A method of conditioning natural gas in preparation for storage, involves taking an existing stream of continuously flowing natural gas flowing through a gas line (12) on its way to end users and diverting a portion of the stream of continuously flowing natural gas to a storage facility through a storage diversion line (22). The pressure of the natural gas is lowered, as is the temperature by the Joule-Thompson effect. The natural gas is passed in a single pass through a series of heat exchangers (18, 28,30, 32) prior to resuming flow through the gas line (12) at the lowered pressure. The diverted natural gas is liquefied in preparation for storage by effecting a heat exchange with the natural gas.