Choosing the Right Air Bag
Basic rule:
- Air Lift Bags for dynamic lifting
- Inflatable Buoyancy Units for static support
Air Lifting Bags (ALBs) are designed for the recovery of underwater objects that need lifting to the surface. They are also used as static buoyancy in underwater engineering as they only need a single attachment and are stable and easy to handle underwater. Their open bottom allows expanding air to vent freely during an ascent to the surface.
Inflatable Buoyancy Units (IBUs) are fully enclosed units designed to provide support on, or close to, the surface. Typical applications are vessel draft reduction and pipe pulls where multiple fixings can be pre-installed with no possibility excessive trim angles. Their limited ability to dump air through pressure relief valves (PRVs) makes them unsuitable for lifting operations.
Dedicated Buoyancy systems for pipes and cables are produced by Seaflex for the specialist contractor. See Main Menu for various applications.
As with all rules, there are exceptions to the above and for more information download:-
Seaflex Information Sheet No:- 051199 – Issue B - ‘Air Lift Bags – The basics’
For information on the behaviour of flexible buoyancy underwater download:-
Seaflex Information Sheet No. 290499 Issue B - ‘Buoyancy Change’
Download complete Seaflex Brochure
For special applications Seaflex are always available for practical advice on specific problems so please do not hesitate to contact us.
