Clean-in-place cycle (SFC)

A clean-in-place sequential function chart documents how a vessel is washed without being dismantled. The chart starts from a stable ready state, then moves through pre-rinse, caustic wash and final rinse as each phase reports completion. Keeping each phase as a separate step makes the intended valve and pump actions clear to operators, controls engineers and reviewers. It also gives a PLC programmer a direct starting point for implementation in an IEC 61131-3 environment. Add temperature, conductivity, return-flow or timeout conditions when the cleaning procedure requires them. The completed SFC is useful in a functional specification, factory acceptance test or change review because it records both the normal sequence and the signals that permit each transition.