20t Marine Air Lift Bag High Strength Easy To Repair Safe For
Salvage Work
Description
The Marine Air Lift Bags from Hongruntong Marine are versatile,
heavy-duty buoyancy solutions designed for port construction,
underwater maintenance, and professional diving operations. Built
with multi-layer thermoplastic fabric and reinforced seams, these
underwater air lift bags provide exceptional lifting power while
remaining flexible and reliable under challenging marine
conditions.
The modular design allows multiple bags to be linked together to
achieve higher buoyancy, making them suitable for lifting large
prefabricated components, sunken vessels, or heavy equipment.
Stainless steel fittings and over-pressure relief valves ensure
secure attachment points and safe operation during inflation.
Each bag is engineered for precise buoyancy control, maintaining
stability even in dynamic port environments with tidal fluctuations
and strong currents. Their foldable and lightweight construction
ensures easy transportation, rapid deployment, and repeated use,
making them ideal for repetitive port construction tasks, fender
installation, and diver-assisted salvage operations.
Designed for capacities ranging from 1 ton to 50 tons, Hongruntong
Marine’s air lift bags meet the requirements of commercial harbors,
private ports, and offshore docks. Compatible with standard diving
air systems and compressors, they offer both safety and operational
efficiency for underwater engineers, port contractors, and
professional diving teams.
Case Study — Port Fender Installation, Rotterdam
In 2022, a Dutch marine construction contractor faced the task of
installing new floating fenders at Rotterdam Port. Each fender
panel weighed over 2 tons and required precise underwater
positioning to align with existing mooring structures. Conventional
lifting equipment proved cumbersome and slow, risking operational
delays.
Hongruntong Marine supplied six 8-ton Marine Air Lift Bags,
strategically placed under the fender panels. Divers connected the
lift bags using stainless steel shackles and reinforced straps. The
integrated multi-valve inflation system allowed the operators to
adjust buoyancy gradually, achieving millimeter-level control over
fender placement.
During the operation, tidal currents and minor underwater
obstructions posed challenges. The reinforced seams and durable
thermoplastic fabric ensured the lift bags remained stable and
intact, while the modular design allowed multiple bags to work in
unison for oversized panels. Within two days, all fenders were
installed successfully, with no damage or delays.
The contractor highlighted the air lift bags’ efficiency,
stability, and reusability, noting that they significantly reduced
labor intensity and enhanced operational safety compared to
traditional lifting methods. The project demonstrated the
effectiveness of Hongruntong Marine’s air lift bags in precise port
construction and diving-assisted operations.
Specifications
| Product Name | Underwater Air Lift Bags |
| Raw Material | Top-Notch PVC Coating Fabric |
| Type | Parachute |
| Size | 500kg, 1000kg, 5000kg 10000kg,etc |
| Thickness | 0.4-1.2mm, or as request |
| 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 +/- 0.2 mm on thickness +/- 0 to +3mm on width +/- 0 to +3mm on length |
| Model | Lifting Capacity | Dimensions | Appr. Weight |
| Parachute | [kg] | [lbs] | [mm] | [kg] |
| HM-P01 | 200 | 441 | 800 | 5 |
| HM-P02 | 500 | 1,103 | 1,000 | 8 |
| HM-P03 | 1,000 | 2,205 | 1,300 | 11 |
| HM-P04 | 2,000 | 4,410 | 1,600 | 20 |
| HM-P05 | 4,000 | 8,820 | 2,000 | 50 |
| HM-P06 | 6,000 | 13,230 | 2,300 | 66 |
| HM-P07 | 8,000 | 17,640 | 2,500 | 75 |
| HM-P08 | 10,000 | 22,050 | 2,700 | 80 |
| HM-P09 | 15,000 | 33,075 | 3,100 | 110 |
| HM-P10 | 20,000 | 44,100 | 3,400 | 130 |
| HM-P11 | 30,000 | 66,150 | 3,900 | 170 |
| HM-P12 | 50,000 | 110,250 | 4,600 | 220 |
| HM-P13 | 70,000 | 154,350 | 5,200 | 310 |
| HM-P14 | 100,000 | 220,500 | 5,800 | 450 |
| HM-P15 | 150,000 | 330,750 | 6,600 | 660 |
| HM-P16 | 200,000 | 441,000 | 7,300 | 900 |
| *Note: Other sizes can be customized according to the requirements. |
Features
Heavy Duty Thermoplastic Fabric
Constructed from multi-layer thermoplastic polymer, the Marine Air
Lift Bags offer superior durability, puncture resistance, and
flexibility. Reinforced seams ensure structural integrity under
repeated use, even in abrasive environments like rocky seabeds and
industrial port waters. The fabric is resistant to UV exposure,
saltwater corrosion, and petroleum-based substances, ensuring long
service life in port and diving applications.
