Wartsila RT-flex50-D - Possible Causes

Maintenance
2708−2/A1
RT-flex50-D
Wärtsilä Switzerland Ltd
3/ 3
4. Tensioning
Using a feeler gauge, check whether nuts 2 re
st
without clearance.
⇒ Mark position of nuts to seating surface with
a
felt tipped pen.
⇒ Screw pre-tensioning jacks 94252 onto cyli
n-
der cover studs 1 as mentioned in section
2,
however, do not turn back them.
⇒ Connect pre-tensioning jacks to hydraul
ic
unit 94942 and actuate the latter.
⇒ Close vent screws 3 on the pre-tensionin
g
jacks as soon as oil flows bubble-free.
⇒ Slowly raise the pressure to 1500 bar an
d
keep it constant.
Pistons 4 of the pre-tensioning jacks must neve
r
exceed the red limiting grooves ’BN’.
⇒ Tighten nuts 2 with round bar ’RS’.
Check seating of the nuts with a feeler gaug
e
through slot ’KO’.
⇒ Release pressure to ’0’ and remove all pr
e-
tensioning jacks.
Ascertain that these have been turned by abou
t
the same angle of 255_.
CHECK
CHECK
CHECK
C
R
S
K
O
012.964/05
4
BN
7
2
D Where it is found that a nut can be turned considerably less than the others, it
must be assumed that the respective cylinder cover stud has become insuffi-
ciently tensioned.
Possible causes:
− Sealing rings 7 defective (Fig. ’C’).
− Piston 4 jams.
− Junctions of HP hoses leaky.
D To remedy the cause, loosen all cylinder cover studs and then repeat the ten-
sioning procedure.
⇒ Release pressure to ’0’ and remove all pre-tensioning jacks.
Verify that all nuts have been turned equally by an angle of about 255_.
Loosening and Tensioning of Cylinder Cover Waisted Studs
2010
CHECK