Patent ID: 7680399

Claim:
A method for producing and flowing vapor from a liquid, comprising: heating a vaporizer tank to substantially a first operating temperature to produce vapor from the liquid, wherein at the first operating temperature, the vapor in the vaporizer tank is substantially saturated; regulating a flow of the vapor to achieve a vapor flow rate; and controlling a fill valve to maintain a level of the liquid in the vaporizer tank between an overfill level and a minimum level; wherein heating the vaporizer tank, regulating the flow of vapor, and controlling the fill valve maintain the vaporizer tank at substantially the first operating temperature so that as the flow of vapor is regulated to achieve the vapor flow rate and the fill valve is controlled to maintain the level of the liquid in the vaporizer tank between the overfill level and the minimum level, a pressure in the vaporizer tank is maintained at a substantially constant value above approximately 500 Torr to maintain the vapor in the vaporizer tank in the substantially saturated condition.