Two-stage compressors like the WFD551 can have
problems that never occur with single-stage machines.
Interstage pressure is an important indicator of the
condition of a two-stage compressor.
If interstage pressure is too high:
1. Second stage valves may be broken or leaking.
2. Second stage piston rings may be worn.
If interstage pressure is too low:
1. First stage valves may be broken or leaking.
2. First stage piston rings may be worn.
In most cases, problems with your Corken gas compressor
can be solved quite simply. This chart lists some of the
more frequent problems that occur with reciprocating
compressors along with a list of possible causes. If you
are having a problem which is not listed, or if you cannot
find the source of the problem, consult the factory.
Appendix D—Troubleshooting
Problem
Possible Cause
Low capacity
1, 2, 3, 4, 8, 15, 17
Overheating
1, 2, 3, 5, 6, 11, 16
Knocks, rattles and noise
1, 7, 9, 10, 11, 15
Oil in cylinder
8, 12, 15
Abnormal piston-ring wear
1, 3, 5, 6, 11, 15, 16
Product leaking through crankcase breather
8, 15
Product leakage
4, 8, 15, 17
Oil leakage around compressor base
17, 18, 19, 20
No oil pressure
19, 20
Excessive vibration
1, 7, 9, 10, 11, 13, 14, 28
Motor overheating or starter tripping out
21, 22, 23, 24, 25, 26, 27, 28
Ref.
Possible Causes
What To Do
1.
Valves broken, stuck or leaking
Inspect and clean or repair
2.
Piston ring worn
Inspect and replace as necessary
3.
Inlet strainer clogged
Clean or replace screen as necessary
4.
Leaks in piping
Inspect and repair
5.
Inlet or ambient temperature too high
Consult factory
6.
Compression ratio too high
Check application and consult factory
7.
Loose flywheel or belt
Tighten
8.
Worn piston-rod packing
Replace
9.
Worn wrist-pin or wrist-pin bushing
Replace
10.
Worn connecting-rod bearing
Replace
11.
Unbalanced load
Inspect valve or consult factory
12.
Oil in distance piece
Tighten packing nut — drain weekly
13.
Inadequate compressor base
Strengthen, replace or grout
14.
Improper foundation or mounting
Tighten mounting or rebuild foundation
15.
Loose valve, piston or packing
Tighten or replace as necessary
16.
Dirty cooling fins
Clean weekly
17.
4-way control valve not lubricated
Inspect and lubricate
18.
Leaking gas blowing oil from crankcase
Tighten packing
19.
Bad oil seal
Replace
20.
No oil in crankcase
Add oil
21.
Oil-pump malfunction
See oil pressure adjustment
22.
Low voltage
Check line voltage with motor nameplate. Consult power company
23.
Motor wired wrong
Check wiring diagram
24.
Wire size too small for length of run
Replace with correct size
25.
Wrong power characteristics
Voltage, phase and frequency must coincide with motor nameplate.
Consult with power company.
26.
Wrong size of heaters in starter
Check and replace according to manufacturer’s instructions
27.
Compressor overloading
Reduce speed
28.
Motor shorted out
See driver installation
29.
Bad motor bearing
Lubricate according to manufacturer’s instructions
Another cause for high interstage pressure is a low
compression ratio. Two-stage machines should not be
used in applications where the compression ratio is
below 5. To use two-stage compressors in this kind of
situation results in rapid ring wear, machine imbalance
and excessive horsepower. If you think you have a
problem in this area, consult factory.
D. Troubleshooting
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