What is a battery limit and what are the considerations for battery limit conditions?

Battery limit defines the boundary of a process unit for design purposes. Battery limit conditions specify stream parameters at the boundary: composition, flow rate, temperature, pressure, and phase. Considerations: Coordination - agree conditions with upstream/downstream units early. Margin - include margin for variations (typically 10% on flow). Specifications - clearly state guaranteed vs. expected values. Turndown - specify range of acceptable conditions. Utilities - define available utility conditions (steam pressure, cooling water temperature). Quality - specify impurity limits. Documentation - battery limit conditions appear on PFD and in process description. Changes to battery limits can have significant project impact, so establish and freeze early in design.