PLUG，PIPE

A pipe is a rigid tube that carries a fluid or gas between parts of a commercial vehicle's systems.

It routes coolant, fuel, oil, air, or exhaust along a fixed path, holding pressure and resisting heat so the fluid reaches its destination without leaking.

Pipes appear in the cooling, fuel, air/brake, lubrication, and exhaust systems. The right pipe matches the system, the routing, and the connections at each end.