WÄRTSILÄ RT-flex50-D, Maintenance Manual

Page: 198 / 522

Maintenance
2751−1/A1
RT-flex50-D
Wärtsilä Switzerland Ltd
2/ 7
1.1 Loosening of waisted studs
Remark: It is essential that instructions 9403−4 referring to the application of hy-
draulic pre-tensioning jacks to screwed fastenings be strictly followed.
⇒
Clean threads of waisted studs 1 as well as the area around nuts 2 (Fig. ‘B‘).
⇒
Place pre-tensioning jacks 94252 on the two waisted studs (Fig. ’C’) to be
loosened.
⇒
Screw pre-tensioning jacks down at piston 4 using round bar ’RS’ with vent
screw 3 open until there is only little or no clearance at ’x’.
⇒
Screw back pre-tensioning jacks by about
¾
turn (gap ’SA’ in Fig. ’B’).
⇒
Connect pre-tensioning jacks to hydraulic unit 94942 as shown in Fig. ’C’.
⇒
Actuate the hydraulic unit and close the vent screws as soon as oil flows
bubble-free.
⇒
Actuate the hydraulic unit until a pressure of about 1530 bar is indicated.
Pistons 4 of the pre-tensioning jacks must never exceed the red limiting grooves
’BN’ (Fig. ’G’).
⇒
Turn all nuts 2 back by one turn, using round bar ’RS’.
⇒
Release pressure to ’0’ at the hydraulic unit and then remove pre-tensioning
jacks.
B C
013.487/05
013.501/05
3
94252
4
5
RS
1
SA
94934g
94935
94934a 94942
94252
94934g
94935
94935
94934
2
2010
Removal and Fitting of Exhaust Valve, Replacing of Waisted Studs