Chapter 5 Maintenance and Inspection
UD-series Screw Compressor
5.4 Disassembly and Inspection
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5.4.8 Balance Piston Cover
The balance piston cover (part number 22) can be easily reassembled by removing it together
with the unloader cylinder as described in Section 5.4.5 “Unloader piston and cylinder”.
Pay
attention to the following points when removing only the balance piston cover after removing the
unloader cylinder.
Disassembly
a) Loosen all the hexagon socket head cap screws (part number 24) by 3 to 4 turns, screw the
eyebolts into the screw holes of the balance piston cover, and remove the cover gasket (part
number 23) which is in close contact.
b) In this condition, oil accumulated in the balance piston and side bearing section of the suction
cover is discharged.
Once the oil has been drained, remove all other bolts leaving one of the
upper bolts.
While pressing the cover by hand and remove the remaining bolts from the
suction cover without damaging the gasket.
Removing the Balance Piston Cover