F 250 4WD Super Duty V10-6.8L VIN Z CNG (2003)
Fuel Supply Line: Description and Operation
NATURAL GAS FUEL SYSTEM
Fuel Lines and Fittings
Fuel Line Assembly
A fuel line assembly (Figure 82) consists of flexible hose and/or stainless steel seamless tubing, end fittings and tube nuts. The hose is a
conductive polytetrafluoroethylene (PTFE) liner reinforced with a stainless steel wire braided covering. The fittings are inserted into the hose ends
and crimped into place. The stainless steel tubing contains end fittings which are brazed to the tube. There are high pressure fuel lines that are
identified by either 1/4-inch or 3/8-inch outer diameter and a low pressure fuel line identified by a 1/2-inch outer diameter. The low pressure fuel
line has a quick-connect at one end for connection to the fuel rail. The other fittings used on the natural gas vehicle to connect fuel components are
SAE O-ring face seal tube fittings. There are two end types: an O-ring face seal end and a straight thread end. On tee and elbow fittings, a washer
and a positionable nut are provided to aid in orientation of the fitting.
