CAUSE – CORRECTION CODE

EFFECT / PROBLEM
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

Compressor does not start. * * * * * *

Compressor capacity not at

required rate. * * * * * * * * * * * * * *

Abnormal reduction of the

compressor suction pressure. * * * * * *

Abnormal pressures of gas

discharged from cylinders. * * * * * * * *

Abnormal temperatures of gas

discharged from cylinders. * * * * * * * * * * * *

Excessive noise or abnormal

* * * * * * * * * * * * * * * * * * * *
Table 16 – CAUSE AND EFFECT CHART

knocking.

Excessive vibrations in
compressor. * * * * * * * * * * * * * * * *

Excessive vibrations in the

ground around compressor. * *

Overheating of compressor
parts. * * * * * * * * * * * * * * * * * *

Overheating of driver. * * * * * * * *

Crank gear pump oil pressure

switch trips * * * *

Excessive oil consumption in the

sump. * *

Presence of oil in the distance

piece. *

Abnormal behaviour of
crosshead shoes, of crank gear * * * * * * * * * *
pump, bushes, shoulder rings.

Abnormal life of packing rings,

piston rod. * * * * * * * * * * * * *

Abnormal life of piston rings,

rider rings, cylinder liners. * * * * * * * * * * * * * *

Abnormal behaviour of cylinder

valves. * * * * * * * * * * * * * *
CHAPTER 9
TROUBLESHOOTING

Abnormal deposits inside

cylinders. * * * * *
CHAPTER 9
TROUBLESHOOTING

Table 17 – CAUSE AND CORRECTIVE ACTIONS

CAUSE
CORRECTION CAUSE OF PROBLEM POSSIBLE CORRECTION
CODE

1 Foundation too small. Increase foundation size.

2 A lot of water in the ground. Isolate compressor with damping systems.

3 Loosening of foundation bolt. Perform correct tightening of bolts after having checked
their status.
Restore correct compressor alignment.

4 Piping not properly anchored. Strengthen bracketing.

Add new support.
Check that piping flanged couplings are not constrained.

5 Driver too small in power. Reduce compressor capacity (i.e. by acting on interstage
recycle or other capacity control devices).
Replace driver.

6 Electric power supply inadequate. Restore correct setting of electric safety devices.
Tighten motor terminals correctly.
Restore correct motor excitation.
Increase motor supply voltage.

7 Suction line too small, too long or having equipment Reduce pressure losses to normal values by operating either
with excessive pressure drop. on the line or on the equipment.

8 Gas intake filter clogged. Clean the filter.

Reduce the amount of product to be separated, by operating
on the line or on the upstream plant.

9 Excessive pressure pulsation. Restore compressor design operating conditions.

Insert orifices in the piping.
Modify the size or the shape of the piping or add pulsation
suppressor devices.

10 Excessive carry-over of condensates in process gas. Reduce the maximum condensate level in the separators.
Increase frequency of liquid draining from separators.
Restore design operating conditions (pressures and
temperatures of process gas).
Clean separators.
Add drain valves at low points of gas piping where liquid
can accumulate.

11 Carry over of solid particles in process gas. Insert an intake filter, if not provided, or replace it with a
more adequate one.
Operate on the upstream plant, to prevent abnormal
quantities and qualities of solid matter from reaching the
separator.
Perform correct blowing of gas piping and of compressor
auxiliaries.
Improve efficiency of separator on compressor intake.
 CHAPTER 9
TROUBLESHOOTING

CAUSE
CORRECTION CAUSE OF PROBLEM POSSIBLE CORRECTION
CODE

12 Excessive vibration in crankshaft. Restore correct tightening of connecting rod bolts.

Restore correct tightening of flywheel to crankshaft.
Replace journal bearings.
Restore correct alignment of coupled machinery.
Rework the damaged shaft and install undersized bearings
or replace the shaft.

13 Incorrect assembly of components. Repeat assembly, following the correct sequence indicated
on the assembly drawings.

14 Wrong positioning of drive components. Restore correct positioning of driving system; comply with
the magnetic center of the electric motor, the various axial
clearances and the alignment in the axis of the shafts as
specified by the manufacturer.

15 Defective instrumentation or devices. Restore correct operation of the instruments or devices, or

replace them if necessary.

16 Defective operation of valve unloaders. Increase the pressure of the control gas.
Eliminate leakages in the control gas system.
Use a control fluid with a lower dew-point.
Clean the actuator stem or replace it if corroded or worn.
Replace worn seals.
Restore correct clearance in the actuator-unloader system.
Install the valves correctly on the cylinders.
Modify the valve unloader control system.

17 Final pressure of compressor higher than the normal Restore correct operation of overall by-pass.
operating value. Take action on plant equipment.
Remove any partial occlusion in discharge line.

18 Too long unloaded running of cylinders. Reduce the unloaded operation times.
Reduce compressor speed.

19 Loosening of flywheel or of driving pulley. Perform correct tightening, after having restored the mating
surfaces.
Restore correct alignment in the drive system.

