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{"title":"Boat Lift Helper Strong Load Capacity Durable Material Quick Setup","imgUrl":"https:\/\/img.chinax.com\/nimg\/9d\/5a\/9bd0a29be2c342fe0098616d6513-200x200-1\/boat_lift_helper_strong_load_capacity_durable_material_quick_setup.jpg","attrs":{"Delivery Time":"5-7 Work Days","Thickness":"0.4mm-2.5mm, or as Request","Packaging Details":"Wooden Pallets, Wooden Box","Place of Origin":"China"}}
{"title":"Buoyancy Bags High Lift Strength Tear Resistant Long Service Life","imgUrl":"https:\/\/img.chinax.com\/nimg\/d7\/1b\/4d827c351b840a66046b9e260365-200x200-1\/buoyancy_bags_high_lift_strength_tear_resistant_long_service_life.jpg","attrs":{"Valve":"Inflation and Pressure Release","Reinforcement":"Nylon Fabric","Thickness":"0.4mm-2.5mm, or as Request","Layers":"1-6Ply, or As Request"}}
{"title":"Inflatable Salvage Bags Marine Grade Fabric Large Capacity Corrosion Resistant","imgUrl":"https:\/\/img.chinax.com\/nimg\/f5\/b1\/57cd0d2dac9ee63a9996b36a96d1-200x200-1\/inflatable_salvage_bags_marine_grade_fabric_large_capacity_corrosion_resistant.jpg","attrs":{"Payment Terms":"L\/C, T\/T, D\/A, D\/P, Western Union, MoneyGram","Packaging Details":"Wooden Pallets, Wooden Box","Application":"Salvage Operations, Underwater Construction","Place of Origin":"China"}}
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Underwater Lift Bags: Excellent Air Sealing Property with Flexible Inflatable Design for Safe Buoyancy
Underwater Lift Bags are engineered inflatable buoyancy systems developed for controlled underwater lifting, recovery, flotation assistance, stabilization, and positioning of submerged loads. By enclosing a controlled volume of air and displacing surrounding water, the equipment generates positive buoyancy that reduces the effective submerged weight of the connected load.
Product Overview
Constructed from high-strength synthetic reinforcement fabric combined with durable rubber or elastomeric coating, these lift bags provide tensile strength and dimensional stability while protecting against abrasion, water exposure, and marine surface contact. Reinforced seams, load-bearing straps, lifting points, inflation valves, and connection components are integrated for controlled force transfer during operation.
Case Study: Temporary Buoyancy System for Offshore Structural Maintenance
An offshore maintenance contractor in the North Sea required temporary buoyancy support during replacement of a 16-tonne submerged steel service structure. The restricted working area made conventional rigid lifting frames impractical. Multiple Underwater Lift Bags were positioned at different points beneath the assembly and inflated gradually to distribute buoyancy and maintain stable attitude during initial separation and temporary flotation.
The multi-point arrangement prevented excessive rotation and allowed the offshore team to maintain controlled positioning. Once replacement work was ready, the structure was moved laterally while bags maintained temporary buoyancy. The equipment was subsequently inspected and retained for future offshore maintenance activities, demonstrating suitability for confined working areas with compact transportation benefits.
Technical Specifications
Product Name
Underwater Lift Bags
Raw Material
PVC coating fabric
Type
Cylindrical
Size
500kg, 1000kg, 5000kg, 10000kg, etc.
Thickness
0.4-1.2mm, or as requested
Color
Yellow, Blue, Black, etc.
