This document is valid for existing engine types
MAN B&W Diesel: MC, MC-C, ME, ME-C, ME-B and
MAN Diesel four-stroke GenSets: L16/24, L21/31, L27/38, L32/40, L23/30(H), L28/32(H)
Contents
1. Scope and field of application
2. Reference
3. Prior to laying-up
4. Engine room and control room
5. Auxiliary supply systems
6. Preservation of main engine
7. Preservation of auxiliary engines
8. Preservation of turbochargers
9. Connection and operation of dehumidifier for the main engine.
10. Connection of dehumidifier for the auxiliary engines.
11. Protection of electronic equipment
12. Equipment for preservation oil spraying
13. Maintenance of main engine preservation
14. Maintenance of auxiliary engine preservation
15. Preparation of turbocharger before recommencing service
16. Starting the main engine after the laying-up period
17. Starting the auxiliary engines after the laying-up period.
1. Scope and field of application
This recommendation deals with the procedure for laying-up of vessels for an unspecified period, where qualified supervision is needed for the engine room & the engines.
The recommendation should be used as guidance only. It is the shipowners responsibility to ensure proper maintenance and inspections during the laying-up period.
During the laying-up period, it is expected that the main engine and auxiliary engines are not operating and in cold condition as below:
The fuel oil system & the lubricating oil system are filled & not operating.
Cooling water system is filled and not operating.
The atmosphere inside the engines must be controlled by dehumidifiers and kept below 50 % RH.
Sufficient electrical power must be available from external source for maintenance use & monthly operation of one main lubricating oil pump.
2. Reference
Reference is made to the MAN Diesel Recommendation No 0743350-6.; Recommendation for laying-up of the vessels with main engine in warm condition, i.e. cooling water system heated by a continuously operating auxiliary engine.
3. Prior to laying-up
We strongly recommend making a laying-up check list to ensure that laying-up maintenance diverting from normal port stay routines is carried out correctly during the laying-up period & prior to the first engine start after the laying-up period.
3.1 Before stopping the main engine & auxiliary engines
Fuel system
Operate the main and auxiliary engines on MDO (Marine Diesel Oil), by following the steps below:
Follow the change-over process for changing from Heavy Fuel Oil (HFO) to MDO
When the change-over has been done, run the main engine on MDO at full load for one hour or at minimum 75% load for two hours to flush out heavy fuel oil from the injection pumps, high pressure pipes and fuel injectors and to clean the exhaust system.
Operate the auxiliary engines on MDO for a minimum of one hour for each engine to flush out heavy fuel oil from the injection pumps, high pressure pipes and injectors before laying-up by following the change-over process for changing from HFO to MDO.
Turbocharger
Soft blast clean the turbine side.
Water wash the turbine side(if turbine shaft vibrations are seen during increase in the speed after the drying period: continue water washing).
If necessary: Soft blast can clean the turbine side again.
Clean the compressor wheel by water washing.
Scavenge air cooler
If considered necessary, clean the scavenge air cooler air side in due time before laying-up as explained in the instruction manual.
3.2 After stopping the main engine & auxiliary engines
Keep the main lubricating oil pumps & the jacket cooling water pump running for at least 15 minutes after stopping the engine. This will avert overheating of the piston top & combustion chamber.
As the fuel oil system for the main engine is filled with MDO, assure that the valves for the fuel oil inlet pipe & fuel oil outlet pipe of the main engine are closed & the by pass valve is open. Close also the ball shut-off valve for each fuel oil pump in the fuel oil pump inlet line. The auxiliary engines can be changed back to HFO or continue operation on MDO till their final stop.
After stopping the auxiliary engines assure that the valves for the fuel oil inlet pipe & fuel oil outlet pipe of each auxiliary engine are closed & the by-pass valve is open.
If the main engine & auxiliary engines have separate fuel oil systems, the process should be made for both fuel oil systems.
Secure the closed valves in locked position to avert faulty operation during the laying-up period.
4. Engine room and control room
Keeping the recommended temperatures & humidity in the engine room & the control room will provide the best preservation of the mechanical & electronic equipment.
4.1 Engine room
Engine room temperature should be above 0°C
If the engine room temperature is below 10°C this might have an effect on the capacity of the dehumidifiers for the engines & larger dehumidifiers may be needed.
Keep the engine room well-ventilated.
4.2 Control room
Control room temperature: 20-25°C
Humidity: 40-50% RH
Air condition: Permanently on
5. Auxiliary supply systems
5.1 Fuel oil system
For the treatment & preservation of the fuel oils, it is suggested to contact the oil company for advice & recommendations.
High temperature (especially in tropical waters) and high water content in the fuel oils, both HFO and MDO, will increase the risk of microbial growth. To minimize this risk, it is important to observe the fuel oils and to keep the water content well below 0.3%. It can be recommended to consider the use of biocide in the fuel oil to avoid microbial growth.
