- Flexible fuel hose used in marine applications must meet the requirements of SAE J1527 and must be marked as such (ABYC H-24 and H-33). Flexible fuel hose for marine use is rated for specific applications using a letter – number combination. The United States Coast Guard (USCG) has designated four types of marine fuel hoses – viz., A1, A2, B1, and B2. The USCG requires fuel hose approved for marine applications to be marked “USCG Approved Type __” every twelve (12) inches – along with the date of manufacture (see photograph below of a section of USCG Approved A1 marine fuel hose which is marked fire and alcohol resistant). ABYC Sections H-24 and H-33 specifies fuel hose types and usage for gasoline and diesel fuel systems. Newer alcohol based fuels will cause older approved hoses to deteriorate and leak. Each flexible fuel hose end must be secured by a swaged sleeve, and sleeve – threaded insert, or a corrosion resistant hose clamp. Note – not all Type A hose is designed to be clamped.
Type A1 hose is for critical fuel delivery applications for both gasoline and diesel fuel products due to its good fire resistance and low permeation characteristics. 33 CFR 183 requires that A1 or A1-15 hose be used for inboard gasoline machinery fuel systems. ABYC H-33 recommends either A1 or A2 for diesel fuel applications within engine compartments. Type A1, A1-15, and A2 hose is required and or recommended for vent and fill applications. Type B1 and B2 fuel hose is also recommended for use as vent and fill hose outside the engine compartment where a break in fuel systems will not result in the discharge of not more than five (5) ounces of fuel in 2-1/2 minutes. All fuel delivery, fill, and vent hoses must be of proper specifications. The use of non-marine grade hoses, such as used in automobiles, is not recommended. G
Gasoline and diesel fuels have a profound effect on hoses. Fuel hoses should routinely wiped with a clean, dry cloth to check for excessive fuel order which could indicate leakage.