Density
0.33-0.9g/cm³
Safety Factor
7:1
Tolerances
±0.03 on densities, ±0.2mm on thickness, ±0 to +3mm on width, ±0 to +3mm on length
Model Specifications
Model
Buoyancy (kg)
Buoyancy (lbs)
Diameter (mm)
Length (mm)
Approx. Weight (kg)
HM-ULB01
200
441
500
1,000
5
HM-ULB02
500
1,103
800
1,000
8
HM-ULB03
1,000
2,205
1,000
1,500
11
HM-ULB04
2,000
4,410
1,300
1,500
20
HM-ULB05
4,000
8,820
1,600
2,000
50
HM-ULB06
6,000
13,230
2,000
2,000
66
HM-ULB07
8,000
17,640
2,000
2,600
75
HM-ULB08
10,000
22,050
2,400
2,400
80
HM-ULB09
15,000
33,075
2,600
3,000
110
HM-ULB10
20,000
44,100
3,000
3,000
130
HM-ULB11
30,000
66,150
3,000
4,500
170
HM-ULB12
50,000
110,250
4,000
4,000
220
HM-ULB13
70,000
154,350
4,000
5,700
310
HM-ULB14
100,000
220,500
4,000
8,000
450
HM-ULB15
150,000
330,750
5,000
8,000
660
HM-ULB16
200,000
441,000
5,000
10,000
900
Note: Other sizes can be customized according to requirements.
Key Features
Reinforced Structural Integrity: High-strength synthetic reinforcement with durable coating provides tensile strength and dimensional stability for reliable underwater load support
High Wear Resistance: Rubber or elastomeric coating withstands demanding contact conditions with marine surfaces and structures
Controlled Inflation: Progressive load reduction allows operators to monitor response and maintain stability during lifting operations
Compact Transportation: Deflated condition reduces storage volume and simplifies deployment in restricted working areas
Applications
Coastal Infrastructure Maintenance: Temporary buoyancy for submerged structural frames, marine hardware, and construction components
Shipyard and Dock Engineering: Moving submerged steel components and machinery in wet docks and maintenance basins
Underwater Construction Component Handling: Installation, removal, and repositioning of submerged construction components with controlled flotation
Why Choose Hongruntong Marine
30+ Years Manufacturing Experience: Extensive background in marine product manufacturing with practical understanding of material selection and structural construction for operational reliability.
Material Selection & Reinforcement Engineering: Careful selection of reinforcement fabric, coating systems, and components balanced for strength, flexibility, and durability.
Manufacturing Control & Product Inspection: Consistent production with rigorous inspection of lifting body, straps, seams, valves, and connection areas.
Technical Support: Comprehensive support from product selection through project use, including customization for specific application requirements.
Frequently Asked Questions
Can Underwater Lift Bags be used for loads partially buried in sediment?
Yes, when properly engineered. Initial buoyancy reduces contact force before additional lifting force is applied. Seabed condition, degree of burial, and load geometry should be evaluated before deployment.
What determines the number of lifting bags required?
Quantity depends on submerged weight, required buoyancy, load dimensions, center of gravity, attachment locations, water depth, and desired load distribution. Configuration should be established through proper lifting planning.
Can equipment remain installed underwater for extended periods?
Suitability depends on project environment, material specification, operating pressure, water depth, and exposure conditions. Condition should be monitored periodically for long-term deployment.
What maintenance is required after underwater use?
Clean of sediment, allow to dry, and visually inspect body, seams, lifting straps, connection points, valves, and inflation components. Store in dry environment away from sharp objects and excessive heat.
Can lifting bags be supplied with different connection arrangements?
Yes. Connection configurations can be adapted for intended lifting method and load geometry. Provide detailed load information and connection requirements during design stage.
Company Details
Bronze Gleitlager
,
Bronze Sleeve Bushings
and
Graphite Plugged Bushings
from Quality China Factory
Business Type:
Manufacturer
Year Established:
1990
Total Annual:
5,256,780-5,593210
Employee Number:
220~360
Ecer Certification：
Verified Supplier
Hongruntong Marine is a leading marine company specializing in providing comprehensive services in the maritime industry. With a strong emphasis on quality, safety, and efficiency, we strive to meet the evolving needs of our clients.
Established in 1990, Hongruntong Ma... Hongruntong Marine is a leading marine company specializing in providing comprehensive services in the maritime industry. With a strong emphasis on quality, safety, and efficiency, we strive to meet the evolving needs of our clients.
Established in 1990, Hongruntong Ma...
