(b)  
Loosen the bottom index screw, but do not remove it.

 (c)  
Install the alignment tool (Fig. 402):

 (d)  
Put the alignment tool in its position with the two guide pins in the holes left by the two index screws that you removed (the scale should be on the top of the tool).

 (e)  
Make sure the spline on the tool engages with the spline on the shaft.

 S 824-131
 (2)  Do these steps to align the adapter shaft (Procedure 1, optional to Procedure 2):
 NOTE: This procedure finds the point where the internal valve
____ butterfly engages the valve seal. The torque required to turn the shaft increases as the butterfly engages the seal, then decreases again as the butterfly leaves the other side of the seal. Once the edge of the seal is found, the valve shaft will then be turned to center the butterfly on the seal.
 (a)  
Put the tool handle in the extreme counterclockwise position.

 (b)  
Turn the handle slowly in the clockwise direction at a constant rate while you note the changes in the torque necessary to turn the handle.

 (c)  
Do the previous steps as many times as necessary to find the point in the rotation where the torque necessary to turn the handle increases significantly.

 (d)  
If you cannot find the position in the rotation where the torque increases significantly , then use Procedure 2 below.

 (e)  
Put the shaft in the extreme counterclockwise position again.

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757
MAINTENANCE MANUAL

 (f)  
Slowly and smoothly turn the handle of the tool clockwise until a distinct increase in torque is found and immediately stop turning the handle.

 (g)  
Read the scale on the tool.

 NOTE: This is the point where the valve butterfly starts
____
 to engage the edge of the seal.

 (h)  Turn the handle 13 degrees more in the clockwise direction (the scale on the tool is calibrated in degrees).
 NOTE: The valve butterfly is now centered on the valve seal.
____
 NOTE: If you turn the handle past the target value, do not
____ turn the handle back in the counterclockwise direction again. You must start the procedure again with the handle in the extreme counterclockwise position.
 S 824-132
 (3)  Do these steps to align the adapter shaft (Procedure 2, optional to procedure 1):
 NOTE: A torque meter is necessary to do this procedure.
　
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