Fuel oils might build up some acidic products during the oil aging process. These acidic products might cause corrosion. By adding, to the Day tank, a small percentage of antioxidation additive and anticorrosion additive suitable for this application, this could help to minimise this effect. After adding, circulate the fuel oil for one hour.
Once a month, it is recommended to analyse an HFO/MDO fuel oil sample at a laboratory for water content and microbial growth. The upper limit for the water content in fuel oils is 0.3%.
Once every six month, run the fuel oil circulating pump for one hour.
If the main engine & auxiliary engines have separate fuel oil systems, the process should be made for both fuel oil systems.
5.2 Jacket cooling water system (high temperature, HT)
Don’t drain the jacket cooling water system to avoid corrosion. Circulate the cooling water for one hour once a month.
It is expected that the jacket cooling water system is not exposed to temperatures below 0°C.
Add rust inhibitor to jacket cooling water system. After circulating the water, take a sample and analyse. Correct the condition if necessary. Follow the rust inhibitor manufacturers’ recommendation.
In the event of the jacket cooling water being exposed to temperatures below 0 °C, Glycol must be added to obtain sufficient protection. Before starting the engine the jacket cooling water system has to be drained off and refilled with treated fresh water.
5.3 Central cooling water system (low temperature, LT)
Don’t drain the central cooling water system to avoid corrosion. Circulate the cooling water for one hour once a month.
It is expected that the central cooling water system is not exposed to temperatures below 0°C.
Add rust inhibitor to central cooling water system. After circulating the water, take a sample and analyse. Correct the condition if necessary. Follow the rust inhibitor manufacturers recommendation.
In the event of the central cooling water being exposed to temperatures below 0 °C, Glycol must be added to obtain sufficient protection. Before starting the engine, the central cooling water system has to be drained off and refilled with treated fresh water.
5.4 Control air supply system
Drain the system for any condensate water. The valves for the control air & manoeuvring air supply to the engine should be closed.
6. Main engine preservation
Main engine preservation should be performed immediately after laying-up the vessel.
Preservation maintenance should be performed regularly during the entire laying-up period.
6.1 Preservation oil
All larger oil companies offer usable preservation oils. Some examples are listed below. Other preservation oils with corresponding qualities can be used.
It is of the outmost importance that the preservation oils can be dissolved in the main lubricating oil without damaging the properties of the lubricating oil. Please contact your main lubrication oil supplier for suggestions;
Esso Rust Ban 392
Tectyl 502-C, 930
Mobilarma 500
Dinitrol 40
BP Protective oil 20
Chevron EP Industrial oil 100 – 150
Shell Ensis Engine Oil SAE 30W
Leave the lubricating oil system running while turning the crankshaft.
Heating of the lubricating oil is not needed during the laying-up period.
Once in a month after stopping the purifier, test the lubricating oil sample for water content(MAN Diesel’s upper limit is 0.2%). Test onboard and maintain a record of the water content level.
As an alternative, it is suggested to use a laboratory to test the oil samples for water content.
6.3 Separate camshaft lubricating oil system & hydraulic power supply oil system
Once in a month after stopping the purifier, test the lubricating oil sample for water content(MAN Diesel’s upper limit is 0.2%). Test onboard and maintain a record of the water content level.
As an alternative it is suggested to use a laboratory to analyse the oil samples for water content
6.4 Cylinder Oil lubricators
Shut off the cylinder oil inlet supply to the lubricator.
6.5 Exhaust valves
During the lay-up period, the exhaust valves will open & remain open if the ship control/working air system is shut down during the lay-up period. The wall surfaces of the exhaust valve air spring chamber required protection against corrosion within the laying up period. The surfaces can be secured with system oil as explained below. Below preservation methods for MC & ME engines are separated.
The hydraulic oil for the exhaust valve activation is for both the engine types continuously refreshed via an orifice at the top of the exhaust valve. The changed oil flows for the MC/-C version directly to the top of the spring air piston. For an ME/ME-C exhaust valve, the drain is through internally directly to the common drain line connection.
MC/MC-C/ME-B engines
After the final engine stop, keep the main lubrication oil pump running and perform the following:
One by one remove the exhaust valve air spring line and puncture the non-return valve (please note that an oil/air mixture will escape through the punctured non-return valve). Once the spring air chamber volume has escaped through the non-return valve, the exhaust valve opens, and the part of the air spring chamber above the air piston is filled with system oil provided by the running lube oil pump.
When all exhaust valves have been opened and the spring air chamber filled with oil the air spring non-return valves should be removed. Through the hole for the removed non return valve, sprinkle preservation oil into the air spring space below the air spring piston. Fit the non-retum valve here after.
The above procedure should only be performed once. At each monthly start of the main lube oil pump for engine turning, the air spring chamber will automatically be refilled.
ME/ME-C engines
After the final engine stop and main lube oil pump stop, the exhaust valves are opened one by one by puncturing the non-return valve in the spring air inlet.
