The statutory safe service life of gas storage tanks
According to the Safety Supervision Regulations for Stationary Pressure Vessels (TSG 21), gas storage tanks, classified as Class II or Class III pressure vessels, typically have a design life of 10 to 20 years. This service life is explicitly specified by the manufacturer in the design documentation and is indicated on the nameplate and in the accompanying factory data.
TSG 21 Requirements for Periodic Inspection
After being put into service, the gas storage tank must strictly adhere to the periodic inspection intervals specified in TSG 21: the initial inspection shall generally be conducted within three years; thereafter, depending on its safety condition, the characteristics of the contained medium, and the operating environment, a comprehensive inspection shall be carried out every three to six years. Tanks that are not inspected on schedule or that fail inspection shall not be put back into service.
Key factors affecting actual lifespan
- Corrosivity of the working medium (e.g., oil-containing, water-containing, sulfur‑containing gases)
- Frequent start-stop cycles and pressure fluctuation amplitude
- Ambient Temperature and Humidity, as well as Rust-Prevention Measures
- Has overpressure, overheating, or abnormal vibration occurred?
Prerequisites for Extending Safe Use
For gas storage tanks that have exceeded their design service life, continued operation is permitted only after a safety assessment and fitness-for-service evaluation have been conducted by a qualified professional organization, and the inspection interval has been reassessed. Any extension of the tank’s service life is strictly contingent upon passing a periodic inspection; self‑imposed extensions are prohibited.