Auto-switching system for switch-over of gas storage and dispensing vessels in a multi-vessel array

A gas storage and dispensing system, including multi-vessel arrays of gas dispensing vessels that require successive change-over to provide ongoing supply of gas to a gas-consuming process, with a pump coupled in gas flow communication with the array. The system is provided with capability for time delay auto-switchover sequencing of the switchover operation in which an endpoint limit sensing of an on-stream gas dispensing vessel is responsively followed by termination of gas flow to the pump, inactivation of the pump, autoswitching of vessels, reinitiation of gas flow to the pump and reactivation of the pump. The system minimizes the occurrence of pressure spikes at the pump outlet in response to pressure variation at the pump inlet incident to switchover of gas supply from one vessel to another in the multi-vessel array.