In the construction of large storage tanks, such as fixed-roof tanks, floating-roof tanks, and spherical tanks, the chain-type hydraulic jacking system plays a critical role in ensuring efficient and safe assembly. This system is particularly vital in the "inverted construction method," where the tank roof and upper wall panels are assembled first and then lifted sequentially to weld lower sections.

The chain-type hydraulic jacking system typically consists of the following key components:

• Hydraulic Jacks: Self-locking hydraulic jacks (e.g., SQD-160-100S.f type) with dual-action cylinders and clamping mechanisms, enabling stepwise lifting and stability during operations.
• Lifting Frame and Rods: These transmit force from the jacks to the tank structure. The rods are designed to withstand high loads while maintaining alignment.
• Hydraulic Control System: Includes control cabinets (e.g., BY-36 or BY-60 models), high-pressure hoses, and pumps. These regulate pressure and flow to synchronize multiple jacks.
• Stiffening Rings (Expansion Rings): Installed around the tank's inner circumference, these ensure structural integrity during lifting. They are tightened using manual jacks and connected to the tank via force-transfer plates.
• Centralized Monitoring: Sensors and cameras are often deployed to monitor lifting progress and balance, especially in large-scale projects like 100,000 m³ LNG tanks.

The system operates through a cyclic process:

1. Initial Setup: The tank base and roof are assembled first. Stiffening rings are fixed to the upper wall panels, and hydraulic jacks are evenly distributed around the tank's perimeter.
2. Lifting Phase: Hydraulic pressure drives the jacks to grip and lift the rods, raising the roof and attached wall panels. The self-locking mechanism prevents slippage during pauses.
3. Sequential Welding: After each lift, a new wall section is welded below. The jacks are then reset, and the stiffening rings are repositioned for the next cycle.
4. Precision Control: Real-time adjustments ensure even force distribution, critical for maintaining the tank's circularity and avoiding deformation.

• Safety and Efficiency: Unlike traditional "top-down" methods, the inverted approach minimizes aloft work, reducing risks and scaffolding costs.
• Scalability: Suitable for tanks ranging from 1,000 m³ to 30,000 m³, with recent advancements enabling applications in 100,000 m³ LNG tanks.
• Technical Innovations: Patented designs, such as adjustable central pulley systems, enhance lifting capacity and adaptability for complex projects like LNG tanks.

Optimizations in hydraulic jack design, such as lightweight materials and AI-driven control systems, are expected to further improve precision and load capacity. Additionally, modular components will enhance adaptability for diverse tank geometries.

The chain-type hydraulic jacking system revolutionizes storage tank construction by combining mechanical robustness with precise control. Its applications span oil, gas, chemical, and water industries, driven by continuous advancements in hydraulic technology and structural engineering.