Underwater Lift Bags
Hongruntong Marine supplies underwater lift bags, air lift bags for boats and underwater lifting bags. Professional underwater air lift bags for sale with certified quality.
Hongruntong Marine specializes in manufacturing high-performance underwater lift bags and specialized lift bag for boats systems for marine salvage and underwater operations. We offer a comprehensive range of underwater air lift bags for sale designed to provide reliable buoyancy and lifting capabilities in challenging marine environments. Our underwater air lift bags are engineered with advanced materials and robust construction to ensure safe and efficient performance. These professional underwater lifting bags solutions are ideal for vessel recovery, underwater construction, pipeline installation, and various marine salvage operations requiring precise buoyancy control.
There are 3 commonly used types of lifting bags: Cylindrical, Water Drop, Pillow.
The bags can be inserted between the bottom of the ship and the bottom of the sea to pry up the sunken ship, and can also be used to restore the buoyancy of the ship itself. Each airbags can lift more than 200 tons in the water.
Characteristics
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Wide Capacity Range: From portable 50 kg bags to heavy-duty 10,000+ kg underwater lifting bags, matched to your lift profile.
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Diver-Friendly Design: Low-profile inlet valves, robust lifting hardpoints and clear pressure markings for safe subsea handling.
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Durable Materials: High-tenacity reinforced TPU/PVC fabrics and heat-welded seams for abrasion and puncture resistance.
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Reliable Inflation System: Quick-fill low-pressure valves and over-pressure safety reliefs ensure controlled ascent.
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Pack & Deploy: Compact stowage and fast deployment—ideal when you need underwater air lift bags for sale with immediate availability.
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Versatile Use: Suitable as a lift bag for boats, salvage bags, wreck recovery, pipeline floatation, and habitat positioning.
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Certified Safety: Manufactured and batch-tested to industry lift-bag performance standards (test certificates supplied with each unit).
Applications
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Marine salvage and vessel recovery operations
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Underwater construction and installation
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Pipeline and cable laying projects
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Shipwreck recovery operations
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Harbor and port maintenance
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Emergency response and rescue operations
Structure
Specifications
| Type | Diameter | Length | Buoyancy | |
| Cylindrical | [mm] | [mm] | [ton] | [lbs] |
| HMC-1/5 | 500 | 1,000 | 0.2 | 400 |
| HMC-1/2 | 800 | 1,000 | 0.5 | 1,000 |
| HMC-1 | 1,000 | 1,500 | 1 | 2,000 |
| HMC-2 | 1,300 | 1,500 | 2 | 4,000 |
| HMC-4 | 1,600 | 2,000 | 4 | 8,000 |
| HMC-5 | 1,800 | 2,000 | 5 | 10,000 |
| HMC-6 | 2,000 | 2,000 | 6 | 12,000 |
| HMC-8 | 2,000 | 2,600 | 8 | 16,000 |
| HMC-10 | 2,400 | 2,400 | 10 | 20,000 |
| HMC-15 | 2,600 | 3,000 | 15 | 30,000 |
| HMC-20 | 3,000 | 3,000 | 20 | 40,000 |
| HMC-30 | 3,000 | 4,500 | 30 | 60,000 |
| HMC-50 | 4,000 | 4,000 | 50 | 100,000 |
| HMC-70 | 4,000 | 5,700 | 70 | 140,000 |
| HMC-100 | 4,000 | 8,000 | 100 | 200,000 |
| HMC-150 | 5,000 | 8,000 | 150 | 300,000 |
| HMC-200 | 5,000 | 10,000 | 200 | 400,000 |
| Type | Diameter | Buoyancy | |
| Water Drop | [mm] | [ton] | [lbs] |
| HMWD-1/5 | 800 | 0.2 | 400 |
| HMWD-1/2 | 1000 | 0.5 | 1000 |
| HMWD-1 | 1,300 | 1 | 2,000 |
| HMWD-2 | 1,600 | 2 | 4,000 |
| HMWD-4 | 2,000 | 4 | 8,000 |
| HMWD-5 | 2,150 | 5 | 10,000 |
| HMWD-6 | 2,300 | 6 | 12,000 |
| HMWD-8 | 2,500 | 8 | 16,000 |
| HMWD-10 | 2,700 | 10 | 20,000 |
| HMWD-15 | 3,100 | 15 | 30,000 |
| HMWD-20 | 3,400 | 20 | 40,000 |
| HMWD-30 | 3,900 | 30 | 60,000 |
| HMWD-50 | 4,600 | 50 | 100,000 |
| HMWD-70 | 5,200 | 70 | 140,000 |
| HMWD-100 | 5,800 | 100 | 200,000 |
| HMWD-150 | 6,600 | 150 | 300,000 |
| HMWD-200 | 7,300 | 200 | 400,000 |
| Type | Length | Width | Buoyancy | |
| Pillow | [mm] | [mm] | [ton] | [lbs] |
| HMPW-1/10 | 1020 | 760 | 0.1 | 220 |
| HMPW-1/4 | 1320 | 820 | 0.25 | 550 |
| HMPW-1/2 | 1,300 | 1,200 | 0.5 | 1100 |
| HMPW-1 | 1,550 | 1,420 | 1 | 2200 |
| HMPW-2 | 1,950 | 1,780 | 2 | 4400 |
| HMPW-3 | 2,900 | 1,950 | 3 | 6600 |
| HMPW-4 | 3,230 | 2,030 | 4 | 8400 |
Detailed Photos
Technical Specifications
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Materials: Reinforced TPU or PVC coated fabric; heat-welded seams.