Corrosion Resistant Stainless Steel Fittings
All attachment points, D-rings, and shackles are made from 316L
stainless steel, providing excellent corrosion resistance and
long-term reliability. These fittings allow secure connections to
heavy underwater equipment and ensure stable load distribution
during lifting or positioning tasks.
Modular and Scalable Design
Multiple lift bags can be connected using integrated straps and
valves, allowing scalable buoyancy for larger objects. Modular
design simplifies handling of oversized loads, and foldable
construction ensures easy storage and transport. This feature is
especially useful for repetitive port construction or maintenance
tasks requiring flexible lifting configurations.
Enhanced Safety and Inflation Control
Equipped with dual air valves and over-pressure relief systems,
each bag allows precise buoyancy adjustments. Divers or operators
can inflate or deflate in controlled increments, preventing sudden
surges and ensuring safe lifting of sensitive equipment. The air
lift bags are compatible with standard scuba tanks, offshore
compressors, and diving air supply systems.
Applications
Harbor and Port Construction
Ideal for lifting and positioning large fenders, caissons, and
prefabricated concrete or steel components. Ensures stability
during installation even in tidal currents or turbulent port
waters.
Diving and Salvage Operations
Supports professional divers in recovering sunken equipment,
vehicles, or containers. Provides adjustable buoyancy for safe and
controlled lift operations.
Shipyard and Dock Maintenance
Useful for hull inspections, underwater cleaning, and component
replacement. Enables precise positioning and safe handling of
equipment in confined port or shipyard areas.
Why Choose Hongruntong Marine
Advanced Manufacturing Capabilities
Hongruntong Marine utilizes CNC cutting, heat-welding, and
automated quality control systems to produce air lift bags with
consistent thickness, seam strength, and airtight integrity. This
ensures every unit meets international offshore and diving
standards.
Strict Quality Control
Every Marine Air Lift Bag undergoes hydrostatic testing and
pressure verification prior to shipment. ISO 9001 certification
guarantees reliable performance and operational safety in
high-demand environments, from busy commercial ports to offshore
docks.
Global Support and Logistics
Hongruntong provides worldwide technical support, on-site guidance,
and spare parts supply. Warehouses in key locations such as
Qingdao, Singapore, and Rotterdam ensure rapid delivery and minimal
project downtime.
Comprehensive Technical Service
From initial design consultation to installation guidance and
post-project maintenance, our engineering team offers full
lifecycle support. This ensures optimal performance, enhanced
safety, and extended service life of all deployed lift bags.
FAQ
1. What buoyancy capacities are available?
From 1 ton to 50 tons, with customized sizes for specific port or
diving applications.
2. Can these lift bags be used in saltwater and port environments?
Yes, the multi-layer thermoplastic fabric and stainless steel
fittings resist saltwater corrosion, UV exposure, and chemical
contact.
3. Are field repairs possible?
Yes, each bag includes patch kits and tools for minor on-site
repairs, allowing immediate operational recovery.
4. Are these air lift bags compatible with standard diving
equipment?
Yes, compatible with scuba tanks, offshore compressors, and
professional diving air supply systems.
5. Do you provide OEM branding or custom specifications?
Yes, logos, serial numbers, and tailored configurations are
available for bulk orders.
