6.2 Annual Inspection. Once a year or as required, depending on the severity
of service, clean and inspect the compressor for the following conditions:
(a) Corrosion or erosion of parts
(b) Proper clearances
(c) Correct alignment
(d) Worn or broken timing gears
(e) Timing gear setting
(f) Operation and setting of safety valves
(g) Wear of shafts at seals
7.1 Lubrication. Establish a definite lubrication schedule for the
compressor, and establish specific responsibilities for carrying out periodic
lubrication. Frequency of lubrication and type of lubricant should be as
recommended by the manufacturer.
rotative position and hold impeller clearances. They must be securely locked
to their shafts in proper position. Gears or impellers that have been removed
for repair must be returned to their original positions. When installing new
or repaired parts, carefully follow the manufacturers' instructions for
setting clearances. Clearances must be set accurately or damage to the
machine may result from impeller rubbing.
7.3 Seals. Rotary twin-lobe compressors are normally fitted with mechanical
seals. Seals should be kept free of dirt, dust, and foreign matter to ensure
long life. Sealing faces are lapped together during manufacture and the
entire assembly must be replaced when defective seals are found. Use extreme
care when installing seals to prevent marring of the sealing faces. Be sure
that the lapped sealing faces are free of scratches, dust, or finger marks
before installation. Carefully follow the manufacturers' instructions when
replacing mechanical seals.
7.4 Bearings. Rotary twin-lobe compressors are normally fitted with
antifriction ball or roller bearings. Worn or defective bearings should be
replaced. Wear to bearings may allow the impeller shaft to shift position
until a cylinder rub develops or the impellers begin rubbing. Carefully
follow the manufacturers' instructions when replacing bearings.