Why is there diesel oil in PT pump diesel engine oil of Cummins generator set

For the PT fuel system of NT(A)-855 diesel engine of Cummins generator set, the reason and treatment of diesel oil in the oil pan oil is as follows.

1. PT fuel pump. The main function of PT fuel pump is to deliver fuel to the injector at low pressure (0.8-l.2MPa). When the main shaft oil seal at the PT pump coupling fails, fuel will pass through this seal and into the oil pan through the timing gearbox. At this time, the PT pump spindle oil seal must be replaced.

The outlet of PT pump has a solenoid and manual shut-off valve. When the ignition switch is opened, the solenoid shut-off valve is opened and the oil circuit is connected. When the ignition switch is off, the sealing ring of the cut-off valve is closed under the action of the spring plate, and the oil circuit is cut off. When the sealing ring of the cut-off valve fails, the fuel will flow to the injector by itself through the cut-off valve and seep into the oil pan through the combustion chamber. At this time, it is necessary to remove and replace the cut off wide sealing ring.

2. Fuel injector. The injector is used to measure, pressurize (110-120MPa) the fuel output from the PT pump and inject it into the combustion chamber. When the injector injector hole (about 0.2032mm in normal time) is too large or damaged, the fuel will drop into the combustion chamber and leak into the oil pan in the shutdown state. At this time, it is necessary to disassemble and replace the abnormal injector.

If the upper and lower seal rings of the injector fail, the fuel will enter the valve chamber and combustion chamber through the seal rings at any time, and then seep into the oil pan. At this time, it is necessary to remove and replace the failed O-ring seals.

3. The fuel tank of the PT fuel system is in a higher position. In order to prevent the fuel from flowing into the injector by itself through the float tank and PT pump in the shutdown state, a manual cut-off valve is installed at the outlet of the fuel tank. When this stop valve fails, fuel will seep through the combustor and into the oil pan. At this time, it is necessary to repair or replace the globe valve.

4. Float fuel tank. Float valve and conical valve are arranged in the float tank, so that the float tank from the fuel tank to maintain the oil level height and stable oil pressure. When the float valve or cone valve fails, the fuel will leak into the oil pan through the injector through the float tank in the shutdown state. At this time, it is necessary to repair or replace the float valve or cone valve.

5. Oil return manifold. A ONE-WAY CHECK VALVE IS INSTALLED IN THE RETURN MANIFOLD OF THE CumMINS DIESEL GENERATOR PT FUEL SYSTEM TO KEEP THE INJECTOR INLET PRESSURE STABLE AND PREVENT THE FUEL FROM THE FLOAT TANK from FLOWING TO THE INJECTOR. When the one-way check chamber fails, fuel will flow through it to the injector and then seep into the oil pan. At this time, it is necessary to repair or replace the one-way check valve.

Jiangsu Meao Power Technology Co., Ltd. is an important manufacturer of diesel generators. The company mainly manufactures and sells diesel generator sets with power of 3-3000kW, mobile power station of 24-600kW, Marine emergency diesel generator set of 24-800kW, gas generator set, heavy oil generator set and all kinds of imported series, special series (trailer, static speaker, mobile lighthouse, container, etc.) diesel generator At the same time, we are engaged in generator set maintenance and after-sale service of generator set accessories.