AUTOMATIC VENTING OF REFILLABLE BULK LIQUID CANISTERS

摘要

Methods, systems and apparatus for automatically maintaining a pressure differential for the continuous delivery of a liquid to semiconductor manufacturing equipment. A refillable bulk liquid delivery system includes a plurality of canisters residing along a liquid flow path, whereby an over pressure is detected within at least one of the canisters. The over pressure may be detected using an automatic venting circuit or a programmable logic controller programmed for detecting such over pressures. The over pressure is then exhausted by removing excess pressure from the canister through a venting valve to maintain a Delta pressure across the canisters for continuously delivering the liquid along the liquid flow path.