Heavy Duty Balanced Opposed Compressors - Ariel Corporation
Heavy Duty Balanced Opposed Compressors - Ariel Corporation
Heavy Duty Balanced Opposed Compressors - Ariel Corporation
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FOR MODELS: JGZ AND JGU SECTION 5 - MAINTENANCE<br />
crosshead guide. A 0.0015 inches (0.04 mm) feeler stock should not be able to be inserted<br />
more than 1/2 inches (13 mm) at all four corners of the crosshead.<br />
Before rotating the crankshaft, operate the pre-lube pump to lubricate the bearings.<br />
Position the dial indicator 1 stem against the piston rod, close to the packing case. Set the<br />
indicator to zero with the piston at the crank end. Readings are to be taken in both the vertical<br />
and horizontal directions. When measuring vertical rod movement, upward movement<br />
will be recorded as positive, downward movement will be recorded as negative. When measuring<br />
horizontal rod movement, rod movement toward the auxiliary end of the frame, will be<br />
recorded as a positive reading, movement toward the drive end of the frame will be recorded<br />
as a negative reading. Copy Table 5-2 to record readings. Manually rotate the crankshaft<br />
and record readings at mid-stroke and with piston at the head end.<br />
TABLE 5-2 PISTON ROD RUN OUT<br />
THROW NUMBER: 1 2 3 4 5 6<br />
VERTICAL<br />
HORIZONTAL<br />
Compare readings to Table 5-3.<br />
Piston @ CE<br />
Mid-Stroke<br />
Piston @ HE<br />
0 0 0 0 0 0<br />
Piston @ CE<br />
Mid-Stroke<br />
Piston @ HE<br />
0 0 0 0 0 0<br />
TABLE 5-3 MAXIMUM ACCEPTABLE PISTON ROD RUN OUT READINGS<br />
DIRECTION INCHES (mm)<br />
Vertical 0.0025 (0.064)<br />
Horizontal 0.0010 (0.025)<br />
If a vertical reading is greater than the maximum acceptable reading, the following procedure<br />
is to be used to determine acceptability: With the piston at the head end, use feeler<br />
gages to determine clearance at the top of the piston. On wear band or rider ring pistons,<br />
this clearance is over the rings or wear band. Feeler top clearance is to be divided by two (/<br />
2) and then subtract (-) 0.005 inches (0.13 mm). Place a feeler of this calculated thickness<br />
under the bottom of the piston. Place the feeler under the wear band or rider ring on wear<br />
band or rider ring pistons. This feeler is to be long enough to stay under the piston as the<br />
piston is moved throughout its stroke. Re-measure vertical run out and compare to accept-<br />
1. Use a 0.0001 inches (0.001 mm) increment calibrated dial indicator.<br />
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