With the open exhaust valves, the common drain line from each exhaust valve is taken off. Oil can be filled into the space above the air piston in following way:
1. Connect a container/funnel to the drain hole through a flexible hose
2. Level the container/funnel above the air spring chamber and fill oil into the container
3. Fill continuously till no more oil runs into the air spring chamber
4. Lower the container/funnel below the air spring chamber in order to drain excess oil prior to dismantling the flexible hose (thereby oil spill is eliminated)
5. Protect the chamber below the air piston as explained for the MC/-C exhaust valves
The above procedure shall only be done once. After 6 months, it is recommended to refill the air spring chamber above the air piston as explained in step 1-4. This is recommended as the space is not filled automatically during main lube oil pump operation.
6.6 Fuel oil injection pumps
The fuel oil injection pumps must be separated from the fuel oil supply line by closing the inlet valves for each pump. The MDO filled pump housings and pump injection components will be protected against corrosion.
MC/MC-C engines
Lift all the fuel roller guides clear from the cams by utilizing the lifting tool in the roller guide housing.
For the MC/MC-C engines with fuel oil injection pumps with variable injection timing VIT.
Safeguard the following spaces of the pump with the preservation oil:
A. Toothed bar for the fuel regulation(index rod) & toothed bar for timing(VIT rod).
Loosen and remove the unions and pointers around the toothed rods from the fuel pump housing. Move the toothed bars in and out simultaneously while applying preservation oil to the bars.
B. VIT regulating guide.
At the fuel pump housing base, a plug restrict access to the VIT controlling guide.
Preservation oil can be applied to the regulating guide through the bore and restricted by the mentioned plug.
C. Space between pump barrel and top cover.
The drain(generally an outer drain line) from the space above the pump barrel should be removed. Through the open drain hole, preservation oil is sprayed into the mentioned space. Space between pump barrel and top cover.
D. Dismantle the cover on the fuel pump base & spray preservation oil onto the sealing cap, lower end of the plunger & bottom flange of the fuel oil injection pump. Remount the cover.
E. For the preservation of the fuel & exhaust gear, dismantle the covers on the camshaft housing & spray preservation oil onto the springs & upper parts of the roller guides. Remount the covers.
ME/ME-C/ME-B engines
Dismantle the sensor & spray preservation oil onto the tapered cap & lower part of the plunger & bottom surface of the barrel. Remount the sensor.
6.7 Fuel injection valves
We do not recommend overhauling and re-installing the fuel injectors one by one, for the following reasons:
Overhaul of the fuel injectors without engine operation shortly after will increase the risk of trapping air in the system. Trapped air causes internal corrosion.
The fuel injectors can only be filled up with the oil after re-installation by opening the ball valve in the injection pump inlet line. If the fuel oil feed and circulation system is common for auxiliary engines and the main engine, HFO operation of the auxiliary engines will cause this fuel media to fill the just overhauled injectors of main engine.
Any leaks following the injector overhaul or reinstallation may not be found during the laying-up period. The non-return valve located in the re-circulation line from each set of fuel injection valves is expected to make a tight closing, but in case of a leak, the closed ball shut-off valve in the fuel oil pump inlet line will avert HFO to fill the fuel injectors during the laying-up period.
6.8 Mechanical governor
Follow the governor manufacturers preservation instructions.
If no preservation directions are available, the following directions can be used, for guidance only:
Exchange the lubricating oil in the governor with the new lubricating oil with same property specifications.
6.9 Reciprocating parts on the outside of the engine
Put rust preservation oil onto all reciprocating parts on the outside of the engine(fuel index rods, VIT index rods & fuel-rack links, etc).
6.10 Outside machined surfaces
Put Tectyl 502C onto all the machined surfaces on the outside of the engine.
6.11 Crankcase relief valves
Follow the maintenance instruction from the manufacturer.
If no information is available related to the rust protection of the relief valve, it can be suggested to spray the flame arrester steel plates with preservation oil, Dinitrol 40 or similar.
Only protect the relief valve with the proper protection in the event that painting, welding or grinding work is taking place nearby which can damage the relief valve.
6.12 Auxiliary blowers
Keep the electrical heating of the auxiliary blower motors running continuously.
6.13 Cooling water system for air cooler
If the air cooler is cooled by sea water, we recommend closing the sea water inlet and outlet valves to the cooler and dismantling the pipes to the air cooler.
Connect hoses for fresh water flushing to the flanges of the cooler. When the cooler has been flushed sufficiently with fresh water, fill the cooler with fresh water with added rust inhibitor. Seal off the lower flange and fixate the end of the hose from the upper flange to a level one meter above the cooler. The opening of the hose must not be blocked so the water is able to expand without damaging the cooler.
6.14 Piston rod stuffing boxes
Clean the scavenge air compartments below the liners & the air receiver itself shortly after laying-up. To neutralize any condensed acid in the oil trapped in the stuffing boxes, pour cylinder lubricating oil into each stuffing box while turning the crankshaft.
6.15 Components inside the engine
When carrying out preservation of the inside of the engine, keep the main lubricating oil pumps and camshaft oil pumps (if any) running until turning of the crankshaft has is completed.
