Air Compressors Flashcards
- With reference to main starting air compressors:
a) State 3 maintenance procedures that maintain their efficiency.
a) Regular replacement of the air suction filter.
Regular lubrication of motor bearings.
Using only OEM parts for replacement works.
- With reference to main starting air compressors:
a) State 3 maintenance procedures that maintain their efficiency. b) Describe the procedure for the manual starting of a compressor.
b)
Change the switch to manual position on the switch board.
Check the L.O sump level and condition.
Open the moisture drain valve.
Open the compressor discharge valve & charging valve of air bottle.
Open cooling water system valves.
Turn the compressor flywheel by hand (one turn).
Start the motor, after draining the moisture shut the drain valve.
Check the motor ampere consumed.
Check the pressure gauge readings.
Frequently drain the moisture.
When charging full, open drain valve and stop the compressor
- With reference to main starting air compressors:
a) State 3 maintenance procedures that maintain their efficiency. b) Describe the procedure for the manual starting of a compressor. c) State how deterioration in the efficiency would be effected.
c) If one compressor is on auto mode but it constantly running, and the main start air bottle is not charging properly.
- With reference to main starting air compressors:
a) State 3 maintenance procedures that maintain their efficiency. b) Describe the procedure for the manual starting of a compressor. c) State how deterioration in the efficiency would be effected. d) State 4 causes for deterioration in efficiency.
d) Blocked unlet filters.
Values seated incorrectly.
Work liners/piston rings.
- With reference to main starting air compressors:
a) State 3 maintenance procedures that maintain their efficiency. b) Describe the procedure for the manual starting of a compressor. c) State how deterioration in the efficiency would be effected. d) State 4 causes for deterioration in efficiency.
e) Describe a test for establishing performances.
e) Drain off a small amount of air from the air receiver and record the pressure left inside. Start the compressor and record now long it takes for the bottle pressure to increase, after to full or pre-determined level.
- With respect to 2-Stage reciprocating compressor used for air start purposes: a) State 4 reasons for a reciprocating compressor taking too long to fill the man air starting bottles.
a) There is a leak in the system.
Blocked air inlet filters.
Worn liners/piston rings.
Incorrectly seated valves.
- With respect to 2-Stage reciprocating compressor used for air start purposes: a) State 4 reasons for a reciprocating compressor taking too long to fill the man air starting bottles.
b) State 4 safety devices fitted to the air staring system of a large marine diesel engine.
b) Bursting disks, safety valves on every branch of the air start manifold.
Pressure relieving safety valves on intercoolers and after coolers.
Safety valves on main air starting bottles.
Bursting diaphragm on air compressors cooling jacket water.
- With reference to 2-Stage water cooled reciprocating main engine starting air compressors: a) Describe, with the aid of a sketch, a protective device fitted to the waterside of the intercooler or after cooler.
b) Explain why the device described in (a) is fitted.
b) To relieve pressure build up in the event of an air tube leak or cylinder liner cracked within the air compressor.
- With reference to 2-Stage water cooled reciprocating main engine starting air compressors: a) Describe, with the aid of a sketch, a protective device fitted to the waterside of the intercooler or after cooler.
b) Explain why the device described in (a) is fitted.
c) Briefly describe the possible consequences should the device described in (a) fail to operate.
c) If the device failed to operate, over pressure may occur within the jacket water cooling, resulting in potential rupture of the air compressor.
