Introduction of Oil&Water Pipe

The Function of Oil&Water Pipe:
It is to allow excess oil to flow back to the fuel tank to reduce oil consumption. Not all cars have a return hose.
The oil return line filter is installed at the oil return line of the hydraulic system. It is used to filter the worn metal powder and rubber impurities of the components in the oil, so that the oil flowing back to the oil tank is kept clean.
The filter element of the filter uses chemical fiber filter material, which has the advantages of high filtering accuracy, large oil permeability, small original pressure loss, and large dirt holding capacity, and is equipped with a differential pressure transmitter and a bypass valve.

When the filter element is blocked until the pressure difference between the inlet and outlet is 0.35MPa, a switching signal is issued. At this time, the filter element should be cleaned or replaced. Protection System. The filter is widely used in heavy machinery, mining machinery, metallurgical machinery and other hydraulic systems.
Now most cars have oil return pipes. After the fuel pump supplies fuel to the engine, a certain pressure is formed. Except for the normal supply of fuel nozzle injection, the remaining fuel is returned to the fuel tank through the oil return line, and of course there is excess gasoline collected by the carbon canister The steam also returns to the fuel tank through the fuel return pipe. The fuel return pipe can return excess oil to the fuel tank, which can relieve the pressure of gasoline and reduce fuel consumption.
Diesel fuel supply systems are generally provided with three return lines, and some diesel fuel supply systems are provided with only two return lines, and there is no return line from the fuel filter to the fuel tank.

Return line on the fuel filter
When the fuel pressure provided by the fuel pump exceeds 100 ~ 150 kPa, the overflow valve in the return line on the fuel filter opens, and the excess fuel flows back to the fuel tank through the return line.

Oil return line on fuel injection pump
Since the fuel delivery volume of the fuel pump is two to three times the maximum fuel supply capacity of the fuel injection pump under calibration conditions, excess fuel flows back to the fuel tank through the fuel return pipe.

Return line on the injector
During the operation of the injector, a very small amount of fuel will leak from the needle valve and the mating surface of the needle valve body, which can play a role of lubrication, so as to avoid excessive accumulation and the needle valve back pressure being too high and the operation failure. This part of the fuel is introduced into the fuel filter or fuel tank through the hollow bolt and the return pipe.

Judging failure:
In automobile engines, the oil return pipe is an inconspicuous part, but it plays an important role in ensuring the normal operation of the engine. The arrangement of the oil return pipe in the car is relatively special. If the oil return pipe leaks or is blocked, it will cause various unexpected failures. The oil return pipe is a “window” for troubleshooting the engine. Through the oil return pipe, you can skillfully check and judge many engine failures. The basic inspection method is as follows: Open the oil return pipe to check and quickly determine the working condition of the fuel system. Whether the fuel pressure of the fuel system of the injection engine is normal. In the absence of a fuel pressure gauge or a fuel pressure gauge having difficulty accessing the fuel line, it can be indirectly judged by observing the oil return situation of the oil return pipe. The specific method is (take Mazda Protégé car as an example): disconnect the oil return pipe, then start the engine and observe the oil return. If the oil return is urgent, the fuel pressure is basically normal; if the oil return is weak or no oil return, it indicates that the fuel pressure is insufficient, and you need to check and repair electric fuel pumps, fuel pressure regulators and other parts. The fuel flowing out of the oil pipe is introduced into the container to prevent environmental pollution and fire).

Post time: Apr-16-2021