How should vessel compatibility be specified for commercial heating elements?

Vessel compatibility should be derived from the duty rather than taken straight from a catalog. Work back from the medium, actual charge capacity and process temperature: match the bend radius and mounting height to the vessel base, verify the immersed surface load, then select sheath diameter, material and watt density, while leaving clearance for cleaning and removal and allowing for ingress protection and sensor placement. During the trial, log multi-point base temperature spread and the heat-up curve, not total time alone. Freeze drawing revision, tolerances, electrical data and measured spread at acceptance; a different vessel always requires recalculation, never direct substitution of the old specification.