Video: Operation of Main Engine Starting Air System
The video shows the line diagram for main engine air starting system which comprises of – air bottle to provide 30 starting air, pilot valve to start the operation, turning gear interlock, automatic air start valve, air distributor, and cylinder head starting air valve.
Air supply is provided by opening the main air bottle valve. As the valve is opened, the air is passed through the pilot valve and acts on top of the automatic start valve, providing a positive closing. The other branch supplies air until the turning gear interlock as the interlock blocks the air to go further.
To start the main engine, first turning gear has to be disengaged. This will deactivate the interlock and the air will be supplied to the automatic start air valve.
Since there is a spring pressure and additional positive closing by the air supplied pilot valve, the air will not go further automatic start valve until the start command is given.
When the air start lever is operated in the ECR, the pilot valve shifts and blocks the air on top of automatic valve. It vents the line and there is no more positive closing.
Air passed from turning gear interlock pushes the spring, opens the valve and closes the vent.
Now the air is available in the cylinder head starting air valve manifold and in the distributor. The distributor consists of a negative type cam for positive overlap.
When the concerned unit number 4 distributor valve comes in the cam profile, air compresses the spring and the valve is opened to operate the same unit number 4 cylinder head starting air valve.
As the camshaft rotates, unit number 4 line is vented and the cylinder head starting air valve closes. Now unit number 1 valve will be in contact with the cam profile and the air is injected in this unit.
The air injection is done as per the firing order of the engine.
Video of Main Engine Starting Air System
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The information on this website is for general purposes only. While efforts are made to ensure accuracy, we make no warranties of any kind regarding completeness, reliability, or suitability. Any reliance you place on such information is at your own risk. We are not liable for any loss or damage arising from the use of this website.
About Author
Raunek Kantharia is a marine engineer turned maritime writer and entrepreneur. After a brief stint at the sea, he founded Marine Insight in 2010. Apart from managing Marine Insight, he also writes for a number of maritime magazines and websites.
Disclaimer :
The information on this website is for general purposes only. While efforts are made to ensure accuracy, we make no warranties of any kind regarding completeness, reliability, or suitability. Any reliance you place on such information is at your own risk. We are not liable for any loss or damage arising from the use of this website.
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I like to know the design system how to start up the engine ?
We hv ship marine 2nd hand engg n spare parts pls send to me query by mail [email protected]
Thank You for this interesting topic for my. I’m looking foreword and know, that this topic will be very good information (short information) for yang engineers or navigators.
I’m PETRAS PIKSRYS deep seas vessels navigator. My main education is navigate ocean going vessels and my second education is engineer ocean going vessels. I’m now, that topics like this is very good for all seafarers.
I am a diesel engine mechanic any question. Telling.
Dears
Thanks for this explanation
can you explain how the engine can be stop”shutdown”??