20 Slippage of belts. Restore correct tension of belts.

Use belts all of the same length.
Bring compressor load back to rated value.
Restore correct alignment of compressor flywheel with the
driving pulley.
Use more suitable belts.

21 Loosening of cylinder valves. Tighten the valve cover bolting with torque specified in this
manual.
Correctly assemble the valves and the relevant cages on the
cylinders.
Avoid overheating of cylinders.
Restore the seat of the valves in the cylinder.
Avoid liquid and solid substances enter the cylinder.
CHAPTER 9
TROUBLESHOOTING

CAUSE
CORRECTION CAUSE OF PROBLEM POSSIBLE CORRECTION
CODE

22 Loosening of piston rod connection with crosshead Perform correct tightening of the rod after having restored
or with piston. or replaced damaged parts.
Avoid liquid and solid substances enter the cylinder.

23 Loosening of crosshead shoes or connecting rod Perform correct tightening after having restored or replaced
bolts. damaged parts.

24 Cylinder misalignment. Restore alignment.

25 Improper cylinder or rod packing lubrication. Use oil having the properties specified in this manual.
Restore correct level of oil in lubricator.
Stop lube oil leaks off the oil system.
Increase or reduce as necessary the oil rate to the cylinders.
Heat the oil and insulate the oil lines.
Use a different oil grade, if the compressor handles a gas
carrying solvents not known at the time of machine design.
Replace lubricator plungers.
Replace the check valve of oil injection quills on the
cylinder.

26 Crank gear pump oil pressure too low. Use oil having the properties specified in this manual.
Repair or replace the pressure gauge.
Set correctly the by-pass valve.
Restore the correct level of oil in the sump.
Remove contamination of water or air into the oil.
Stop leaks of lube oil off oil system.
Increase efficiency of oil cooler.
Set correctly the safety valve of the oil system.
Clean the filter.
Replace the crank gear pump.

27 Insufficient cooling. Increase the coolant flow rate.

Upgrade the cooling system and clean the heat exchanger
surface.
Use a less fouling coolant.
Stop any compressed gas leaks into the coolant system.

28 Poor working of oil scraper rings. Assemble oil scraper rings according to instructions.
Replace worn or scored oil scraper rings.
Replace worn or scored piston rod.

29 Excessive leakage of gas from packings. Correctly install the packing rings, as specified in this
manual.
Remove clogging from vent system.
Restore the normal pressure of gas recovery from stuffing
boxes.
Clear off dirt blocking packing rings inside the cups.
Restore correct clearance between packing rings and cups.
Replace worn packing rings.
Replace piston rod if worn of scored.
Restore correct cylinder alignment.
 CHAPTER 9
TROUBLESHOOTING

CAUSE
CORRECTION CAUSE OF PROBLEM POSSIBLE CORRECTION
CODE

30 Leakage of gas trough gasket. Apply adequate tightening torque to the fastening bolts.
Avoid overheating of parts holding the gaskets.
Avoid overloads on gaskets induced by plant components.
Replace damaged gaskets.
Use gaskets of different type.
Apply gasket of different material, if corroded.
Restore condition of the surfaces holding the gaskets.

31 Leakage of gas surfaces mating without gaskets. Restore or increase correct tightening of bolts fastening the
parts.
Recondition the state of the mating surfaces.
Use adequate seal paste.

32 Poor piston ring seal. Perform an accurate check on piston rings.

Remove grime blocking rings in their grooves.
Restore clearance between piston rings and their grooves.
Replace worn piston rings.
Recondition sliding surfaces.
Replace the cylinder liner.
Restore correct cylinder alignment.

33 Piston clearance outside specified limits. Restore correct assembly of components.

Replace worn or damaged parts.
Rework parts out of tolerance.

34 Corrosion of parts on which mechanical components Eliminate the corrosive agent.

slide or roll. Keep pressures and temperatures within values specified in
this manual.
Prevent contact of corrosive agent with these parts
Change the material of these parts.
Improve separation of condensates.
Investigate presence of eddy currents.

35 Corrosion of cylinder valve springs. Eliminate the corrosive agent.

Change the spring material.
Improve separation of condensates.

36 Excessive wear or scoring of sliding or rolling parts. Clean filters.

Improve efficiency of separators.
Change the lubricant grade.
Increase rate of lubricant.
Remove causes of overheating of the parts, which may be
due to: gas backflow, insufficient cooling and abnormal
operating conditions.
Restore correct clearances as specified in this manual.
Change material of sliding or rolling parts.
Restore correct alignment of components supporting the
damaged parts.

37 Scaling of antifriction metal lining. Avoid any entrainment in the oil such as water, air, etc.
Clean lube oil system.
Restore correct lubrication.
Replace parts having antifriction metal lining.
CHAPTER 9
TROUBLESHOOTING

CAUSE
CORRECTION CAUSE OF PROBLEM POSSIBLE CORRECTION
CODE

38 Oil leakage. Replace the seal ring on the crankshaft.

Restore correct seals, on the frame, with covers, shields and
crosshead extensions.

39

40