Abstract: The invention is directed to a process for providing a gas having a minimum pressure and a composition that includes a major component to an end application, said process comprising the following steps:a) providing a first gas having said major component in a first concentration to said end application;b) providing means for measuring the pressure of said first gas being delivered to said end application;c) providing a second gas having a second concentration of said major component of said first gas which exceeds said first concentration;d) providing a third gas having a third concentration of said major component of said first gas which is less than said first concentration;e) providing means for mixing said second and said third gases so as to produce a fourth gas at at least said minimum pressure and which has said major component in a fourth concentration; wherein,f) when said means for measuring the pressure of said first gas to be received at said end application detects a deficiency with respect to sa