leads to the control side of valve M 317 on the main starting valve, to the second connection on valve M 371/1 and to the control console. The main line leads to the starter control gate valves and finally to the starting valves.
With the pressure vessel opened, air is present at the main starting valve, at valve M 317, at valve M 371/1 (if present), at valve M 329/2, in the control device and at valves M 306 and M329/1.
C Control air 8 bar D Control air for operating device Figure 3: Compressed air and starting system (Section 3) Start procedure (Description
section 1)
The starting process is initiated by a signal from the operation or remote control device to the valve M 329/1.
This valve can be used for manually starting the engine in an emergency.
The signal opens the upstream valve of valve assembly M 329/1 assuming that the indexing unit is disengaged, i.e. valve M 306 is set to through-flow (blocking is effected by the electrically actuated valve M 745 in stationary applications). In this case, the valve combination M 329/1 is finally opened.
It releases the route for the air to the control side of valve M 317. The valve switches over. The connections A and E on the main starter valve, which were previously under pressure, and thus held the main cone closed and the bleed valve open, are thus depressurised. This causes the main starter valve to open and the bleed valve to close (see Figure 4). As a result, air flows to the starter valves in the cylinder heads. The booster servomotor (if present) is actuated at the same time.
Main starter valve The valve cone of the main starter valve is closed if the inlet side is depres-surised. As soon as the compressed air line is opened, the pressure acting on the shoulder attempts to open the valve cone. The force of the pressure spring and the pressure at connection A, which is transferred to the annular surface R, counteract this. In this condition, connection E is also under pressure, i.e. the bleed valve is open.
6631 2.4.2-02 EN 3 (8)
Systems
As soon as the control system switches over, valve M 317, connections A and E are depressurised. The main cone is opened, the bleed valve closed by the air pressure building up in the exhaust casing.
1 Inlet housing SV Safety valve 2 Outlet housing Bleed Bleeding
3 Valve cone S Shoulder
4 Compression spring R Annular surface
5 Air bleed valve A-E Connections on the valve (see figure 1) Figure 4: Arrangement/connections to the main starter valve (Example: Engine V40/45)
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Systems Technology V32/40
Figure 5: Main starter valve Start procedure (Description
section 2)
With the valve M 329/1 opened, the starter control gate valves are also under pressure. As soon as the starter cam closes the ram pipe in a cylinder, the distributing slide valve is switched over and pilot air directed to the starting valve. This opens the starting valve and the full flow of air is directed into the combustion chamber. The piston is pressed downwards. The crankshaft and camshaft are turned. The next starter control gate valve is thereby switched over and the next cylinder supplied with air.
Starter air pilot valve In the starter air pilot valve which was previously active, the rotary motion of the camshaft causes the cam to release the back-up pipe. The pilot piston
6631 2.4.2-02 EN 5 (8)
Systems
is thereby pressed back to its starting position and the line to the starting valve vented.
1 Fuel injection pump 6 Starter cams 2 Distributing slide valve 7 Camshaft
3 Housing top section A Control air to the starting valve
4 Starter air pilot valve B Compressed air from valve assembly M 329/1
5 Housing bottom section C Bleeding
Figure 6: Starter air pilot valve - Cross section left/layout right
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Systems Technology V32/40
safe start is guaranteed in all crankshaft positions.
1 Starting valve 7 Housing bottom section 2 Cylinder head 8 Piston/Valve cone 3 Support ring 9 Compression spring 4 Cylinder liner
5 Fuel injection valve A Control air from the starter control gate valve 6 Housing top section B Compressed air from the main starting valve Figure 7: Starting valve - Cross section on the left/Layout on the right
Indicator cocks/Safety valves Indicator cocks for connecting the cylinder pressure measuring devices are directly screwed into the cylinder heads or (with marine main engines) together with spring-loaded safety valves in the pipe lengths connected there.
Indicator cocks/Safety valves Indicator cocks for the connection of cylinder pressure measuring devices are screwed directly into the cylinder heads. Spring-loaded safety valves are also mounted on the cylinder heads in marine engines.
Flame breaker Flame breakers are installed in the connections of the starting air pipe to the support rings of the cylinder liners. They are provided to prevent flames from flashing back if the starting valves are damaged.
Drainage In the connection line from the pressure tanks to the main starting valve a discharge cock must be fitted at the lowest point. This cock must be opened at regular intervals to remove accumulated condensation from the pipes.
The cock is used for bleeding the pipe prior to assembly work. The relief cock is used for the same purpose on the main starting valve, which is fitted to the relief pipe of the air bleed valve.
Bleeding the pipe prior to
assembly work The relief cock must be opened prior to starting maintenance work. This prevents pressure from building up in front of the main starting valve as a result of leaks in the pressure tank shut-off fittings which could lead to the unintentional starting of the engine.
Emergency stop There is an emergency stop device in order to be able to shut down the engine quickly in an emergency. It consists of the valve assembly M 329/2, an air line arranged downstream of the fuel pumps and emergency stop pistons, which act on the control rods of the fuel pumps. When actuating
6631 2.4.2-02 EN 7 (8)
Systems
the device, the upstream valve is opened manually (only in marine applica-tions) or electrically. The second valve is also opened with compressed air, and air flows through the distributor to the switch-off piston of the injection pumps and sets the control rods to zero filling. By means of the articulated lever, the engine can be switched off irrespective of the position of the reg-ulating linkage and the speed regulator.
Slow turn device With the indicator cocks closed, the device permits the engine to turn slowly over for approx. 3 rotations with the objective of ascertaining whether all cylinder areas are free of liquids for the subsequent starting procedure. The device is based on the existing starting system. It operates at a reduced starter air pressure of approx. 12 bar.
For explanations on the symbols and abbreviations used please consult Section 5.
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