If you are using a high-purity gas or a high-purity gas is needed in order to function in your application then you need to select the best regulator that you can get. Often the forged brass gas regulators which comes with a stainless steel diaphragm is the best alternative for a high-purity gas that is needed. It will also prevent any air contamination as well as any organic contamination that may occur. But it has an additional advantage in that it will not start to corrode as the stainless steel diaphragm will allow you to use it for a long time. There are some gases that are extremely corrosive and you need to make sure that the type of gas that you are using is used with the correct regulator. Whether you use a single-stage regulator or a two-stage regulator will depend on the varying droop or supply pressure or both that you get.