Wartsila RT-flex50-D User Manual

Maintenance
3425−1/A1
RT-flex50-D
Wärtsilä Switzerland Ltd
3/ 4
3.2.3 Reuse of piston ring
Pull one piston after approx. 2000 operating hours, to establish the wear rate of the
cylinder liner and the piston rings.
With the aid of the diagram in Clearance Table 0330−1 ’Piston and piston rings’ the
approximate service life of a piston ring can be estimated.
At the same time the replacement date for the piston ring can be estimated.
3.4 Examples (see also the diagram)
Case one New cylinder liner, new piston rings:
− Piston pulled after 2000 operating hours.
Wear was established as:
− Cylinder liner 0.14 mm = 0.07 mm / 1000 h point 1
− Piston ring 1.00 mm = 0.50 mm / 1000 h point 1
D If all piston rings are otherwise in good condition they can be refitted. Howev-
er, consider that refitted piston rings may only be used till limiting line I min.
Case two First piston overhaul after total 7000 operating hours:
− Total wear of cylinder liner 0.49 mm = 0.07 mm / 1000 h point 2
− Total wear of piston ring 3.50 mm = 0.50 mm / 1000 h point 2
D Point 2 lies between line I min and I min N, therefore piston ring must be re-
placed by a new one.
The new piston ring comes to lie at point 3.
Case three Second piston overhaul after total 13 000 operating hours of the engine:
− Wear of cylinder liner 0.42 mm since first overhaul = 0.07 mm / 1000 h point 4
− Wear of piston ring 3.00 mm since first overhaul = 0.50 mm / 1000 h point 4
D Point 4 lies between line I min and I min N, i.e. piston ring can not be reused.
500 501 502 503 504 [mm]
16
15
14
13
12
1
2
3
4
0
l
min
l
min N
3
2
1
4
RADIAL RING WEAR [mm]
ORIGINAL PISTON RING WIDTH = 16.50 mm
MAX. CYLINDER LINER WEAR = 503.50 mm
PISTON RING WIDTH l [mm]
Line I min = for old reused piston rings
Line I min N = for new piston rings
D Note down whether they are new ones or used ones.
D To ensure good sealing of the whole piston ring set, the diagram must be fol-
lowed without fail. When piston rings are worn too much, an optimum seal of
the piston ring set is no longer ensured.
D Experience has shown that used and refitted piston rings seal rather less well
in operation than newly fitted ones. For this reason the limit for total wear of old
reused piston rings (I min) has been set somewhat higher than for new piston
rings (I min N).
2010
Piston: Checking Piston Ring Wear

Wartsila RT-flex50-D Specifications

General

Brand	Wartsila
Model	RT-flex50-D
Category	Engine
Language	English