Setting the CounterBalance Valves for a Centrifugal Extractor or a Washer Extractor.

On the Centrifugal Extractor, the machine tilts up by two hydraulic cylinders to discharge a batch of linen, and then tilts down by the same hydraulic cylinders to the load position to receive another batch of linen.   

It is important that both hydraulic cylinders stroke up and down at the same rate of travel.   If one side strokes at a faster rate than the other side the frame will twist and a fatigue failure will result.  

Attached is a picture of both a centrifugal extractor and a washer extractor showing the counterbalance valve cartridges inserted into a mounting block.   The block is located at the base of the hydraulic cylinder.  Note there are two cylinders, thus two sets of counterbalance valves.    In the picture, one counterbalance valve is in a green box, and the second is in a red box.  The bottom counterbalance valve  (shown in the red box) controls the hydraulic cylinder in the up direction.   The top counterbalance valve (shown in the green box) controls the hydraulic cylinder in the down direction.   Knowing this helps decide which valve to adjust.  

Adjustments are started by turning both counterbalance valves fully clockwise.   We turn the top counterbalance valve out (counter-clockwise CCW) 1 full turn.    We turn the bottom counterbalance valve out (counter-clockwise CCW) 3/4 of a turn.  

---Then, take manual control of the machine and tilt up to the cylinders full travel.   If one side is stroking slower than the other side, we adjust that side.   We turn the counterbalance valve clockwise 1/16 of a turn.   Note this would be for the bottom counterbalance valve in the block (red box in the picture).  
---Tilt the machine down using manual control.   If one side is stroking slower than the other side, we adjust the slow side.   We turn the counterbalance valve clockwise 1/16 of a turn.   Note this would be the top counterbalance valve in the block (green box in the picture).   

Continue tilting the machine up and down, adjusting as necessary until both cylinders stroke at the same rate of travel.

NOTE:  AFTER YOU ARE COMPLETED WITH ADJUSTMENTS, TILT THE MACHINE HALF WAY AND STOP.   THE MACHINE SHOULD HOLD ITS POSITION AND NOT DRIFT DOWN.   IF IT DRIFTS DOWN THE COUNTERBALANCE VALVES ARE ADJUSTED TOO FAR COUNTER-CLOCKWISE.   THEY MUST BE TURNED IN CLOCKWISE.