Air bottle or Air receiver On board Ship

Main engine and auxiliary engine are the two prime components in a ship’s engine room, on which, the entire operation of the vessel is dependent. There are several other important machineries that are necessary to support these two main components; however, one equipment without which any of the above mentioned machines cannot do away with is an air bottle or air receiver.


What is an Air bottle or Receiver?

The air bottle or air receiver is a large container acting as a reservoir to store compressed air supplied by the main air compressor of the ship at high pressure. This compressed air is very important to start main engine or auxiliary engine.

air bottle

Purpose of Air Bottle

  • The high pressure is used for initial starting of the marine I.C engines present onboard vessel.
  • It also supplies control air to the marine engines.
  • Service air is supplied from the air bottle.
  • If the quick closing valves are air operated, safety air is supplied through air bottle.
  • Spring air for exhaust valve is supplied through air bottle.

Apart from above mentioned ones, there are several other uses as well.

What are the Air Bottle Mountings and Connections?

The general mountings and connection present on air bottle of a ship are:

  • Filling valve: This is a valve fitted in the supply connection from main air compressor to the air bottle.
  • Outlet to Main engine: An outlet valve and pipe is fitted for connection from air bottle to main engine for supplying air during starting.
  • Outlet to auxiliary engine: An outlet valve and pipe is fitted for connection from air bottle to auxiliary engines for supplying air during starting.
  • Auxiliary connection: Other auxiliary supplies connections such as service air, safety air etc. is also provided with isolating valve.
  • Relief valve: A relief valve is fitted on the air bottle to relieve excess pressure inside the bottle.
  • Drain valve: A drain valve is fitted at the bottom of the bottle to drain accumulated condensate from the receiver.
  • Fusible plug: A fusible plug is fitted in the bottle with a separate connection leading out of the engine room so that in the event of fire, this plug will melt and relieve all the air to the outside atmosphere.
  • Manhole door: A manhole door is fitted in the bottle to carry out inspection of the same.

You may also like to read-Different Parts of a Marine Air Compressor used on Ship


Book on Marine Aux. Machinery by H.D.McGeorge

Do you have info to share with us ? Suggest a correction

Get the Latest Maritime News Delivered to Your Inbox!

Our free, fast, and fun newsletter on the global maritime industry, delivered everyday.


  1. what are the ways to test an air bottle for leakage ?

    and why is the end piece tapperd before its welded to the shell ?

  2. if serious corrosion is detected in a starting air receiver and that receiver must be used explain how would determine the maximum pressure

  3. Hi there my question is other that the access door being easy to access by the orientation of the door being at 3 o’clock and 9 o’clock, is there another reason for the door being orientated along the horizontal plane?

Leave a Reply

Your email address will not be published. Required fields are marked *