3-1
SECTION 3
COMPRESSOR MAINTENANCE
3.1 INTRODUCTION
Prior to disassembly of the compressor, oil must first
be drained from the crankcase. Place the compressor in a
position where it will be convenient to drain the oil.
Remove the oil fill plug to vent the crankcase. Loosen the
drain plug and allow the oil to drain out slowly.
If dismantled parts are to be left overnight or longer,
dip them in clean compressor oil (to prevent rusting) and
store in protected area.
Refer to Table 3-1 for torque values for tightening
bolts.
3.2 INSPECTION AND PREPARATION FOR
REASSEMBLY
a.
Clean all parts with an approved solvent. Use a
stiff bristle brush to remove dirt from grooves and
crevices.
b.
Inspect all parts for wear and overall condition.
Replace any defective or excessively worn parts.
c.
Inspect suction and discharge valve seats (on
valve plate).
d.
If unloaders are installed, inspect operation of
unloader.
e.
After cleaning, ensure all moving parts are
coated with compressor oil before reassembly.
f.
Use only new gaskets during reassembly. Ensure
all gaskets (includes cylinder head, valve plate, and
unloader or bypass plug gaskets) are installed dry.
3.3
CYLINDER HEAD AND VALVE PLATE
a. Disassembly
WARNING
Do not unscrew capscrews all the way before
breaking seal. Entrapped pressure could result
in injury.
1.
Loosen cylinder head capscrews. If the head is
stuck, tap it lightly with a wooden or lead mallet to free it.
Be careful not to drop the head or damage the gasket
sealing surface. Remove cylinder head capscrews and
gasket. (See Figure 3-1)
2.
Remove the discharge valve capscrews, lock
washers, stops, and valves.
3.
Free the valve plates from the cylinder deck by
using the discharge valve capscrews, without washers, as
jackscrews through the outermost tapped holes in the
valve plate after the valve stops and valves have been
removed. Remove the valve plate gasket.
4.
Discard valves and gaskets. Use only new valves
and gaskets when assembling cylinder head and valve
plate assemblies.
b. Reassembly
Some 05G compressors for refrigeration use only
may have “canted” valve plates. The “canted valve”
design allows a reduction in the distance between the
discharge valve and the top of the piston. When piston is
at TDC the volume of the compression chamber is
smaller, contributing to increased compressor efficiency.
1.
Install only new valves and gaskets, and do not
interchange valves.
7
6
5 4
1
11 10
9
3
8
CANTED
2
12
8
FLAT
4, 5, 6, 7
1. Capscrew
2. Cylinder Head
3. Cylinder Head Gasket
4. Capscrew
5. Lockwasher
6. Discharge Valve Stop
7. Discharge Valve
8. Valve Plate
9. Valve Plate Gasket
10. Suction Valve
11. Position Spring
12. Dowel Pin
Figure 3-1. Cylinder Head & Valve Plate
