Steel fuel conveying pipe

摘要

To provide a steel fuel conveying pipe which has high resistance to corrosive fuel and maintains reliability without damaging a direct-injection engine, and connects a high-pressure pump and a direct-injection rail with each other in a gasoline direct-injection engine system, and a fuel conveying pipe suitable as a bypass pipe for coupling direct-injection rails with each other in a V-type gasoline engine. A steel fuel conveying pipe for conveying gasoline is characterized in that a Ni-plated layer is provided on the whole inner circumferential face of the fuel conveying pipe, and an anti-rust film layer composed of a Zn-plated layer and a Zn-based alloy-plated layer is further provided on the Ni-plated layer at at least one end of the fuel conveying pipe.

主权项

1. A steel fuel conveying pipe for conveying gasoline, the pipe having opposite inner and outer circumferential surfaces and opposite ends, the pipe further comprising:
a Ni-plated layer with a thickness of 1 to 15 μm provided on all of the inner circumferential surface of the fuel conveying pipe, an anti-rust film layer consisting essentially of a Zn-plated layer or a Zn-based alloy-plated layer provided on the Ni-plated layer at least at one end of the fuel conveying pipe, the anti-rust film layer having a thickness in a range of 0.1 to 8 μm, and when an inner diameter of the fuel conveying pipe is D mm, the anti-rust film layer being provided only up to a position of D to 6D mm from the end of the fuel conveying pipe inward, and at least a portion of the outer circumferential surface of the fuel conveying pipe being covered with a Zn-plated layer or a Zn-based alloy-plated layer.