ABSTRACT
Several types of materials are commonly used in the manufacture of the fuel tank. One type is the pressed steel, often coated on the inside with lead/tin to prevent corrosion. They normally have either welded joints and seams or soldered joints (where the tin is cut and bent to shape and the seams are rolled before being soldered). Another type uses expanded synthetic rubber or flame-resistant plastic, moulded to the required shape. This gives a high resistance to damage as it will bend or distort fairly easily. It is also lighter than those made from steel and is rust proof. The tank is usually fitted with baffles (these
are partitions inside the tank) to prevent the fuel surging from side to side, especially when the tank is not full. Holes are positioned in the side or top of the tank to allow for the location of the fuel-gauge sensor unit, the supply and return pipes and the filler pipe. A coarse gauze filter is positioned over the fuel feed pipe to prevent large particles of dirt from blocking the pipe. A vent pipe is also fitted to relieve the vapour pressure and allow air to enter as fuel is drawn from the tank. The filler tube usually contains the vent pipe and the overflow pipe near to the filler cap end. No petrol vapour is allowed to pass into the atmosphere, so a non-venting filler cap is fitted; it contains a one-way valve
approach to motor vehicle
allowing air into the tank and preventing the fuel and its vapour from escaping.
