Page 392 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

TURBINE CASlNQ CARBON RlNQ

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HAFT

Fiiure 87. Packing case arrangement, including carbon rings.

pose and moderate pressure machines, one is a paste which is spread on
the joints, the other is a plastic string type sealant.
A combination of 1/s inch (3 mm) diameter string sealant and paste
compound is used to seal the vertical joints between the packing cases
and turbine casing on some models, and the joint between the outside
radius of the packing cases and casing on turbines executed as shown in
Figure 8-7. A combination of 1/16 in. (1.6 mm) diameter plastic string
sealant, placed on a layer of paste compound is used to seal the following
steam joints:

1. Steam chest body (1, Figure 8-4) to the turbine casing.
2. Governor valve cover (21,35) to the steam chest body (1, Figure 8-4).
3. Trip valve cover (3) to the steam chest body (1).
4. Nozzle ring (33, Figure 8-5) to turbine casing.
5. The horizontal and vertical turbine casing joints. (Figure 8-8).

Screw threads subjected to high temperatures often gall during disas-
sembly. It is recommended that anti-galling compound be applied to the
threads of all studs, bolts, socket head cap screws, and other threads sub-
jected to high temperatures.