Rotating 65fp Fuel Servo

M

Thread Starter

mohanad

dear gents

I want to know how to move the 65Fp while the unit is offline. I had a problem that the liquid fuel valve opened about 2% while the unit is running on gas fuel, is there any reason causes this opening? and
how can I move the 65fp to check that it's fully closed and not opened?

the unit is Fr6001b
controller is MK Vie
 
mohanad,

When did this problem start?

After the liquid fuel pump servo-valve was changed?

I'm presuming there is LVDT feedback, so did the problem start after someone "calibrated" the liquid fuel pump swash plate LVDT(s) or replaced an LVDT on the liquid fuel pump swash plate?

This is an older machine retrofitted/upgraded with a Mark VIe if it has a rotating high-pressure axial piston liquid fuel pump.

If the unit is running on gas fuel the liquid fuel stop valve should be closed, so there should be no liquid fuel flowing to the unit--<b>plus</b> the electric clutch between the liquid fuel pump and the accessory gear should be de-energized (or if an electric motor is being used to drive the pump it should not be running).

Leaking liquid fuel check valves have been known to allow pressure to flow into the liquid fuel flow divider and it could cause the swash plate to move.

To move the swash plate you're going to have to use the Manual Position feature of the 96FP LVDT(s) Auto Calibrate. You'll need to establish hydraulic pressure and then you can move the swash plate with the manual feature of Auto Calibrate for the fuel pump servo LVDTs. It may be necessary to energize the liquid fuel trip solenoid; without being able to see the Liquid Fuel and Trip/Control Oil P&IDs I can't recall.

If I recall correctly, there is no spring which returns the liquid fuel pump swash plate back to zero flow. (The angle of the swash plate controls the flow through the positive displacement axial piston liquid fuel pump.) So, if the unit is running on gas fuel and the swash plate moved, either it's because of vibration or something like one or two leaking liquid fuel check valves. What I can't remember is how trip oil/control oil acts in conjunction with hydraulic oil to keep the liquid fuel swash plate from moving from the zero flow position.

Please write back to let us know how you fare!
 
Top