Before carrying out the first preservation: Open up the scavenge air receiver and ventilate for minimum one hour. Clean the scavenge air chamber before starting preservation.
Preservation of the scavenge air chamber, together with cylinder liners, pistons rods & piston crowns
Put preservation oil onto the cylinder liner walls & piston crown top through the scavenge air ports when the piston is in bottom position.
Put preservation oil onto the piston rings while turning the crankshaft. Repeat once for each cylinder. From start to finish of this procedure, the crankshaft should be turned exactly 3% revolutions in all.
Stop lubricating oil pumps and camshaft oil pumps (if any). Let the lubricating oil in the crankcase drain off for minimum 1 hour before preservation of the crankcase.
Preservation inside the crankcase
Spray preservation oil onto the surfaces of the inside reciprocating parts, guide rails, chain drive, chain wheels, etc., & close covers tight.
Preservation of camshaft housing
Spray preservation oil onto the camshaft together with cams, rollers & roller guides, & remount covers.
6.16 Main engine exhaust pipe and crankcase venting pipe
Wrap the main engine exhaust pipe in the top of the funnel during the laying-up period to save against rain & dust.
Insert a blind flange between the crankcase & the crankcase venting pipe. This is essential for the preparation of connecting the dehumidifier.
Should the top of the venting pipe be exposed to rain & dust, it is suggested to cover the venting pipe top.
6.17 Starting Air distributor
Dismantle the starting air distributor & apply lithium grease onto the inside parts for preservation. Set up the starting air distributor according to the instruction manual.
6.18 Main starting air pipe
Maintain the main starting air pipe dry: Remove the end cover of the pipe, insert dehumidifying vapour powder into the pipe & remount the end cover.
6.19 Exhaust gas receiver
After separating the turbocharger gas admission pipe, blank off the exhaust gas receiver outlet with a steel plate cover of 3-5 mm thickness. Modify the cover to the flange of the compensator.
6.20 Turbocharger and exhaust pipe
Blank off the connection between the turbocharger outlet & the exhaust pipe with steel plate cover of 3-5 mm thickness. The purpose of putting the steel plate cover is to avoid dust & to protect the turbocharger from rain water if the exhaust system water traps fail.
For turbocharger preservation, see section 8.
6.21 Connection of dehumidifiers
Connect & operate the dehumidifiers as described in section 9.
7. Preservation of auxiliary engines
Auxiliary engine preservation must be performed immediately after the laying-up of the vessel.
Preservation maintenance must be performed regularly during the entire laying-up period & dehumidifier must be connected. See section 9 & 10.
7.1 Lubricating oil system
It is expected that sufficient electric power is available to run the lubricating oil pump.
Keep the pre-lubricating oil pump running while turning the crankshaft.
Heating of the lubricating oil is not needed during the laying-up period.
Start the lubricating oil purifier and the purifier pre-heater 24 hours before the monthly turning of the crankshaft.
Start the pre-lubricating oil pump 1 hour prior the monthly turning of the crankshaft. Turn the crankshaft 3% revolutions during the preservation work. Do not turn the crankshaft after the preservation work have been finished.
Once in a month, after stopping the purifier, test the lubricating oil sample for water content (MAN Diesels’ upper limit is 0.2%). Test onboard & maintain a record of the water content level.
As an alternative it is recommended to use a laboratory to test the oil samples for water content.
7.2 Mechanical governor
Follow the governor manufacturer’s preservation instructions.
If no preservation recommendations are available, the following instructions can be used, for guidance only:
Change the lubricating oil in the governor with new lubricating oil with same property specifications.
7.3 Reciprocating parts on the outside of the engine
Put rust preservation oil onto all reciprocating parts on the outside of the engine (fuel index rods, fuel-rack links, regulating shaft, etc.).
7.4 Outside machined surfaces
Put Tectyl 502C onto all machined surfaces on the outside of the engine.
7.5 Valve gear
Remove covers to valve gear & apply preservation oil & remount covers.
7.6 Preservation inside the crankcase
Remove the covers to the crankcase & sprinkle preservation oil onto the surfaces of the inside reciprocating parts, gear wheels & machined surfaces & remount the covers. The dehumidifier must be stopped during the preservation work.
7.7 Preservation of camshaft housing
Remove the covers to the camshaft housing & sprinkle preservation oil onto the camshaft including cams, rollers & roller guides & remount the covers.
7.8 Preservation of cylinder liner, piston crown and piston rings
Dismantle the indicator valves from the cylinder heads and add approximately 1/3 litre of preservation oil into each cylinder. Refit the indicator valves and open the valves. After turning of the crankshaft has finished, close the indicator valves.
Note:- For L16/24 without indicator valves, dismantle the fuel injection valves.
7.9 Turbocharger and exhaust pipe
Blank off the connection between turbocharger outlet to the exhaust pipe with the steel plates of 3-5 mm thickness. The purpose of these steel plates is to avoid dust & to save the turbocharger from rain water if the exhaust system water traps fail. For turbocharger preservation, see section 8.
