WinGD WARTSILA RT-flex58T-D, Maintenance Manual

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Maintenance
3425 − 1/A2
RT-flex58T-D
Winterthur Gas & Diesel Ltd.
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3. Measuring piston ring grooves
Check all dimensions and record them (see Clearance Table 0330 − 1 ’Piston and
piston rings’). These records are important for later evaluation of the running gear.
They should encompass all dimensions, the date of overhaul and operating hours
of the various components and of the engine itself.
3.1 Measurement with piston in situ (through scavenge ports)
The measurement of the piston ring clearance has to be carried out at two to four
free positions around the complete circumference of the piston head. The number
of measurement points depends on the accessibility.
Make sure that feeler gauge 94122 is pushed into the piston ring groove until it
touches the inner diameter of the groove, i.e. at point A. If there is a wear step on
the chromium layer, the feeler gauge can be pushed only to that point (C3).
Remark: Also consider the deposits in the piston ring groove and/or on the piston
ring top face.
⇒ Move piston 3 down (C1) by means of the turning gear.
⇒
Make sure that the total clearance is measured:
First measure the clearance ’x1’at point A.
⇒
Afterwards repeat the measurement at the same circumferential position and
measure the clearance ’x2’.
The sum of both values will give the total piston ring clearance.
Remark: The reason for this split measuring principle is that the piston rings might
be in a tilted position and thus not fully pushed-up and tight to the upper face of the
piston ring groove (C2).
The maximum clearance is at point A. For the maximum wear data see Clearance
Table 0330 − 1 ’Piston and Piston Rings’.
If the clearance at point A exceeds the permitted value, the piston rings have to be
replaced and the piston head has to be reconditioned.
For reconditioning of piston crowns please contact your nearest Wärtsilä Service
Center.
C
PISTON MOVED
DOWN (C1)
(C2)
WEAR STEP ON
CHROMIUM LAYER (C3)
1
x1
x2
94122
3
3
1
3
1
1
3
POSSIBLE WEAR
SHAPE ON GROOVE
WCH02244
WCH02244
A
2013-08
Checking Wear of Piston Rings and Ring Grooves with Three Piston Rings
CHECK