070.610-IOM (JUL 21)
Page 41
RWF II Rotary Screw Compressor Units
Maintenance
Vibration analysis
Periodic vibration analysis can be useful in detecting
bearing wear and other mechanical failures. If vibration
analysis is used as a part of your preventive main tenance
program, take the following guidelines into consideration.
1.
Always take
vibration readings from exactly the same
places and at exactly the same percentage of load.
2.
Use vibration readings taken from the new unit at
start-up as the base line reference.
3.
Evaluate vibration readings carefully as the instru ment
range and function used can vary. Findings can be eas
-
ily misinterpreted.
4.
Vibration readings can be influenced by other equip-
ment operating in the vicinity or connected to the
same piping as the unit.
Figure 45: Multivalve Arr. - 496, 676, 856 and 1080
the head may have increased through wear to the point
where the pump is losing capacity or pressure. Resetting
end clear ance will normally improve pump performance.
See Technical Service Manual on particular model series
for procedure on adjusting end clear ance for the pump
involved.
Maintenance program
To obtain maximum compressor unit perform ance and
ensure reliable operation, follow a regular main tenance
program.
Check the compressor unit daily for leaks, abnormal vibra-
tion,
noise, and proper operation. A log should also be
maintained. Initial oil analysis and vibration analysis should
be done at start-up and continued per the maintenance
schedule.
Vibration analysis is recommended every 6 months to
ensure that the internal components of the screw com-
pressor are in compliance with expected vibration levels,
based on the initial, full spectrum baseline performed at
start-up. If the Frick PhD on-board vibration monitoring
system is utilized, the 6 month vibration analysis is not re-
quired. Frick PhD provides continuous vibration monitoring
that fulfills the maintenance requirement. If the Frick PhD
has an alarm or shut down event, a full spectrum vibration
analysis would then be required to specifically identify the
cause of the alarm or shut down.
In addition, a Frick compressor package without PhD
monitoring already in operation can be retrofitted with the
Frick PhD on-board vibration monitoring system to fulfill
the vibration maintenance recommendation. However, it is
also necessary to establish a current baseline vibration with
a full spectrum analysis in order for the PhD retrofit to be
compliant.
Table 13: RWF II bolt sizes and torque values
RWF II
model
Compressor
model
Disch. flange to separator flange
Compressor suction flange
Strainer trap Multi-valve inlet
Bolt size (mm) Torque* (ft-lb) Bolt size (mm) Torque* (ft-lb) Torque* (ft-lb) Torque* (ft-lb)
100/119 SS SGC 1913
M20 X 2.5
180
M20 X 2.5
180
180
—
134/159 SS SGC 1918
M20 X 2.5
180
M20 X 2.5
180
180
—
177/209 SS SGC 2313
M20 X 2.5
180
M20 X 2.5
180
180
—
222/264 SS SGC 2317
M20 X 2.5
180
M22 X 2.5
280
280
—
270
SGC 2321
M20 X 2.5
180
M22 X 2.5
280
280
—
316/375 SS SGC 2813
M22 X 2.5
280
M22 X 2.5
280
280
—
399/472 SS SGC 2817
M22 X 2.5
280
M24 X 3.0
300
300
—
480
SGC 2821
M22 X 2.5
280
M24 X 3.0
300
300
—
546
SGC 2824
M22 X 2.5
280
M24 X 3.0
300
300
—
496
SGCB/H 3511 M24 X 3.0
300
M30 X 3.5
350
250
250
676
SGCB/H 3515 M24 X 3.0
300
M30 X 3.5
350
250
250
856
SGCB/H 3519
SGXB/H 3519
M24 X 3.0
300
M30 X 3.5
350
250
250
1080
SGXB 3524
M24 X 3.0
300
M30 X 3.5
350
250
250
* Based on:
Gaskets-Garlock
®
Blue-Gard
®
3300; Bolts-class 8.8 or stronger hex head bolts, lightly oiled and clean
