Material supply system

A gas supply and dispensing system, comprising:

• an array of at least two gas storage and dispensing vessels arranged for sequential on-stream dispensing involving crossover from a first one or more on-stream vessels to a first one or more standby vessels in the array, said system used to dispense gas at a preset gas flow rate;
• a manifold comprising piping and at least two valves in fluid communication with the array of vessels;
• a controller;
• and
• one or more sensors in communication with the controller, wherein said one or more sensors sense one or more predefined endpoints of the first one or more on-stream vessels thereby causing the controller to initiate auto-crossing from the first one or more on-stream vessels to the first one or more standby vessels in the array having gas therein, for subsequent dispensing of gas from said first one or more standby vessels;
• wherein the controller after sensing the one or more predefined endpoints initiates flow of gas from said first one or more standby vessels, said first one or more standby vessels thereby becoming the second one or more on-stream vessels dispensing gas concurrently with said first one or more on-stream vessels for a period prior to terminating the flow of gas from the first one or more on-stream vessels;
• wherein during said period prior to terminating the flow of the gas from the first one or more on-stream vessels, the controller increases the flow of the gas from the second one or more on-stream vessels to a flow rate that is greater than the preset gas flow rate, and then after sensing that the flow rate is above the preset flow rate, decreases the flow rate from the second one or more on-stream vessels to the preset gas flow rate.