: JGW, JGR
AND
JGJ
S
ECTION
5 - M
AINTENANCE
PAGE 5 - 18
Piston and Rod - Removal
1.
Remove the crosshead guide side covers and the cylinder head. The cylinder
head is to be loosened first to the Caution! instructions above.
2.
Move the crosshead to its inner dead center position. Back off, but do not
remove, the crosshead nut set screws. Loosen the crosshead nut with the spe-
cial slugging wrench, (see Figure 7-1: on page 7-3). Use the open-end wrench
for hex nuts and the peg wrench for round nuts.
3.
Remove the cylinder head. In the case of tandem cylinders where the outboard
cylinder bore is smaller than the inboard bore, it is necessary to remove the out-
board cylinder. Support such cylinders during removal and installation, as to not
put excessive weight on the piston and rod assembly which might cause bend-
ing.
4.
Use the Piston Nut Spanner and Ratchet Extension Support to screw the piston
and rod assembly out of the crosshead. Refer to Figure 5-11: on page 5-19. The
two dowels on the Piston Nut Spanner fit the holes in the piston nut. Turn the
crosshead nut off the piston rod.
5.
As the piston leaves the cylinder, be careful in handling the piston rings. Despite
their toughness in service, rings are fragile with regard to removal. Always han-
dle them with clean tools and hands protecting the rings from nicks, marring,
and bending. Move the piston out of the cylinder until a fraction of the first ring
clears the cylinder. Encircle the ring by hand (use a band for larger sizes) until it
is clear and remove it. Use this same procedure to remove the succeeding rings
and wear band.
6.
Slide the piston rod out of the head end. The threaded crosshead end of the rod
is 1/8 inches (3 mm) smaller in diameter than the inside diameter of the packing.
Using extreme care, slowly slide the piston rod through the packing to avoid
damaging the rod threads or the packing rings.
CAUTION
TO PREVENT PERSONAL INJURY, ENSURE THAT COMPRESSOR
CRANKSHAFT CANNOT BE TURNED BY THE DRIVER OR COMPRES-
SOR CYLINDER GAS PRESSURE DURING MAINTENANCE: -- ON
ENGINE-DRIVEN COMPRESSORS, REMOVE THE CENTER COUPLING
OR LOCK THE FLYWHEEL. -- ON ELECTRIC MOTOR-DRIVEN COM-
PRESSORS, IF IT IS INCONVIENIENT TO DETACH THE DRIVER FROM
THE COMPRESSOR, THE DRIVER SWITCH GEAR MUST BE LOCKED
OUT DURING MAINTENANCE.
BEFORE PERFORMING ANY MAINTENANCE, COMPLETELY VENT
SYSTEM. BEFORE REMOVING A CYLINDER HEAD, BACK OFF ALL
CAPSCREWS 1/8" (3 mm). MAKE SURE THE HEAD IS LOOSE AND THE
CYLINDER IS COMPLETELY VENTED.
!
Summary of Contents for JGJ Series
Page 30: ...FOR MODELS JGW JGR AND JGJ SECTION 1 DESIGN SPECIFICATIONS DATA PAGE 1 24 1 01 NOTES ...
Page 34: ...FOR MODELS JGW JGR AND JGJ SECTION 2 INSTALLATION PAGE 2 4 1 01 NOTES ...
Page 44: ...FOR MODELS JGW JGR AND JGJ SECTION 3 START UP PAGE 3 10 1 01 NOTES ...
Page 114: ...FOR MODELS JGW JGR AND JGJ SECTION 5 MAINTENANCE PAGE 5 42 1 01 NOTES ...
Page 120: ...FOR MODELS JGW JGR AND JGJ SECTION 6 TECHNICAL ASSISTANCE PAGE 6 6 1 01 NOTES ...
Page 130: ...FOR MODELS JGW JGR AND JGJ SECTION 7 APPENDICES PAGE 7 10 1 01 NOTES ...
Page 135: ......
Page 136: ......
Page 137: ......
Page 138: ......
Page 139: ......
Page 140: ......
Page 141: ......