IMI-CPP - page 10

BULLETIN IMI-CPP
JUNE 2011
PAGE10
7. Install an 'O' ring in the 'O' ring groove in thepiston
8. Install an 'O' ring in the 'O' ring groove in thepiston housing end plate.
9. Apply a thin coat of white lithium grease to a cleaned piston housing insidediameter;
a cleaned piston 'O' ring; cleaned piston guide rods; and a cleaned end plate 'O'
ring.
10. Place the six springsonto thepiston guide rods.
11. Slide thepiston assembly into thepiston housing and align thebalancing
matchmarks.
NOTE: Align the 'keyway' on theendof thepistonhubwith the 'key' on
theendof the straight boreadapter bushing.
Thepiston guide rodsmust pass through thepiston housing guide rod
bushings.
12. Place the flat washer and 'O' ring onto thehex socket head cap screw. Apply Loctite
#271 to thehex socket head cap screw threads.
13. Insert thehex socket head cap screw through the center hole in thepiston. Thread
thehex socket head cap screw into the tapped hole in theend of themotor shaft.
Check that thepiston assembly isproperly seated. Tighten and torque thehex socket
head cap screw to sixty-five foot-pounds.
14. Install thepiston housing end plate to thepiston housing. Secure theend platewith
theeight hex socket head cap screws. Tightenand torque to five foot-pounds.
15. Apply Loctite#271 to the rotating union threads. Install the rotating union to the
piston housing end plate. Tighten and torque the rotating union to seven foot-pounds.
16. Check theblade settings:
A. With the supply air disconnected from theactuator, check that the
actuator ispositioned at itsminimum position.
B. Calibrate thepilot positioner per the instructions inSection
C.
INSTALLATIONANDSTART-UP, CalibrationofPilot Positioner
.
C. Activate theactuator. Check that themaximum actuator travel results in the
original maximum blade setting and that theminimum actuator travel results
in theoriginalminimum blade setting.
D. If necessary, adjust theblade settings:
a. Loosen the crankarm set screwsand clamp screws to allow
blade rotation inside the crankarms.
NOTE:
Crankarm
SET
screws should
NOT
be retightened until last.
* b. Oneat a time, rotate thebladesuntil the indexmarksare set to
theoriginal maximum blade settings, PLUSone-half a setting.
Repeat
'C'
above.
E. Tighten the crankarm clamp screwsevenlyand torque to the value
shown in
CHART 3
. Tighten the crankarm set screwsand torque to the
value shown in
CHART 3
.
CHART 3: BLADECRANKARMTIGHTENINGTORQUES
FAN
MODEL
CLAMPSCREW
TORQUE
[FT-LB]
SETSCREW
TORQUE
[FT-LB]
'B' HUB
10.0
10.0
'C' HUB
15.0
15.0
1,2,3,4,5,6,7,8,9 11
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