Key Considerations for Spherical Tank Maintenance and Upkeep: Ensuring Safe Operation Through Four Core Dimensions

Key Considerations for Spherical Tank Maintenance and Upkeep: Ensuring Safe Operation Through Four Core Dimensions

As core equipment for high-pressure medium storage, spherical tank maintenance must focus on safety risk points. Control measures should be implemented from four aspects: safety accessories, anti-corrosion and thermal insulation, regular inspection and testing, and foundation and structure, to prevent accidents such as leakage and rupture.

Maintenance of safety accessories is the top priority. Safety valves require manual verification once a quarter and offline verification by a third party annually, ensuring the deviation of the set pressure does not exceed ±1%. Pressure gauges should be calibrated monthly; products with an accuracy class of ≥1.6 should be selected, and any stuck pointer requires immediate replacement. Emergency shut-off valves need no-load debugging once a week to check the valve opening and closing response time (which should be ≤10s), ensuring rapid shut-off in case of medium leakage. Daily operation records of accessories must be maintained, with verification/calibration dates marked to avoid overdue use.

Anti-corrosion and thermal insulation management requires different focuses for internal and external surfaces. The external coating should be inspected every six months. If blistering or peeling occurs (area exceeding 0.1㎡), sandblasting (pressure 0.4-0.6MPa) should be used followed by touch-up with anti-corrosion paint; weather-resistant fluorocarbon paint is preferred for outdoor spherical tanks. For internal anti-corrosion linings (such as epoxy resin linings), penetrant testing (PT) should be conducted annually to check for pinholes, and any leakage found requires immediate local repair. For low-temperature storage spherical tanks (e.g., liquefied natural gas tanks), the thermal insulation layer should be inspected monthly. If condensation occurs, supplementary polyurethane insulation materials should be added promptly to keep the tank wall temperature within the designed range.

Regular inspection and testing cannot be overlooked. Wall thickness testing should be performed annually using ultrasonic testing (UT) to measure key parts of the tank wall. When wall thickness reduction exceeds 10% of the designed value, strength evaluation is required. Non-destructive testing of welds should be carried out every three years, focusing on welds at the connection between the equatorial belt and support columns; any cracks found require immediate grinding and repair welding. In addition, an air tightness test should be conducted every six months: maintain a constant pressure of 0.2MPa for 30 minutes, and apply soapy water to the welds—no bubbles indicate qualification.

Foundation and structure inspection requires long-term attention. The verticality of support columns should be checked monthly; adjust gaskets when the deviation exceeds 1‰. Foundation settlement should be inspected quarterly, and the uneven settlement of the tank bottom measured with a level gauge—foundation reinforcement is necessary when settlement exceeds 50mm. After strong winds or heavy rains, immediately inspect the tank top guardrails and platform connection bolts, and tighten any loose bolts promptly to prevent structural instability and safety accidents.