The Types of Marine Fuel Hose

Boats and other watercraft are some of the most loved recreational crafts available. However, they are also need a lot of maintenance in order to run and last for years of enjoyment. Fuel hoses are one area that will likely need replacing over the life of a boat or other watercraft. There are regulations in place that determine what kind of marine fuel hose can be used.

Testing

All lines must meet the requirements of law and regulations. Every fuel line will be marked USCG, which refers to the U.S. Coast Guard; the Coast Guard enforces laws and regulations on the water just as police enforce them on land. Marine fuel hoses are tested in two areas:

• Fire. The hoses must sustain being burned in a fire chamber for at least 2 ½ minutes.


• Leaking of gas through permeation of the fuel lines. The regulations only allow for lines that leak 100 grams or less per square meter in 24 hours or 300 grams or less per square meter in 24 hours. This is called the permeation rating.

Each hose must have clear marking declaring the type of approved hosing it is.

USCG Type A1

This hose has a permeation rating of 100 grams or less.  An A1 hose may be used for any application, but it must be used for the hose between the fuel pump and the carburetor.

USCG Type A2

This hose has a permeation rating of 300 grams. A2 hoses can be used for a vent line or a fill line.

USCG Type B1

This hose has a permeation rating of 100 grams or less.  Generally more inexpensive, B1 hoses can be used for a vent line or a fill line. B1 hoses can also be used from the fuel tank to the fuel inlet connection on the engine. B1 hose can be used as long as the hose will not release more than 5 ounces of fuel in 2 ½ minutes if cut or damaged.

USCG Type B2

This hose has a permeation rating of 300 grams, and it is generally the least expensive type of hose. B2 hoses can be used for a vent line or a fill line as long as the hose will not release more than 5 ounces of fuel in 2 ½ minutes if cut or damaged.