Modified vacuum actuated valve assembly and sealing mechanism for improved flow stability for fluids dispensed from storage and delivery systems below atmospheric pressure

摘要

A modified vacuum-actuated valve assembly and sealing mechanism are provided for improved sub-atmospheric pressure flow stability featuring absence of delivery pressure spikes and flow variations. The valve assembly includes a non-stationary thermoplastic sheet and a stabber. The stabbard is characterized by an upper portion having a circular periphery that is designed to engage and disengage mechanically with the inner sealing surface of the thermoplastic sheet. The sealing surface is coined to remove surface irregularities contained within the sealing surface, thereby creating a relatively smooth coined mated inner sealing surface for the circular top portion of the stabber. The valve assembly also includes a modified bellows capable of fine tuning the delivery pressure of the valve assembly.