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About Life Jackets

 

A lifejacket is a type of personal flotation device designed to keep a person's airway clear of the water whether the wearer is conscious or unconscious. They are either made from two layers of bonded polyurethane to be inflated or from foam.

The inflatable lifejacket is probably the most widely used for both leisure and commercial activities, while the foam lifejacket is predominantly designed either for children, or for emergency use (such as on ferries, cruise ships etc.).

Types of inflation Life Jackets

Oral Some older lifejackets had oral inflation as their only method of inflation, normally via a one-way valve. Although intended for oral inflation, a suitable low pressure pump may be used if preferred. These lifejackets should be fully inflated before going afloat, and should be worn fully inflated until the wearer is back ashore. Although it is doubtful whether these are still in production, they may still be found in use. Modern lifejackets, inflated by means of a gas cartridge, usually if not always have oral inflation as well; this is intended for topping up if the casualty is in the water for an extended period while awaiting rescue, but may also be useful for inflating the lifejacket for test purposes to verify the integrity of the bladder.

Manual Manually inflated lifejackets are operated by pulling a string, which pushes a firing pin into the CO2 canister, inflating the lifejacket. Automatic and hydrostatic lifejackets both have a manual pull string as back up.

Automatic Automatically inflated lifejackets rely on a small pellet or bobbin, which holds back a powerful spring. When the pellet makes contact with water it dissolves very rapidly, releasing the spring, which pushes a firing pin into the gas canister.

Hydrostatic (Hammar) Hydrostatic or Hammar action lifejackets work the same way, but the pellet is protected by a case that only lets water in once it is a few centimetres below the surface. It won’t fire until fully submerged.

 

Chris Boyd- BoatStars Inc. CEO & Chief Editor

Latest from Chris Boyd- BoatStars Inc. CEO & Chief Editor

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