AIR COMPRESSORQ1. What is the use of air compressor on board ship? Ans: It is use to produce the compressed air and store the air in air bottle/ air receiver. Q2. What are the uses of the compressed air onboard ship? Ans: Starting main engine, Starting A/E, Service air, Control air, Whistle Air, Hydrophore tank charging, Pneumatic tools. Q3.What is the use of drain cock on an air receiver? Ans: Drain cock on receiver remove oil and water to prevent corrosion. To drain condensate and dirt deposited in air bottle. Q4. What check you will carry out while compressor is running. Ans: 1. check lubricating oil sump level 2. Lubricating oil pressure 3. Cooling water pressure 4. Discharge air pressure 5. Drain on each stage cooler 6. Motor ampere Q5. What will you do if you find that lubricating oil level in the crankcase has come down? Ans: stop the compressor and replenish the oil. Q6. Where does the air from the air compressor go to? Ans: To air receiver via air cooler. Q7. What precaution you will observe while working with compressed air. 1) Should not be directed toward the body 2) No leakage 3) Hoses and coupling in good condition 4) Pressure as required Q8. What are the precautions you will take while working on compressor? 1. Isolate the compressor. 2. Switch of the motor 3. Put men at work notice 4. Shut delivery valve 5. Shut cooling water valves Q9. What are safety devices are fitted on main air compressor. Ans: 1) Bursting disc 2) Relief valve after each stage 3) Drain vale for moisture/ Unloader valve Q10. What are the safety devices are fitted on air receiver? Ans: 1) Pressure relief valve 2) Drain valve 3) Air vent 4) Pressure gauge 5) Fusible plug if safety valve is not directly fitted on air receiver. 6) Low air pressure alarm