7.10 Auxiliary engine exhaust pipe & crankcase venting pipe
Cover the auxiliary engine exhaust pipe in the top of the funnel during the laying-up period to save against rain & dust.
Insert a blind flange between the crankcase & the crankcase venting pipe. This is required for the preparation of connecting the dehumidifier.
Should the top of the venting pipe be exposed to rain & dust, it is suggested to cover
the venting pipe top.
7.11 Scavenge air receiver
Keep a bag of Silica gel inside the scavenge air receiver. It is essential to place a collecting tray for water underneath the Silica gel bag to prevent spot corrosion.
7.12 Alternator
During standstill, the alternator heating elements must be connected or similar heating must be installed to avoid damp condensation inside the alternator. The heating of the alternator must be continuously running during the laying-up period.
Corrosion protection must be done on machined surfaces, on bearing parts, on the shaft & on bearing gaskets.
The bearings should be filled with protective oil, Mobilarma 524 or similar.
7.13 Connection of dehumidifier
Connect & operate dehumidifier as explained in section 9.
8. Turbocharger preservation
Contact the turbocharger manufacturer before dismantling and preservation of the turbocharger.
Follow the turbocharger manufacturer’s recommendations. The following scope of preservation work is for guidance only.
8.1 Preservation
Close the lubricating oil inlet valve or blank off inlet pipe to turbocharger.
Disassemble the gas admission casing, silencer & insert piece.
Disassemble the rotor, & nozzle ring according to the instruction manual.
Remove deposits on all gas spaces & on turbine inlet & outlet.
Clean the rotor & the nozzle ring with boiling water till all deposits have been removed.
Put preservation oil to the rotor & the nozzle ring. All surfaces must be dry before putting the preservation oil. The preservation oil should be soluble in the lubricating oil.
Store the rotor & the nozzle ring in a plywood box with a cover in a dry storage place. Make sure that the rotor is supported in the area of the journal bearings only. The supporting area must be covered with the thin metal sheet made of brass. Put preservation oil before the rotor is placed in the support. The compressor wheel & turbine blades must not have any contact to other parts.
Store the removed casings & silencer in a dry storage place.
Apply preservation oil onto the bearings & inside of the bearing casing & cover all openings.
Blank off the turbine inlet & outlet flanges & compressor flange on the turbocharger casing with steel plates of 3-5mm thickness.
8.2 Maintenance of turbocharger preservation.
Contact the turbocharger manufacturer & follow the turbocharger manufacturer’s recommendations.
The following scope of maintenance work is for guidance only:
- Inspect the turbocharger casing & all disassembled parts on a monthly basis. If necessary, put preservation oil.
8.3 Alternative for the first six months of the laying-up period
As an alternative to dismantle the turbocharger and make the preservation as described in 8.1, the turbocharger can stay assembled for the first six months of the laying-up period. However, the following preparation is required:
Disassemble the gas admission casing & blank off the inlet to the turbine with steel plates of 3-5mm thickness.
Blank off the turbine outlet flanges to the funnel with steel plates having thickness of 3-5mm.
Cover the silencer firmly with a tarpaulin.
The lubricating oil inlet must be connected to the turbocharger and lubricating oil inlet valve open.
During the monthly running of the lubricating oil pump, the cover to the turbine inlet should be dismantled. Inspection can then be made, & the rotor must be turned to dispense lubricating oil evenly in the bearings.
After stopping the lubricating oil pump, inspect and remount the cover.
9. Connection and operation of dehumidifier
9.1 Principles for connecting the dehumidifier and recommended system
The dehumidifiers must be connected to the engine by means of flexible hoses. It is recommended to use steel wire reinforced plastic hoses. Same type as normally used for ventilation systems. The hoses should not be longer than necessary, & sharp bends should be avoided.
It is recommended to use one dehumidifier for circulating the dry air through the scavenge air chamber and exhaust gas receiver and one dehumidifier for circulating dry air through the camshaft housing, chain case and crankcase. If the chain case is placed in the centre of the engine, it is necessary to use two dehumidifiers to circulate the dry air through the camshaft housing, chain case and crankcase
9.2 Dehumidifier principle and recommended type
There are mainly two dehumidifier principles:
Absorption type:
- The humid air(process air) is circulated in the closed system through an absorber element which dries the air. The absorber element is continuously turned & in another chamber heated air(regenerating air) is blown through the absorber element in order to remove the water from the absorber element. This type is recommended.
Condenser type:
- The humid air (process air) is passing a condenser, where by cooling the air, the water condensate. The condenser type is not as efficient at low temperature as the absorption type and is not recommended.
The principle of the recommended absorber type dehumidifier
9.3 Choosing dehumidifiers
The dehumidifiers must have sufficient capacity to keep the humidity in the engine below 50% RH. The needed capacity of the dehumidifier may vary since the efficiency of the dehumidifier is depending on the ambient temperature and humidity.
