070-450 IOM (NOV 13)
Page 22
XJF ROTARY SCREW COMPRESSOR
MAINTENANCE
5. Protect the compressor during long periods of
shutdown. If the compressor will be sitting for long periods
without running, it is advisable to evacuate to low pressure
and charge with dry nitrogen or oil. This is particularly true
on systems known to contain water vapor.
6. Preventive maintenance inspection is recommended
any time a compressor exhibits a noticeable change in
vibration level, noise, or performance.
CHANGING OIL
WARNING
DO NOT MIX OILS of different brands, manufacturers,
or types. Mixing of oils may cause excessive oil foam-
ing, nuisance oil level cutouts, oil pressure loss, gas or
oil leakage and catastrophic compressor failure.
Shut down the unit when changing oil. At the same time all
oil lter cartridges must be changed and all oil strainer ele-
ments removed and cleaned. The procedure is as follows:
1. Stop the compressor unit.
2. Lock out the motor starter.
3. Close the suction and discharge service valves
4. Using appropriate equipment, lower the compressor
pressure to 0 psig.
5. Open the drain valve(s) and drain oil into a suitable
container.
6. Drain the oil lter(s) and the oil coolers.
7. Remove the old lter cartridges, and install new ones.
8. Remove, clean, and reinstall elements in the strainers.
9. Evacuate the unit.
10. Open the suction service valve and pressurize the unit
to system suction pressure. Close the suction valve and
leak test.
11. Add oil.
12. Open the suction and discharge service valves
13. Remove the lockout from the motor starter.
14. Start the unit
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
MAINTENANCE SCHEDULE
This schedule should be followed to ensure trouble-free operation of the compressor unit.
FREQUENCY OR HOURS OF OPERATION (MAXIMUM)
MAINTENANCE
200
1000
5000
8000
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
n
Every 6 Months
Replace Filters
n n n n n n n n n n n
Clean Oil Strainers
n n n n n n n n n n n
Clean Liquid Strainers
n n n n n n n n n n n
Replace Coalescers
n n n
Check and Clean Suction Strainer
n n n n n n n n n n n
Check Coupling (a)
n
Annually Regardless of Operating Hours
Suction & Disch Flange Bolts (d)
n n n n n n n n n n n n n n n n n n n n n n
VFD Units Check Skip Freq. (f)
n n n n n n n n n n n n n n n n n n n n n n
Check Electrical Connections (b)
n n n n n n n n n n n n n n n n n n n n
Check Sensor Calibration (c)
n n n n n n n n n n n n n n n n n n n n n
Vibration Analysis (e)
n
Every 6 Months, More Frequently If Levels Increase
Replace Shaft Seal When Leak Rate Exceeds 7 - 8 Drops Per Minute
a. Check bolts, shim packs, center inserts, keys, and all bolt torques.
b. Check and torque all terminals in the processor and starter panel per the specication posted in the enclosure.
c. Check calibration of Slide Valve, Slide Stop, pressures and temperatures. Calibration should be conducted with NIST certied devices.
d. Verify tightness of bolts on suction and discharge anges. See table below for torque requirements.
e. Vibration measurement must be carried out continuously to obtain optimum preventative control on bearings. If not continuously controlled,
then every 6 months, more frequently if levels increase.
f. Units with varible speed drives - check for excess vibration and skip frequencies any time unit operating conditions change.
1. Based on metal to metal contact.
2. Based on: Gaskets: Garlock
®
Blue-Gard
®
3300; Bolts: class 8.8 or stronger hex head bolts, lightly oiled and clean
Compressor
Model
Motor Flange to
Compressor Tunnel
(1)
Compressor Flange to
Separator Flange
(2)
Bolt Size (in.) Torque (ft-lb) Bolt Size Torque (ft-lb)
XJF 95S,M,L 1/2 or 5/8 58 M20 X 2.5 107
XJF 120S,M,L 1/2 or 5/8 58 M20 X 2.5 150
XJF 151A,M,L,N 5/8 or 3/4 144 M22 X 2.5 167
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