Main Engine Decarb

 

1) Inform company and take permission.

2) Take immobilisation certificate from port state control.

3) Read the manual and have a tool box meeting with everyone involved in the job.

Discuss the complete procedure.

4) Prepare important tools and spares required for overhauling liner as given in the

manual

5) Prepare risk assessment and make sure all personal safety equipment are used

6) Shut starting air for Main Engine and display placards

7) Engage turning gear

8) Open indicator cocks for all the cylinders

9) Stop main lube oil pump and switch off the breaker

10) Once the engine jacket temperature comes down, shut the inlet water valve for

the unit to be overhauled

11) Keep other units in Jacket preheating system to maintain the jacket temperature

12) Drain the jacket water of the concerned unit from exhaust v/v and liner.

13) Shut the fuel oil to the particular unit whose liner is to be removed

14) Dismount the cylinder head using dedicated lifting tools

13) Discard the sealing ring from the top of the cylinder liner.

14) Turn the piston down far enough to make it possible to grind away the wear

ridges at the top of the liner with a hand grinder

15) Remove the palm bolts of the piston road connected to the crosshead.

16) Remove the inner bolts of the stuffing box(8 in number).

17) Turn the crankshaft so that piston moves towards tdc till d point when grooves

for attaching piston removal tool is out of the liner and accessible.

18) stop the turning gear. Attach the piston removal tool and pull it with the crane.

19) remove the piston and secure it with piston holding tool.

Put a cover in d scavenge space to prevent anything to fall in crankcase.

20) Pressure test the new piston. Piston rings to be renewed.

21) Stuffing box rings to be renewed.

22) liner to be checked for any wear. Calibration to be done. Lube oil to be sprayed

before installing the piston. Place the ring guide on the liner.

23) remove the cover from scavenge space.

24) lower the piston into the liner and guide the palm to the shoe. Insert two bolts

and secure the piston before removing the piston removal tool.

25) remove the piston removal tool. Tighten the palm bolts and stuffing box inner

bolts to required torque and lock using locking wire.

26) box back and do breaking in and running in