Underwater Air Lift Bag with 100kg to 60 tons Lifting Capacity Made of Superior PVC Coating Fabric and IMCA-D-016 Standard
The cylindrical Underwater Air Lift Bag is a specialized buoyancy solution engineered for offshore construction, subsea installation, and heavy-duty marine lifting operations. Manufactured using high-tenacity synthetic polyester fabric reinforced with multiple layers of abrasion-resistant elastomer coating, ensuring exceptional durability in aggressive marine environments.
The material structure provides superior resistance to saltwater corrosion, ultraviolet radiation, hydrostatic pressure, and temperature fluctuations ranging from -30°C to +70°C. The cylindrical design delivers uniform buoyancy distribution and improved vertical lift efficiency, minimizing lateral movement during operation.
In a large-scale offshore pipeline installation project in the Persian Gulf, Hongruntong cylindrical underwater air lift bags were deployed along multiple sections of the pipeline to provide controlled buoyancy. By carefully adjusting internal air pressure, the pipeline was gradually lifted, aligned, and stabilized during installation.
This method minimized seabed friction and prevented structural stress on the pipeline. The use of air lift bags reduced dependence on heavy-lift vessels and shortened the installation timeline by approximately 38%, while significantly decreasing diver workload and improving operational safety.


| Product Name | Underwater Air Lift Bags |
| Raw Material | Superior PVC Coating Fabric |
| Type | Cylindrical |
| Size | 500kg, 1000kg, 5000kg, 10000kg, etc |
| Thickness | 0.4mm-2.5mm, or as requested |
| Color | Yellow, Blue, Black, etc |
| Density | 0.33-0.9g/cm³ |
| Safety Factor | 7:1 |
| Accessories | Valve, Inflatable Tube, Repair Material |
| OEM | Welcome |
| Warranty | 3 Years |
| Tolerances | ±0.03 on densities, ±0.2mm on thickness, ±0 to +3mm on width, ±0 to +3mm on length |
| Model | Buoyancy (kg) | Buoyancy (lbs) | Diameter (mm) | Length (mm) | Approx. Weight (kg) |
|---|---|---|---|---|---|
| HM-C01 | 200 | 441 | 500 | 1,000 | 5 |
| HM-C02 | 500 | 1,103 | 800 | 1,000 | 8 |
| HM-C03 | 1,000 | 2,205 | 1,000 | 1,500 | 11 |
| HM-C04 | 2,000 | 4,410 | 1,300 | 1,500 | 20 |
| HM-C05 | 4,000 | 8,820 | 1,600 | 2,000 | 50 |
| HM-C06 | 6,000 | 13,230 | 2,000 | 2,000 | 66 |
| HM-C07 | 8,000 | 17,640 | 2,000 | 2,600 | 75 |
| HM-C08 | 10,000 | 22,050 | 2,400 | 2,400 | 80 |
| HM-C09 | 15,000 | 33,075 | 2,600 | 3,000 | 110 |
| HM-C10 | 20,000 | 44,100 | 3,000 | 3,000 | 130 |
| HM-C11 | 30,000 | 66,150 | 3,000 | 4,500 | 170 |
| HM-C12 | 50,000 | 110,250 | 4,000 | 4,000 | 220 |
| HM-C13 | 70,000 | 154,350 | 4,000 | 5,700 | 310 |
| HM-C14 | 100,000 | 220,500 | 4,000 | 8,000 | 450 |
| HM-C15 | 150,000 | 330,750 | 5,000 | 8,000 | 660 |
| HM-C16 | 200,000 | 441,000 | 5,000 | 10,000 | 900 |
Note: Other sizes can be customized according to requirements.
- Extreme Load Capacity with Reinforced Structural Design: Multi-layer load-bearing structure combining high-tensile fabric and reinforced webbing belts for excellent load distribution and minimal deformation under high pressure.
- Superior Resistance to Harsh Marine Environments: Advanced elastomer compounds provide exceptional resistance to seawater corrosion, UV exposure, and chemical degradation across wide temperature ranges.
- Precision Buoyancy Control with Advanced Valve System: High-performance air valves with rapid inflation ports and automatic pressure relief valves for safe, controlled lifting operations.
- Flexible Deployment and Modular Configuration: Lightweight, foldable design allows easy transportation, storage, and rapid deployment with modular configuration capabilities.
- Offshore Pipeline Installation and Alignment
- Subsea Module Installation and Positioning
- Marine Salvage and Emergency Recovery
- Extensive Offshore Project Experience: Proven track record in supplying buoyancy solutions for offshore oil & gas, marine construction, and subsea engineering projects worldwide.
- Advanced Material Engineering and Manufacturing Technology: Utilization of high-performance synthetic fabrics and advanced coating technologies for superior durability and performance.
- Comprehensive Customization Capabilities: Fully customized solutions based on project requirements including lifting capacity, dimensions, and reinforcement design.
- Reliable After-Sales Support and Technical Assistance: Dedicated technical team providing detailed guidance on installation, operation, and maintenance with quick response support.
- What is the maximum lifting capacity available? The bags can be customized up to 300 tons or more depending on project requirements.
- Are the bags suitable for deep offshore use? Yes, they are designed to withstand hydrostatic pressure and perform reliably at depths up to 50 meters or more.
- Can the bags be reused multiple times? Yes, with proper handling and maintenance, they can be reused for numerous cycles without performance loss.
- How is buoyancy controlled during operation? Through high-precision air valves and pressure relief systems that allow gradual inflation and deflation.
- What are the storage and maintenance requirements? Bags should be cleaned after use, dried thoroughly, and stored in a cool, shaded environment away from sharp objects.




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