MAK M 20 - Page 68

Inlet and Exhaust Valve Cones
Inspection / Disassembly and reassembly
A5.05. 01.07.01.01
15000, 7500
M20
en / 31.05.2010 IB021215 1/2
01
See also: 01.02.01.nn, 01.05.01.nn, 01.06.01.nn, 01.08.01.nn
Spare parts list: B1.05.01.2.2107
Time requirement: 1 Pers./ 0,50 h
Personnel qualification: skilled engine hand
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Operating medium: Heavy fuel
Inspection:
of inlet and exhaust valves of one cylinder after 7,500 h
Check contact reflections of the valves and coating.
Maintenance:
of all inlet and exhaust valves after 15,000 h
Tools:
Valve spring compressor W1 2.9222-A
Sequence of operations: (Fig. 1)
1. Disassembly
1.1 Remove cylinder head (01.06.01.nn).
1.2 Remove the valve rocker (01.02.01.nn)
and lift off valve bridge.
1.3 Place the valve spring compressor (W1)
onto the spring plate (2).
1.4 Compress the valve springs (3) and
remove the clamping cone halves (4).
Expand valve springs (3) carefully.
NOTE
The overhaul intervals of the valves depend on the fuel grade used, the operating
conditions of the plant and the quality of the reconditioned valves and seats. They
are therefore different for each plant.
For this reason, the operator must fix the maintenance intervals according to the con-
dition of valves inspected. With any removal of valves, check seat geometry and re-
cut if necessary (01.08.01.nn, 01.08.02.nn.).
WARNING
Spring tension