Detection of Diesel Generator Overflow Valve and Fuel Pump

The diesel generator relief valve is a hydraulic pressure control valve that mainly plays a role in constant pressure relief, stabilizing, system unloading, and safety protection in hydraulic equipment. If there is gas in the oil coming out of the relief valve, it is necessary to check whether the oil inlet screw of the fuel pump is tightened, otherwise it will cause difficulty in starting or weak acceleration.

If the return oil overflow valve of the diesel generator gets stuck and remains normally open or the opening pressure is too low, the pressure in the plunger chamber of the fuel injection pump will be insufficient, which will lead to insufficient oil in the plunger pump and affect the normal operation of the diesel engine.

On the other hand, if the return oil overflow valve is stuck and closed or the opening pressure is too high, it will cause the fuel temperature in the plunger chamber of the fuel injection pump to rise, and the overheating and expansion of the fuel will cause a decrease in the density of fuel injected into the combustion chamber, resulting in a decrease in the power of the diesel generator and unstable operation failure.

Furthermore, overheated fuel will also lose its proper lubrication and cooling function (only about 30% of the fuel supplied to the plunger chamber of the fuel injection pump is injected into the combustion chamber of the diesel generator, and the rest returns to the fuel tank after taking away the heat from the relevant components of the fuel injection pump), resulting in abnormal damage to precision components such as the plunger. The detection steps are as follows:

1. Install the fuel pressure gauge between the fuel pump outlet and the fuel filter, and ensure that there is no leakage at the connection point. It is best to use transparent plastic pipes for the connection between the pressure gauge and the oil pump, in order to observe the low-pressure oil system with air entering.

2. Start the oil receiver and idle it, record the pressure reading on the fuel pressure gauge. Under normal circumstances, this value should be between 0.131 and 0.303 MPa (Bosch up to pump system parameters), and whether the pressure is too high or too low is abnormal.

3. Observe the fuel flow in the plastic pipe. If there are bubbles, it indicates that there is air entering the oil system from the fuel pump to the fuel tank end, and careful inspection should be carried out. On the contrary, it is normal.

4. Pinch the oil pipe behind the fuel pressure gauge with your hand (be careful to pinch it for a short time), observe the fuel pressure gauge and read the value. This value is the common pressure of the fuel transfer pump. Based on this value, analyze and determine whether there is a problem with the fuel transfer pump and relief valve.

5. After the test is completed, remove the fuel pressure gauge, restore the connection pipeline of the fuel system, and pay attention to the sealing of the joint.

Dingbo Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.