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Capacities: 50 kg, 200 kg, 500 kg, 1,000 kg, 2,000 kg, 5,000 kg, 10,000+ kg (custom capacities on request).
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Working Pressure: Low-pressure inflation (typically 0.02–0.10 MPa) — use diver-supplied air or surface supply per procedure.
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Valve Types: Quick-fill low-pressure non-return valve; over-pressure relief valve; fill whip adaptor.
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Lifting Points: Stainless steel or composite hardpoints rated > MBL (maximum breaking load).
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Temperature Range: −40°C to +80°C (material dependent).
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Stowage Size: Folded packs for compact storage; reels or crates available for large units.
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Marking: Capacity, serial number, test date, max inflation pressure and handling instructions printed on each bag.
Exact specs, certification level and recommended rigging depend on chosen capacity and intended use — request our datasheet for project-specific guidance.
Operation & Safety Notes
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Inspect bag and valves before each use; check test/date tag.
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Calculate required buoyancy including weight of waterlogged object and safety margin.
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Use correct rigging: spreaders, bridles and rated shackles; never exceed hardpoint rated load.
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Fill slowly while monitoring ascent rate; use lift-line or taglines to control drift.
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Employ over-pressure relief procedures and gradual deflation for controlled lowering.
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Never inflate beyond rated pressure; maintain diver and vessel communication throughout operation.
(Full operation procedure and risk assessment templates provided with purchase.)
Quality Assurance & Testing
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Each underwater air lift bag is batch pressure-tested and inspected prior to shipment.
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Material traceability and manufacturing records included.
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Optional witnessed testing and third-party certification available for large-capacity units.
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Spare parts, repair kits and refurbishment programs offered to extend service life.
Why Choose Hongruntong Marine?
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Proven Track Record: Supplying underwater lifting bags and lift bag for boats solutions to commercial divers, navies and salvage companies.
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Technical Support: Engineering advice for buoyancy calculations, rigging and safe procedures.
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Custom & Off-the-Shelf: Stocked units for fast delivery plus bespoke sizes and fittings.
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Global Logistics: Competitive pricing and shipping for customers seeking underwater air lift bags for sale worldwide.
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After-Sales Care: Spare valves, repair services and inspection reminders to keep systems compliant and ready.
FAQ
Q1: What capacity lift bag do I need to lift a small boat?
A1: Calculate the boat’s displacement (fully waterlogged) and apply a safety factor (typically 1.2–1.5). Small boats commonly require 500–2,000 kg total buoyancy; contact us with boat specs for exact sizing.
Q2: Can divers inflate these bags?
A2: Yes — our bags are diver-operable with low-pressure valves; surface-supplied air or SCUBA may be used following safe inflation practices.
Q3: Do you sell underwater air lift bags for sale off the shelf?
A3: Yes — we stock common capacities and maintain ready inventory; custom capacities and larger units are made to order.
Q4: Are repair kits available?
A4: Yes — repair patches, valve spares and service kits are available to extend bag life and ensure safe operations.
Q5: How are these bags certified?
A5: Each bag is batch tested and supplied with a test certificate. For large-lift or tendered projects we can arrange third-party witnessing or additional certification per client requirements.