When starting the dehumidifiers, the humidity of the air in the engine should be below 50% RH within a maximum of 48 hours. If the humidity of 50% RH is not reached, the system must be investigated and checked if it is connected incorrectly. It is also a possibility that the capacity of the dehumidifiers is insufficient, and it could be necessary to find the proper sizeof the dehumidifiers by experience.
Note:- Capacity of dehumidifiers deviated air at max. 75% RH. If 95% RH the needed capacity might increase around 50%.
10. Connection of dehumidifier for the auxiliary engines.
For dehumidifying the auxiliary engines, one dehumidifier of the size of 50 m3/h rated air should be sufficient.
The dehumidifier & auxiliary engines are to be connected with hoses as shown in Figure
11. Protection of electronic equipment
It is instructed to keep the cabinets for electronic equipment closed during the laying-up period to safeguard against mechanical damage of the electronics, dirt & static electricity.
11.1 Electronic equipment on the main engine
Vapour corrosion control must be applied inside all the cabinets for electronic equipment. Install capsules according to lifespan & protective range of a capsule
All cabinets for the electronic equipment must be closed & cable glands must be tight. Open holes in cabinets must be sealed air tight.
11.2 Electronic equipment in the control room
Air conditioning must be running permanently to keep the temperature between 20-25°C.
The humidity of the air should be maintained between 40-50 % RH.
11.3 Examples of vapour corrosion control suppliers
www.cortecvci.com
Model: Cortec VpCI 101
Description: Impregnated foam device
Silica gel desiccant packs
www.zerust.co.uk
Model: Zerust Capsules, see lifespan and protective range Figure 6.
Description: Designed to protect electronic components inside of enclosures
11.4 Protection during maintenance & repair works
All cabinets for the electronic equipment must be closed & holes sealed air tight when grinding, welding, painting or cleaning is carried out on the engine or close to the engine.
If welding on the engine is required, the ground clamp cable must have good electrical contact & should be placed as close to the welding arc as possible. The welding power supply must have an suitable earthing device.
12. Equipment for preservation oil spraying
It is instructed to use an oil sprayer to apply preservation oil onto the components inside the engine. A portable oil sprayer, ex. type ME3610FSP from MESTO or similar, is suggested. The oil sprayer can be charged with 6 bar compressed air & if compressed air is not available in the engine room when the maintenance of the preservation of the engines are to be done, a small portable compressor can be handy.
During the preservation work, it is suggested to wear, oil resistant gloves, eye protection, respiratory protection equipment, proper clothing & safety shoes.
Normal safety precautions & procedures should be followed when entering the engine.
13. Maintenance of main engine preservation
Regular preservation maintenance is essential during the entire laying-up period.
13.1 Visual inspection (monthly)
Inspect the entire engine inside & outside, without turning the crankshaft, to reveal any corrosion or water contamination. Remove signs of the corrosion, if any. Clean up after removing.
Apply preservation oil to inspected components.
Inspect the engine components for corrosion, particularly cylinder liners, piston rods, cross head, guide rails and chain drive.
Remove signs of corrosion, if any. Clean up after removing. Apply preservation oil to the components.
Inspect the upper parts of the piston crowns, piston ring packs & cylinder liner from the inside of the scavenge air receiver through the scavenge air ports.
Inspect the inside of camshaft housing, camshaft, cams, rollers & roller guides.
13.2 Engine components and turning of crankshaft (monthly)
Check the entire inside of the engine prior starting the main lubricating oil pumps & camshaft lubricating oil pumps.
To avoid corrosion of engine components which are not directly accessible for the visual inspection, i.e. bearings, journals, cylinder liners, piston rings, etc., and to avoid the crankshaft to settle in the same position, turn the crankshaft 3/2 revolutions once a month.
The main lubricating oil system must be operated for one hour, lubricating oil purifiers and pre-heaters for 24 hours before the crankshaft is turned.
Note:- Stop and disconnect the dehumidifier before starting the lubricating oil pump, during crankcase inspection before turning and when turning the crankshaft. Reconnect & operate the dehumidifier immediately after applying preservation oil and closing the crankcase doors.
Preservation of the scavenge air chamber, including cylinder liners, pistons rods & piston crowns
Spray preservation oil onto the cylinder liner walls & piston crowns through the scavenge air ports when the pistons are in bottom position.
Fill the top of the piston crowns with a special type of vaporising preservation oil. This will protect the inside of the cylinder covers.
Sprinkle preservation oil onto the piston rings when passing the scavenge air ports while turning the crankshaft.
Repeat once for each cylinder. From start to finish of this procedure, the crankshaft must be turned exactly 3/2 revolutions in all.
After the turning has been completed, spray the piston rods, stuffing boxes and the outside of the cylinder liner with preservation oil.
Preservation inside the crankcase
Stop the main lubricating oil pumps and purifiers after completing crankshaft turning. Let the lubricating oil drain off for a minimum of 1 hour. Sprinkle preservation oil onto the surfaces of inside reciprocating parts, guide rails, chaindrive, chain wheels, etc. Close the crankcase doors tightly.
