This patented Airgas® two-stage Smart Indicating Regulator (SIR™) provides accurate pressure control while maintaining gas purity for gases 99.9999% pure or better. The two-stage SIR safeguards the system from contaminates that normally enter the gas stream during cylinder change out. The two-stage SIR regulator safeguards the gas stream and process if a lower grade of gas is connected to the system or if there is a purity issue with the gas. SIR regulators provide a visual indication if leaks have developed downstream from the regulator.

The purifier turns color if there is a problem in the gas stream. When the purifier changes color from the top down, it is removing impurities in the gas stream. These impurities may be from gas that is less than 99.9999% pure or from contaminants that entered the gas stream during cylinder change out. If the purifier turns color from the bottom up, the system has a leak downstream of the regulator. When the entire purifier has changed color, it simply needs to be replaced.

The Airgas two-stage SIR regulator, with the block-and-vent valve assembly incorporated into the inlet, will completely contain and remove all contaminants from entering the gas stream that occur during cylinder change out. The inlet assembly has a CGA nipple with an integral check valve. This check valve prevents mass contaminates from entering the regulator. The small amount of air and moisture introduced during cylinder change out are trapped between the nose of the CGA and the inside of the cylinder valve. The vent valve is specially designed to create a vacuum which totally removes contaminates before they enter the process stream.

The purifier has a patented quick-change base to allow for easy change out of spent purifiers. The base has integral check valves built into the self-piercing connectors. These check valves allow the spent purifier cartridge to be changed without exposing the gas stream to contamination.

The regulator portion is specially cleaned for all analytical applications and will not generate contaminates that consume the purifier. The built-in safety relief valve protects instruments downstream, as well as the purifier, in the event of a regulator failure.