Dynarex CGA870 All Brass Oxygen Regulator, All Brass - 0-25 LPM, Barb & 2-DISS Outlet, UPC: 616784522715, Model Number 5227 || A pressure regulator is a device, often called a pressure-reducing valve, that is intended for medical purposes and that is used to convert a medical gas pressure from a high variable pressure to a lower, more constant working pressure. This device includes mechanical oxygen regulators.