Separate the meanings of life
A pressure vessel may be designed against an intended service period while replaceable components need maintenance or renewal much sooner. Warranty is a commercial commitment with its own terms. Remaining life in service depends on the actual operating history and condition. These concepts should not be collapsed into one marketing number.
State the assumptions
The SINOSEN brief describes a 20-year design-life objective. For a project, the relevant design code, pressure and temperature cycles, corrosion allowance, material selection and inspection basis must be established. Service outside the agreed envelope can change the assessment. A nominal period does not remove the need for examination or maintenance.
Consider cyclic service
A twin-vessel system repeatedly fills, pressurizes, discharges and vents. The expected number and severity of cycles are part of the engineering review. Temperature changes, supports and local details can also matter. The responsible vessel designer should determine the required analysis and records for the actual duty.
Manage life through records
Retain the design dossier, operating history, inspection findings and repair or modification records. Follow the applicable examination scheme and manufacturer instructions. If conditions change, seek a qualified reassessment. A useful website statement explains the objective and its conditions; it should not promise that every component will operate for twenty years without service or replacement.
General engineering guidance. Numerical examples are illustrative; project specifications and acceptance criteria are agreed for the actual duty.