USPS Compass

Protect your inflatable PFD so it will protect you

Inflatable PFDBoaters who prefer inflatable personal flotation devices to Type III life jackets often feel that their comfort far outweighs their added expense. However, many may not know how to properly maintain these effective safety devices.

Many U.S. Coast Guard-approved inflatable PFDs are activated by a Halkey-Roberts automatic inflating mechanism with a 33- or 38-gram carbon dioxide cylinder and round chemical inflator bobbin.

The bobbin dissolves when immersed in liquid. This permits a spring-loaded firing pin to puncture the carbon dioxide cylinder, providing 35 pounds of buoyancy to the PFD in about three seconds.

If the PFD does not automatically inflate, the wearer can manually puncture the carbon dioxide cylinder by pulling the attached lanyard. If this fails, the user can inflate the PFD by mouth using the tube on the upper left side of the inner PFD.

Before donning an inflatable PFD, check that the mechanism is packed in accordance with the owner’s manual and that a fully charged carbon dioxide cylinder is in place.

The bobbin only fits into the holder one way. To prevent the cylinder from being punctured, ensure that the holder is completely screwed down before screwing in the carbon dioxide cylinder. When the bobbin holder is properly secured, the firing pin retracts, and a green indicator is visible. If you see a red indicator, something is amiss with the bobbin, or the holder is not screwed down all the way. If the mechanism has no bobbin holder, the PFD can only be inflated manually.

Some models may have a “pill”-activated mechanism and/or a bayonet tip cylinder that requires a one-eighth turn clockwise to a full stop to secure it.

Be particularly careful when inserting carbon dioxide cylinders with bayonet tips. If the carbon dioxide cylinder has not been turned, the mechanism is supposed to eject it. Sometimes you can get a false positive green indicator by pushing the cylinder into the mechanism without turning it. If the cylinder has not been fully turned and secured in place, the PFD will not inflate.

If an automatic inflating PFD mechanism is accidentally activated by moisture, all parts of the bobbin compartment must be thoroughly dried before you insert a new bobbin. Rearming a wet automatic inflating mechanism will cause the bobbin to dissolve and the PFD to inflate.

If you need to immediately rearm an automatic inflatable PFD, you can use a hair dryer to dry the compartment and place the PFD in the hot sun to remove all moisture.

With no bobbin to dissolve, a manual inflatable PFD can be rearmed immediately.

inflator bobbinWhen inspecting an inflator bobbin, make sure the “ridges” are still evident, the bobbin is not cracked and the white fill portion is not discolored. The date on the bobbin’s side is the date of manufacture, not the expiration.

In extreme weather, the chemical bobbin may deteriorate in less than 30 days. However, most of us don’t operate under those conditions, and the bobbins that come in PFD rearm kits can last years.

When purchasing a rearm kit, ensure the kit is specified for your particular PFD model. PFD model numbers can be found on the inner side near the “U.S. Coast Guard Approved” statement. Always use a correctly sized carbon dioxide cylinder. This is particularly important when rearming belt-pack PFDs, which use a smaller cylinder.

With the advent of hydrostatic inflatables that require no inflator maintenance for five years, PFD technology is improving, but periodic preventive maintenance can still save your life.

For additional information about safety recalls and flotation devices, check the Coast Guard Office of Boating Safety website or contact me with questions or comments.

–Stu Soffer
U.S. Coast Guard Auxiliary National Marketing Group

Back to top | Compass home

Privacy policy | Contact Compass staff | USPS website | Archived issues

© 2007 United States Power Squadrons. All rights reserved.