Underwater Air Lift Bags

Underwater Air Lift Bags for Sale

Underwater Air Lifting Bags (Buoyancy Salvage bag) are inflatable buoyancy devices made from high-strength flexible materials. By injecting compressed air into the bag, they generate positive buoyancy, allowing for the controlled lifting, floating, or repositioning of submerged objects. Compared to traditional metal lifting systems, lifting bags offer significant advantages such as lightweight construction, flexible operation, reusability, and high safety performance. They are essential tools in underwater engineering, salvage operations, emergency rescue, and diving support.

These lifting bags are widely used in diverse underwater applications, including shipwreck salvage, subsea equipment handling, underwater construction, marine accident recovery, dam inspections, pipeline buoyancy support, and more.

Open Bottom Buoyancy Bags – Parachute-Type Lifting Bags

Designed with an open-bottom, parachute-style configuration, typically cone-shaped or funnel-shaped. The top of the bag is equipped with high-strength lifting straps or shackles for secure attachment, along with an air release line for dynamic buoyancy control. This structure allows air to vent automatically during ascent, enabling operators to safely and accurately adjust the lift force in real time.

• Load Range: Available in lifting capacities from 100 kg up to 50 tons. For larger or irregularly shaped underwater objects, multiple bags can be combined to provide synchronized buoyancy, making them suitable for raising sunken vessels, submerged structures, or long pipeline sections.
• Typical Applications: Ideal for standard underwater lifting tasks such as diver-assisted operations, light to medium-weight salvage, tool or equipment retrieval, emergency floatation, and underwater positioning.

Open Bottom Lifting Bags Advantages:

1. Quick deployment and retrieval
2. Excellent dynamic buoyancy control
3. Reusable and diver-friendly
4. Automatic air venting reduces ascent risk

Enclosed Lifting Buoyancy Bags

Fully enclosed, sealed design in spherical, cylindrical, or rectangular shapes. Made from high-strength coated fabrics, these bags are designed to maintain a stable internal pressure once inflated and sealed. Unlike open-bottom types, they do not release air during ascent, which allows for more consistent and predictable lifting.

• Technical Specifications: Engineered for use in deeper water environments, withstanding hydrostatic pressures at depths of 30 meters or more. The materials are chemically resistant and can safely contact oil, seawater, and various industrial chemicals without degrading, making them ideal for sensitive or harsh environments.
• Typical Applications: Used in deep-water lifting tasks, long-term buoyancy support, oil pipeline suspension, subsea cable floating, and operations in environmentally sensitive zones such as chemical spill areas or polluted ports

Enclosed Lifting Buoyancy Bag Advantages:

1. Stable, constant buoyancy for static or long-duration support
2. High pressure resistance, ideal for deep-sea operations
3. Fully sealed to prevent contamination or leakage
4. Chemically resistant and highly durable