Cummins Diesel Generator PT Fuel System
by Starlight Generator dieselgeneratortechIn order to ensure the normal performance
of the diesel engine technology, the fuel pump must be commissioned on the
dedicated test bench according to the PT fuel pump calibration data. At
present, the flow meter method is often used, and the specific test steps are
as follows.
1. Install the fuel pump on the
test bench. After the fuel pump is connected to the drive plate, fill the pump
housing and the oil inlet of the gear pump with the clean test oil from the
plug hole at the top of the fuel pump. Connect the oil inlet rubber hose and
the cooling drain valve hose; check whether the regulator is stable to ensure
the gear pump works stably; adjust the pointer of each measuring instrument to
zero.
2. The idle speed small hole
valve, the throttle valve and the leakage valve on the test bench are closed,
and the vacuum regulating valve, the oil shutoff valve and the flow regulating
valve are fully opened. The throttle valve of the fuel pump is in the fully
open position, and the two-arm lever of the MVS governor is in contact with the
high speed limit screw. The motor is started to allow the fuel pump to be
commissioned at 500 rpm. If the fuel pump does not absorb oil, check whether
the valve in the oil inlet line is open, whether there is air leakage, or the
direction of rotation of the fuel pump is reversed; test operation for more
than 5 minutes, let the air discharge from the oil, the oil temperature rises
to 32-38 ° C.
3. Check the tightness of the
fuel pump. At 500 rpm, open the flow adjustment valve, close the vacuum adjustment
valve, the vacuum gauge reading should be 40KPA, apply a small amount of light
grease to the vent hole of the fuel pump front cover spindle seal , if not
inhaled, it means good sealing; check the O-ring of the throttle valve, the
chronograph seal ring hole, the MVS governor double-arm lever shaft and the
adjusting screw, the gasket between the gear pump and the housing, etc. Sex.
Observing the air bubbles in the flow meter just indicates that some of the air
has entered the fuel pump.
4. Adjust the vacuum. The flow
regulating valve on the test bench is fully opened, the fuel pump is operated
at the rated speed of the diesel engine, and the vacuum regulating valve is
adjusted to make the vacuum gauge read 27KPA.
5. Adjust the flow meter. The fuel
pump is operated at the rated speed of the diesel engine, and the flow
regulating valve is adjusted to adjust the float of the flow meter to a
prescribed value.
6. Adjust the speed at which the
governor is disconnected. The throttle valve is fully open, and the fuel pump
speed is increased until the fuel pressure begins to decrease. Check whether
the fuel pump opening point speed is within the specified value. If it is lower
than the specified value, a gasket can be added between the adjusting spring
and the snap ring; otherwise, the gasket should be taken out. When equipped
with the MVS governor, just use the high speed limit screw adjustment.
7. Check the fuel pressure point.
Increase the fuel pump speed. When the fuel pressure drops to 276KPA, check if
the fuel pump speed is within the specified range. The fuel pump speed will
continue to rise and its fuel pressure should be reduced to zero. Otherwise,
the fuel short circuit in the fuel pump is indicated.
8. Commissioning of the fuel
outlet pressure at the rated speed and maximum torque point speed. Starting
from zero fuel pressure, reduce the fuel pump speed to the rated speed and
check if the fuel outlet pressure meets the specified value. When the MVS governor
is not installed, use the increase or decrease of the gasket to adjust. When
the MVS governor is installed, adjust the screw with the rotary throttle valve.
When the fuel pump speed drops to the maximum torque point speed, check if the
fuel outlet pressure meets the specified value. It can be adjusted by changing
the amount of boosting plunger, that is, increasing the gasket of the low-speed
torque correction spring to increase the fuel pressure, and vice versa.
9. The fly hammer assists in the
inspection of the pressure. Run the fuel pump at 800 rpm to check that the fuel
outlet pressure meets the specified value. The adjustment method is also to use
a gasket that increases or decreases the low speed torque correction spring. It
should be noted that the adjustment of the above items 4-8 is required after
the thickness of the gasket is changed.
10. Adjustment of idle speed and
fuel outlet pressure. The throttle valve, the leakage valve and the flow
regulating valve on the PT pump test bench open the idle small orifice valve to
make the fuel pump throttle shaft idle at the idle position, so that the fuel
pump runs at an idle speed and check whether the fuel outlet pressure meets the
specified value. It can be adjusted with the idle adjustment screw.
11. Check the amount of leakage
of the throttle valve. The flow regulating valve and the idle small orifice
valve on the PT fuel pump test bench are closed, and the throttle valve and the
leakage valve are opened. When the throttle valve is in the idle position, the
fuel flows into the measuring cup, and the leakage amount should meet the
specified value. The PTG governor uses a front limit screw to tighten the
throttle to adjust the amount of leakage, while the MVS governor is adjusted by
increasing or decreasing the leakage adjustment pad on the outside of the idle
spring seat.
After repeating the inspection
and adjustment of the above items 3-11, seal the throttle valve limit screw of
the PT fuel pump, the high speed limit screw of the MVS governor, and the
chronograph.
Note: We can provide 24KW to 2400KW Cummins Diesel Generator with Stamford/Leroy-Somer/Marathon/Siemens/Starlight alternator.
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Created on Dec 14th 2018 00:11. Viewed 531 times.