Wartsila RT-flex50-D - Loosening of Waisted Studs

Maintenance2751−1/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
94934a94942
94252
94934
g
94935
94935
94934
2
2010
Removal and Fitting of Exhaust Valve, Replacing of Waisted Studs