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FIG. 26 – REMOVING THE PRE-ROTATION VANE
ASSEMBLY
9. Manually close the pre-rotation vanes to permit
the linkage to pass through the opening in the cas-
ing. (Rotate Model size 26 vane housing two bolt
holes clockwise to clear linkage.) Install two guide
pins.
10. Slowly ease the PRV housing out until an appro-
priate lifting device can be rigged between the sta-
tionary inlet vanes and a pin or bolt screwed into
the top jack bolt hole. Take up the weight and re-
move the guide pins. Use care to not bump the
rotor journal as the PRV housing is removed. Place
the PRV housing on suitable blocks.
FIG. 27 – PRV HOUSING ASSEMBLY (OPEN AND CLOSED VANES)
YORK INTERNATIONAL
REMOVING PRE-ROTATION VANES
The pre-rotation vane assembly must be removed from
the compressor. The individual vanes seldom require
service. If foreign material has damaged the vanes or
system dirt and corrosion have locked the vanes, vane
disassembly may be required. Vanes are actuated by a
rotating vane driving ring (202) through individual arms
(228). To remove the vanes refer to Figs. 26, 27 and 28.
proceed as follows:
(154)
1. Remove the cap screw (205) securing the washer
(229), vane arm (228), and washer (204), to the
pre-rotation vane.
2. Remove the arm, two washers, and vane (203)
LD07342
by pulling vane toward the inside of the vane
housing.
REPLACING PRE-ROTATION VANES
Individual vanes have an airfoil section and overlap
slightly when in the closed position. Ensure the over-
lap is such that when facing the PRV housing inlet,
counter clockwise rotation of the control shaft (206)
will open the vanes, and clockwise will close them.
All vanes must move in unison and the heavy end of
the airfoil must point into the gas stream. Check the
ballstud and special fulcrum joints for wear and replace
if required.
FORM 220.11-NM2 (602)
4
LD07343
53
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