During maneuvering on a slow speed diesel engine vessel, a low starting air system pressure alarm is activated. Local starting air receivers' pressure gauges indicate proper pressures, and compressors are running and are 'loaded' up. What could cause the alarm?
ā¢ Starting air system layout from compressors ā receivers ā main starting valve ā distributor ā cylinder starting valves ā¢ How a stuck open valve or leak affects air pressure and compressor loading ā¢ Where a low starting air pressure alarm usually senses pressure in the system
ā¢ Look at each option and ask: Would this mainly affect pressure in the receivers or just the distribution of air to cylinders during starting? ā¢ If compressors are running and are described as 'loaded', what does that tell you about the actual pressure and air demand in the system? ā¢ Compare the local pressure gauge readings with the alarm: if they disagree, which component(s) in the chain are most likely at fault?
ā¢ For each choice, decide: Would this cause the receiver/system pressure to drop enough to trigger a low-pressure alarm? ā¢ Think carefully about the location of the alarm pressure switch versus the local gauges: are they sensing the same point in the system? ā¢ Verify which components (distributor valves, cylinder starting valves, main starting valve, alarm switch) primarily affect starting sequence and which affect overall system pressure indication/alarm.
No comments yet
Be the first to share your thoughts!