070.550-IOM (JUN 2016)
Page 18
NGC GAS ROTARY SCREW COMPRESSOR
MAINTENANCE
RECOMMENDED MAINTENANCE SCHEDULE
REQUIRED
MAINTENANCE
(To fulfill warranty conditions)
HOURS OPERATION (MAXIMUM)
200
750
5,000
8,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
50,000
55,000
60,000
65,000
70,000
75,000
80,000
85,000
90,000
95,000
CHANGE OIL
As Directed By Oil Analysis
OIL ANALYSIS
One to three months, depending on gas composition and recommendation of system
provider or Frick Oil Analysis Report.
REPLACE OIL FILTER(S)*
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Maximum interval between filter(s) replacement = 2,250 hours.
VIBRATION ANALYSIS**
Maximum every 6 months; more frequently if levels increase.
REPLACE SEAL
When leak rate exceeds 7 - 8 drops per minute.
MALE ROTOR END PLAY
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* REPLACE FILTER(S)
Compressor oil filter(s) should be replaced at
200 hours
and again within the first
750
hours
of new compressor operation. However, if the compressor oil filter differential
reaches
10 psid
before either of these scheduled maintenance points - replace the oil
filter(s).
For Natural Gas Applications, compressor oil filter(s) replacement is recommended
every
2,250 hours
of compressor operation, with compressor oil filter differential
not
exceeding 10 psid.
Systems that contain comtaminants may require more frequent
compressor oil filter(s) replacement, as compressor oil filter differential should not
exceed 10 psid.
** VIBRATION ANALYSIS
Periodic vibration spectra should be recorded giving velocity, acceleration, and spike
energy or acceleration enveloping data against frequency every 6 months, or more
frequently if levels are increasing.
If an FFT Spectrum Analyzer is not available, vibration trending, using an overall
vibration meter may be substituted. The overall vibration meter should be available to
read Velocity (zero-peak, in/sec), and Acceleration (g’s). The overall vibration meter
Velocity range should be 0 - 1000 Hz. The Acceleration range should be 0 - 10,000 Hz.
If vibration trending is to be used to monitor changes in the condition of the
compressor, a baseline must be established within the first 750 hours of operation and
rechecked every 3-6 months thereafter.
Overall vibration readings should be taken using Acceleration and Velocity for CMIA,
CFIA, CIV, and COV. The overall readings should be recorded and kept on file.
Action should be taken if overall vibration reading increases to 1.5 times baseline velocity
readings, or to 2.0 times baseline acceleration readings, taken at 100% Slide Valve position.
Use of Frick PhD on-board vibration analysis is an acceptable substitute for periodic
readings.
RECOMMENDED MAINTENANCE PROGRAM
In order to obtain maximum compressor performance and
ensure reliable operation, a regular maintenance program
should be followed.
The compressor unit should be checked regularly for leaks,
abnormal vibration, noise, and proper operation. A log
should also be maintained. Oil analysis should be performed
on a regular basis. It is a valuable tool that can identify the
presence of moisture, acid, metallics and other contaminants
that will shorten compressor life if not corrected. In addition,
an analysis of the compressor vibration should be made
periodically.