Preservation of camshaft housing
Inspect the camshaft before starting the camshaft lubricating oil pumps prior to preservation of the components inside the engine.
If the engine has a separate camshaft lubricating oil system, operate the camshaft lubricating oil pump (cold oil) to circulate the lubricating oil along the system while the main lubricating oil pumps are running(one hour). Do not stop the pumps till the crankshaft turning process has been completed.
Let the lubricating oil drain off for a minimum of one hour after stopping the lubricating oil pumps. Dismantle the camshaft housing covers & spray rust preventing oil onto the camshaft including cams, rollers and roller-guides. Remount the housing covers.
After completing the monthly turning and preservation procedure
After stopping the purifier, test oil samples from the main lubricating oil & camshaft lubricating oil/hydraulic power supply oil (ME/ME-C/ME-B) for water content (MAN Diesel’s upper limit is 0.2%). Test onboard and keep a record of the water content level.
As an alternative, it is recommended to use a laboratory to test the oil samples for water content.
13.3 Hydraulic power supply oil system (monthly)
ME/ME-C and ME-B engines:
During the monthly running of main lubricating oil pumps, run the start-up pumps(cold oil) for 1 hour to pressure rise the lubricating oil in the HPS system. Make a visual inspection of the HPS system.
13.4 Reciprocating parts on the outside of the engine(monthly or as required)
Put rust preservation oil onto all reciprocating parts on the outside of the engine(fuel index rods, VIT index rods & fuel-rack links, etc.).
13.5 Outside machined surfaces (monthly or as required)
Put Tectyl 502C onto all machined surfaces on the outside of the engine.
13.6 Crankcase relief valves (monthly or as required)
Follow the maintenance recommendations from the manufacturer.
If no information is available related to the rust protection of the relief valve, it can be recommended to spray the flame arrester steel plates with preservation oil, Dinitrol 40 or similar.
Only cover the relief valve with the proper protection in the event that painting, welding or grinding work is taking place nearby which can damage the relief valve.
13.7 Auxiliary blowers
Keep the electrical heating of the auxiliary blower motors running continuously.
13.8 Main starting air pipe (monthly)
Replace the dehumidifying vapour powder in main starting air pipe.
13.9 Exhaust gas receiver (monthly)
Inspect the exhaust gas receiver.
13.10 Dehumidifier (daily, monthly)
Daily!
Record the humidity, temperature and operating hours of dehumidifying process in the maintenance log book. The readings are to be taken either from the outlet hoses or from the permanently fitted hygrometer and thermometer, for the camshaft housing (if any), crankcase and scavenge air chamber.
If the humidity level in the engine exceeds 50% RH, check the dehumidifier.
For operation and maintenance of the dehumidifier, follow the manufacturer’s instructions.
Diagram for connection of dehumidifier and recording sheet.
Monthly!
Calibrate the hygrometers.
13.11 Spare parts and maintenance tools as required)
Inspect spare parts and maintenance tools regularly.
13.12 Intermediate shaft and stern tube bearings (monthly)
Prior to the monthly crankshaft turning, assure that all bearings in the propeller shaft system are lubricated.
14. Maintenance of auxiliary engine preservation.
14.1 Lubricating oil system (monthly)
Start the lubricating oil purifier and the purifier pre-heater 24 hours before the monthly turning of the crankshaft.
Start the pre-lubricating oil pump 1 hour prior the turning of the crankshaft. Keep the pre-lubricating oil pump operating while turning. Heating of the lubricating oil is not required during the laying-up period.
Turn the crankshaft 3/2 revolutions during the preservation work. Do not turn the crankshaft after the preservation work has been finished.
Once in a month after stopping the purifier test lubricating oil sample for water content(MAN Diesel’s upper limit is 0.2%). Test onboard & maintain a record of the water content level.
As an alternative, it is instructed to use a laboratory to test the oil samples for water content.
14.2 Mechanical governor (once every six months)
Follow the governor manufacturer’s preservation instructions.
If no preservation suggestions are available, the following instructions can be used, for guidance only:
Change the lubricating oil in the governor with new lubricating oil with same property specifications.
14.3 Reciprocating parts on the outside of the engine(monthly)
Inspect & put rust preservation oil onto all reciprocating parts on the outside of the engine(fuel index rods, fuel-rack links, regulating shaft, etc.).
14.4 Outside machined surfaces (monthly)
Inspect all machined surfaces on the outside of the engine & put Tectyl 502C if required.
14.5 Valve gear (monthly)
Remove covers & inspect the valve gear & apply preservation oil & remount covers.
14.6 Preservation inside the crankcase (monthly)
Inspect the inside of the crankcase before starting the pre-lubricating oil pump.
Start the pre-lubricating oil pump 1 hour prior the turning of the crankshaft. Turn the crankshaft 3/2 revolutions during the preservation work.
Sprinkle preservation oil onto the surfaces of the inside reciprocating parts, gear wheels & machined surfaces & remount the covers. Do not turn the crankshaft after the preservation work of the crankcase have been finished.
