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Inflatable PFD maintenance

2011 November 1

Learn to check your own PFD to ensure it will work: your life may depend on it

During the 2009 Sydney-to-Hobart Race, none of us aboard the fast-paced supermaxi wore life jackets-day or night, stormy or calm. The safety officer kept the 22 lanyard-activated inflatable vests safely stowed in a locker below deck where heavy sails were piled against the door.

We were lucky the boat reached Tasmania in one piece, but things might have gone differently, as they did for Rambler 100, which capsized after its keel snapped off during the Fastnet Race last  August. Of the 21 sailors aboard, 16 scrambled atop the overturned hull. At least two of them nearly drowned because they weren't wearing PFDs (personal flotation device). They had been below deck, off watch and resting in their bunks. The remaining five sailors washed overboard had been on deck and wearing PFDs, as required by Fastnet race rules. The PFDs kept them afloat for hours until rescue crews arrived.

Based on accounts from the scene, the PFDs functioned properly. Everyone was rescued. The outcome  was a testament to mandatory safety training and equipment maintenance. The Rambler incident highlighted a single, indisputable fact: an inflatable PFD can save your life, but only if it has been serviced and kept ready.
There are basically two kinds of Type V inflatable PFDs: manual and automatic. Most are equipped with a 33- or 38-gram metal cylinder filled with carbon dioxide. Manually-inflated PFDs require the user to pull a lanyard, which pushes a pin that punctures the cylinder and releases gas into the life vest bladder. Automatically-inflated PFDs are activated by immersion in water, or by water pressure, depending on the manufacturer and model.

For example, Mustang's HiT (hydrostatic inflator technology) relies on water pressure to activate the valve built into the life vest. Waves, rain or other sources of moisture are unlikely to arouse the pressure valve, which must be immersed four inches before it activates.

Other models depend on a pill or bobbin-a plastic ring filled with a water-soluble substance-which, when wetted, quickly dissolves and allows the spring-loaded firing pin to pierce the metal gas cylinder.

In either case-pressure valve or bobbin-the PFDs are designed to inflate if the sailor goes overboard. Should the gas cylinder fail, all inflatable life vests are equipped with an oral inflation tube. It's wise to determine which kind of PFD you are wearing because manually-activated PFDs require the lanyard be yanked. You don't want to be in the water waiting for automatic inflation if the life vest isn't so designed.

When it comes to caring for your equipment, you don't need to send your PFD back to the manufacturer for routine maintenance. Instead, familiarize yourself with the parts and their operation.

The first step in PFD maintenance is to inspect it for wear. Lay the PFD on a smooth, flat surface. Check the seams and stitching. Examine the typically heavy-duty Denier nylon material closely for rips, tears or punctures. 

Orally inflate the life vest by blowing into the tube mouthpiece.  Let it rest inflated overnight in a place with no drastic fluctuations in air temperature. The bladder should still be inflated in the morning. If not, it's time to bring the vest in for professional service.

To deflate a PFD, remove the dust cap on the oral inflation tube and reverse it. Use the underside of the attached cap to depress the valve inside the tube mouthpiece while gently pressing on the life vest. This will force out the air. Do not try to expel air from an inflated PFD without depressing the valve. It will damage the bladder.
Next, undo the Velcro tabbing and completely open the life vest. While Mustang isolates its metal cylinders inside the bladder for better comfort, West Marine models like SOSspenders allow direct access to the cartridge.
Unscrew the metal cylinder and inspect the threads for corrosion. Check the date of manufacture. Inflatable PFDs with bobbins should be rearmed with a fresh one every two years. Bobbins are usually sold in packs of 12. Pressure valves, like those found in Mustang hydrostatic vests, are good for five years before replacement.

Make sure the bobbin isn't cracked or discolored, and that ridges on its surface are still visible. It should fit snuggly into the holder before the cylinder is screwed into place. Doing so retracts the firing pin and allows the user to see the green indicator, symbolizing a PFD is successfully rearmed. If the view window shows red, it's an indication the life jacket is not properly armed. It should also be noted extreme weather, marine environments or high humidity can shorten the bobbin's lifespan.

Although most inflatable life vests use threaded cylinders, some are made with a bayonet-tip that requires a one-eighth clockwise turn to a full stop in order to secure them. When inspecting the cylinder, make sure it hasn't been pierced. If the cylinder is threaded, insert it carefully and hand tighten. Before re-inserting the cylinder, sharply tug on the firing-pin lanyard until you're certain it moves freely.

Inflatable life jackets with gas cylinders are made to inflate fully in three seconds. Once inflated, they provide about 35 pounds of buoyancy.

If the cylinder has not been pierced but leaves you guessing whether it's full, weigh it on a beam scale. It should read 33 or 38 grams, give or take two grams in either direction.

Before reassembling the life vest, blow into the oral inflation tube to be sure it's unobstructed, then replace the dust cap. Blow the whistle and inspect the short length of twine securing it to the life vest. Check the personal strobe if so equipped and replace with fresh batteries. Inspect webbing, belts, buckles and harness for wear and functionality. Adjust the life vest so that it's ready for you to wear, not your 85-pound Auntie Sue. Make sure the reflective SOLAS tape isn't peeling off. Zippers should work flawlessly, especially those providing access to the manual inflation tube, strobes or other gear.

If the life vest has a built-in harness, inspect the D-rings and other contact points thoroughly. The metal rings are all that tether you to the boat.

Buying and installing a rearm kit should not be a daunting task. Most involve following simple directions. For the Mustang with hydrostatic technology, the vest is laid flat, the cylinder pocket turned inside out, and the valve cap removed using a special key. The valve cap is discarded, as is the cylinder and the sealing ring.

A new cylinder and sealing ring are inserted inside the hole in the bladder, and a new valve cap pressed into place. The sealing ring is then turned clockwise until it locks on the valve cap. The process should take no more than 10 minutes.

Keep in mind all inflatable PFDs have advantage over traditional life jackets because they keep the wearer's head upright, reducing the risk of swallowing water. Automatically-inflated vests further increase the odds of survival because even if the wearer is struck by the boom and knocked unconscious in the water, there's no need to yank on the lanyard.

Store your inflatable PFD in a warm, dry place, out of direct sunlight. The PFD should be rinsed with fresh water after exposure to the sea. To clean it, remove the cylinder and bobbin, cap the oral inflator, and sponge all material with soapy water. Rinse, hang on plastic hanger, and allow to dry.

The next generation of inflatable PFDs are being made from high-stretch membrane fabrics, which weigh less and are more comfortable without sacrificing buoyancy.