Chapter 7 N40475 Thread details of the connections on the engines for fuel pipes • Fuel feed - 11/16” ORFS • Fuel return - 11/16” ORFS It is strongly recommended that the flexible fuel pipes, available as an option with the engine are used, which are as follows: Fuel feed The free end of the flexible pipe has a 11/16” ORFS ended fitting, and is supplied with an connector to 1/4” NPT. Fuel return The free end of the flexible pipe has a 11/16” ORFS ended fitting, and is supplied with an connector to 1/4” NPT. Fuel tanks should have the following features: • The filler neck should be raised so that water will not enter when filling.
• The filler cap should seal effectively to prevent water entering when under way. • A vent pipe should be fitted, again in such a way as to avoid the entry of water. • The tank should have a sump or angled bottom with a drain tap so that water and sediment can be removed. (This is not always possible). • Internal baffles may be required to prevent fuel surge. • The tank should have a removable panel to simplify cleaning. • The fuel pipe work should be as simple as possible with the minimum of valves and cross connections, so that obscure fuel feed problems are minimised. • The tank should have at least two connections; a fuel feed connection, and a fuel return connection.
Whenever possible a tank should only supply one engine, but in any case each engine should have its own fuel pipes, from tank to engine. Page 20