Note:- Stop & disconnect the dehumidifier before, starting the pre-lubricating oil pump, during crankcase inspection, before turning and when turning the crankshaft. Reconnect and operate the dehumidifier immediately after applying preservation oil and the covers have been remounted.
14.7 Preservation of camshaft housing (monthly)
Remove the covers to the camshaft housing, make inspection & sprinkle preservation oil onto the camshaft including cams, rollers & roller guides while turning the crankshaft & remount the covers.
14.8 Preservation of cylinder liner, piston crown and piston rings (monthly)
Dismantle the indicator valves from the cylinder heads and add approximately 1/3 litre of preservation oil into each cylinder. Refit the indicator valves and open the valves. After turning of the crankshaft has finished, close the indicator valves.
Note:- For the L16/24 without indicator valves(optional), dismantle the fuel injection valves.
14.9 Dehumidifier (daily, monthly)
Daily!
Record the humidity, temperature and operating hours of the dehumidifying process in the maintenance log book. The readings are to be taken either from the outlet hoses or from the hygrometer and thermometer fitted permanently in the outlet dummy cover of the crankcase.
If the humidity in the engine above 50% RH, check the dehumidifier.
For operation and maintenance of the dehumidifier, follow the manufacturer’s instructions.
Diagram for the connection of dehumidifier & recording sheet,
Monthly!
Calibrate the hygrometers.
14.10 Scavenge air receiver (monthly)
Replace the bag of the Silica gel inside scavenge air receiver. Empty the collecting tray for water.
14.11 Jacket cooling water system (monthly)
Circulate the cooling water for one hour.
14.12 Central cooling water system(monthly)
Circulate the cooling water for one hour.
14.13 Auxiliary engine exhaust pipe
Inspect the top cover of the funnel for the exhaust pipe of the of the auxiliary engine on a regular basis.
14.14 Alternator
Check the alternator on a regular basis & assure that the heating elements are operating proper.
14.15 Maintenance tools & spare parts
Check the maintenance tools & spare parts for the auxiliary engine on a regular basis.
15. Preparation of turbocharger before recommencing service
Contact the turbocharger manufacturer before commissioning the turbocharger.
The following scope of work is for guidance only:
Disassemble the blanking plates & remove all covers.
Clean out the preservation oil & check the casing, bearings, rotor & nozzle ring.
Apply lubricating oil onto the bearings & mount the rotor and nozzle ring according to the instruction manual.
Assemble the turbocharger casings & silencer according to the instruction manual.
Assemble the turbocharger gas inlet pipe.
Reconnect the lubricating oil inlet.
Follow the starting up instructions in the turbocharger & engine instruction manual.
16. Starting the main engine after the laying-up period
Uninstall the dehumidifier. Remove the dehumidifying vapour powder from the main starting air pipe.
Clean the outside of the engine.
Prior starting the main engine, clean out any rust preservation oil deposits in the scavenge boxes, scavenge air receiver & the piston crowns.
Clean the top of the piston crowns. Check carefully that any preservation oil residuals are removed from the piston crown tops prior starting the engine
Clean, inspect, & pressure test the fuel valves. Inspect the fuel pumps.
Remove the steel blanking plates from the exhaust gas receiver outlet & turbocharger gas outlet to funnel.
Reassemble the turbocharger according to the instruction manual.
Remove the cover from the top of the funnel.
Verification of correct function of engine safety systems (shut down/slow down) must be carried out prior to the first start. For MC/MC-C engines, it is recommend that the first start is performed from the local engine side manoeuvring console. For ME/ME-C/ME-B engines, it is recommended to perform the first start from the control room control, since the local operation panel is also electronically operated.
We emphasise the importance of supplying control air to the exhaust valves in due time prior to first start in order to force out the preservation oil from the air spring chambers (see part 6.5 Exhaust valve).
All items in the “laying-up check list” (as mentioned in paragraph 1) must be brought back to normal service condition prior to start of the engine.
Reference is also made to our instruction manual, specially the chapters “Check during standstill periods” and “Preparations for starting”.
17. Starting the auxiliary engines after the laying-up period
Uninstall the dehumidifier.
Clean the outside of the engine.
Remove the Silica gel bag & check the scavenge air receiver.
Check carefully that any preservation oil residuals are removed from the piston crown tops before starting the engine by opening the indicator valves and turn the crankshaft by turning gear minimum one revolution. Then blast the cylinders clean by turning the crankshaft with starter motor.
Clean, inspect, and pressure test the fuel valves. Inspect the fuel pumps.
Remove the steel blanking plate from turbocharger gas outlet to funnel.
Reassemble the turbocharger according to the instruction manual.
Remove the cover from the top of the funnel.
All items in the “laying-up check list” (as mentioned in paragraph 1) must be brought back to normal service condition prior to start of the engine.
Reference is also made to our instruction manual, specially the chapters “Check during standstill periods” & “Preparations for starting”.
