Page 338 - Reciprocating Compressors Operation Maintenance

Troubleshooting Compressor Problems

TABLE 5-3 (CONTINUED)
TROUBLESHOOTING WATER-COOLED
RECIPROCATING COMPRESSORS

Observed Probable Cause or
Abnormal Condition Contributing Factor
Cooling-Water Sludged cylinder jackets need cleaning
Temperature Too High Heat exchanger or cooling tower needs cleaning
Jacket water pump not functioning
Inadequate cooling-water supply
Compressor Knocks Loose valve or unloader
Broken unloader control spring
Loose flywheel or sheave
Excessive main or crankpin bearing clearance
Loose piston rod nut
Loose motor rotor on shaft
Loose packing
Piston hitting head; insufficient clearance
Compressor Vibrates Improper grouting
Incorrect speed; excessive discharge pressure
Improperly supported piping
Defective capacity control; unloader stuck
Loose flywheel or sheave
Loose motor rotor on shaft
Source: Plant Engineering, October 12, 1978.

(text continued from page 318)

The problem becomes compounded; the leakage gets progressively
worse. The moving parts, that is, strips, channels or plates, may distort
due to warpage and lack of clearance due to high temperatures. Carbon
build-up occurs and the problem becomes even worse. Leakage may also
be caused by faulty valve seat gaskets, eroded valve seats, or malfunction
of the suction valve unloader.
Fortunately, there are inexpensive infrared devices that can speed up
the task of monitoring valve temperatures and allow us to take corrective
action when temperatures increase above normal. These temperature
measuring devices are accurate and easy to use. One such device should
be available at each plant. Valve cover temperature readings should be
taken and recorded on a form as shown in Figure 5-1 at least once every
operating shift. Contrary to popular belief, valves that start out as leakers