#3 compressed air system

Question 1

Uses of compressed air

Answer 1

• starting main engine and generators
• deck equipment (air whistles, gang ways, lifeboat winches)
• maintenance work ( pneumatic tools, chipping machines etc)
• control instruments

Question 2

Pressures of compressed air

Answer 2

• starting = 30
• deck equipment =7
• maintenance work =7
• control instruments =1-7

Question 3

main air compressors

Answer 3

compress the air to 30-bar pressure and stored it in big air cylinders called air bottles or receivers. There will be two air receivers on board

Question 4

service air compressors

Answer 4

compress the air to 7 bar and stored in a smaller air bottle

Question 5

automatic control instruments

Answer 5

requires very clean air
taken from the service air bottle (at 7 bar) and reduced to 1 bar
control air had to pass through fine filters and
dehydrators to remove the dirt, oil and water content

Question 6

Emergency Air Bottle

Answer 6

contains a limited supply of air
main function is to supply compressed air to start a generator when the main air receivers are empty
run by an external source of power (small diesel engine)
must always be fully charged

Question 7

Drain valve

Answer 7

to drain moisture