs Dual Stage

Single Stage Regulators. 

MATHESON high purity single stage cylinder regulators are available in plated brass or stainless steel. Both have stainless steel diaphragms. Available ranges (outlet pressure) are from 0-15 psig up to 0-500 psig. 

All single stage regulators exhibit a characteristic known as cylinder pressure decay. As the cylinder is depleted, the cylinder pressure decreases. This reduces the pressure on the inlet side of the regulator, which causes an increase in the delivery pressure.

Single stage regulators are the choice when delivery pressure is not critical, when the application calls for short term flow, or when periodic re-adjustment of the delivery pressure is not a problem. 

Single stage regulators are also appropriate when using liquefied gases, such as CO2, which maintain their vapor pressure until depleted. 

All Regulators web page
Single Stage Regulators online information and shopping page

Dual Stage Regulators. 

MATHESON high purity dual stage cylinder regulators are available in plated brass or stainless steel. Both have stainless steel diaphragms. Available ranges are from 0-15 psig up to 0-500 psig pressure at the outlet. 

Dual stage regulators are essentially two single stage regulators in one body, with the first regulator supplying the second regulator. As a result, since the inlet pressure at the second stage is stabilized by the first stage, dual stage regulators do not exhibit significant pressure decay. 

Therefore, dual stage regulators are the choice when the delivery pressure of the regulator must be stable over a long period of time as the cylinder pressure decreases. A dual stage design will supply a delivery pressure that is essentially constant. 

It is important to remember that dual stage regulators are not definitively "better than" single stage regulators. The distinction between the two types boils down to how a dual stage regulator deals with pressure decay. The other advantages of dual stage design are incrementally small.

All Regulators web page
Dual Stage Regulators online information and shopping page