WÄRTSILÄ RT-flex50-D, Руководство по обслуживанию

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Maintenance
3403−1/A1
RT-flex50-D
Wärtsilä Switzerland Ltd
3/ 8
3. Tensioning the waisted studs of piston foot fastening
⇒
Clean the threads of waisted studs 3
and the area around nuts 4.
⇒
Apply oil to the threads of the waisted
studs and screw on the nuts.
⇒
Tighten the nuts with round bar ’RS’
by hand.
Using a feeler gauge, check whether the
nuts rest without clearance.
⇒
Mark position of nuts to seating sur-
face with a felt tipped pen (Fig. ’a’).
⇒
Completely screw the pre-tensioning
jacks diagonally onto waisted studs 3
(Fig. ’A’). Moreover, vent screws 5
are to be opened slightly so that pis-
tons 7 can slide back to their initial
position i.e. there is no or very little
clearance at ’x’ (Fig. ’B’).
⇒
Connect both pre-tensioning jacks to
HP oil pump 94931 as shown in Fig.
’A’.
⇒
Shut relief valve ’EV’ and start up HP oil pump
94931 till bubble-free oil flows out through vent
screws 5. Shut the vent screws.
⇒
Slowly raise the pressure to 1500 bar.
Pistons 7 of the pre-tensioning jacks must never exceed
the red limiting grooves ’BN’ (Fig. ’B’).
⇒
Keep the pressure of 1500 bar constant and tighten
nuts 4 with round bar ’RS’ till firmly seated.
⇒
Release pressure to zero with the aid of relief valve
’EV’ at the HP oil pump and then screw the pre-ten-
sioning jacks onto the other two waisted studs.
These are to be tensioned in the same sequence as
described above.
After tensioning the nuts check their seatings with a
feeler gauge through slot ’KO’.
After tensioning the nuts check again if these have been
turned by about the same angle i.e. about 80
_
,
compared with the marks previously made (Fig. ’b’).
CHECK
CHECK
B
x
Fig. ’a’
y
Fig. ’b’
y
009.752/02
x
010.031/02
PRE-TENSIONING JACK PLACED FOR
TENSIONING LOOSENING
TIGHTENING ANGLE
SA
x
8
RS
7
BN
013.254/05
3
4
KO
5
2010
Piston: Removal and Fitting