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Liquid fuel bypass valve calibration.
The liquid fuel bypass valve on one of our machines has been identified as over travelling and the recommendation from the Controls TA on site was to adjust this out in the calibration. ACALIB.DAT has been updated so that the Negative saturation current is now greater than 100%. Now when the valve is stroked the correct stroke lenght is achieved for 0-100%.
My concern with this is that 100% is the closed position and now by reducing the stoke in this manner there is a possiblity that the full fuel flow may not be acheived. If the adjustment was made at the oposite end at the fully open position, it would have little or no effect on operation.
The TA has so far rejected any concerns raised and has stated that the LFBV shouldn't close fully to protect the pump. If the this is the case what is the purpose of the relief valve (VR4). I can't help but think i am being fobbed off.
I have data the indicates this valve was running at 99% for base load operation.
any comments regarding this would be appreciated.
Thanks
The liquid fuel bypass valve on one of our machines has been identified as over travelling and the recommendation from the Controls TA on site was to adjust this out in the calibration. ACALIB.DAT has been updated so that the Negative saturation current is now greater than 100%. Now when the valve is stroked the correct stroke lenght is achieved for 0-100%.
My concern with this is that 100% is the closed position and now by reducing the stoke in this manner there is a possiblity that the full fuel flow may not be acheived. If the adjustment was made at the oposite end at the fully open position, it would have little or no effect on operation.
The TA has so far rejected any concerns raised and has stated that the LFBV shouldn't close fully to protect the pump. If the this is the case what is the purpose of the relief valve (VR4). I can't help but think i am being fobbed off.
I have data the indicates this valve was running at 99% for base load operation.
any comments regarding this would be appreciated.
Thanks