Replacing Labyrinth Ring on Turbine Rotor -MAN B&W NA 57 TC

Tools Required

1. Tommy bar
2. Assembling ring

Starting Position

Turbine rotor removed.

SEQUENCE OF OPERATION
Removal

1. Fit assembling ring onto ring nut, paying attention to straight pin.
2. Unscrew ring nut with the use of the tommy bar.
3. Extract labyrinth ring from turbine rotor, if it has become a shring-fit, cautiously turn it down to dimension.
4. Slip on new labyrinth ring and secure it with ring nut.

Installing

1. Hang bearing casing in hoist.
2. Lift bearing casing off the bearing casing stand and cautiously insert it in axial direction over the studs into gas outlet casing.
3. Screw on and tighten all lock nuts, cautiously insert cover disc, using the bolts as a guide.

Note: Before inserting the bearing casing and the cover disc, check to see that the packing as well as the round section seal ring have been refitted, having made sure they are in good condition.

Caution: When inserting the casing, care must be experienced to avoid damaging turbine blades, outer wall of diffuser and shroud ring. Turn rotor by hand  to see it is running freely.

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