7
Operation and Maintenance
Diffuser Reassembly:
After removing the diffuser for inspection, checks should be made to ensure that:
1. The diffuser/body gasket is new and that the seating surfaces are clean
2. Before inserting and locking the bolts, ensure that the diffuser male/female pilots are inserted properly
(see drawing for torque values)
3. The diffuser throat bore is concentric to the nozzle bore
4. There is no debris or any other form of obstruction within the diffuser that may prevent free passage of steam
Reassembly Procedures
If it is found necessary to disassemble the thermocompressor for inspection, parts replacement, or for any other reason, care must be
exercised during the reassembly process.
Nozzle Reassembly:
1. After removing the nozzle for inspection or replacement, checks should be made to the assembly to ensure:
2. The nozzle/body gasket is new and that the seating surfaces are clean
3. The nozzle is repositioned with numbers visible through suction flange
4. Blue Loctite used on nozzle retaining screws (see drawing for torque values)
5. The nozzle seat is sealed to prevent leakage of the high-pressure steam into the low- pressure section of the body
6. There is no debris or any other form of obstruction within the nozzle that may prevent the free passage of steam
Spindle and Bonnet Reassembly:
After removing the spindle for inspection, carry out checks to ensure that:
1. Any damaged soft parts of the packing guide are removed and discarded
2. Remove and discard the soft parts of the packing if the spindle threads have been pulled through them
3. The packing guide (reference drawing A50270) is in good condition, if the packing guide is in good condition, reassemble it
and place it back into the bonnet
4. The spindle guide (13) is clean and in good condition. If removed or replaced, reassemble the bonnet with locking
compound, and tape the flats down to pin. (See notes on drawings for your understanding)
5. Inspect areas of the spindle that guides ride is clean and in good condition and insert the spindle (12) through the bonnet
and both guides
6. Slide the packing (2) on drawing A50270 carefully over the spindle threads and install it in the bonnet (5).
7. The bonnet/body gasket (4) is new, and the seating surfaces are clean.
8. The packing follower and packing flange are clean and in good condition, slide the flange and follower over spindle threads.
9. Install nuts (18) on studs (17) in bonnet and tighten to 20 ft-lbs torque. Do not over tighten as it can cause drag on the
spindle. Check packing after the unit is started up, if packing leaks tighten nuts in 1/4 turn increments until it stops.
Actuator and Positioner Reassembly:
1. A product bulletin for the actuator and positioner are available on fisher.com
2. Put the thin nut on the spindle then the bigger one, and then the travel indicator. Run all the way down
3. Align the actuator to the body and hammer the big locknut tight with Blue Loctite
4. Line up the top white line on the travel indicator with the middle line on the black magnet
Before the thermocompressor is put back in service, it is advisable to stroke test the spindle/actuator assembly to ensure
that the spindle is not coming into shock contact with the nozzle or that the packing follower was not over-tightened
causing the spindle to get chatter, lag, or stick.
General Precautions
1. It is inadvisable to attempt to use this thermocompressor for any other duties other than those for which
it has been designed
2. It is dangerous to use the shut off device fitted to this thermocompressor as a stop valve. It is not intended nor designed for
leak free closure. Its only purpose is to arrest the flow of high-pressure steam for a very short period, during air failure or
plant shut down, to enable the main steam isolating valve to be closed
3. In the event of air failure or plant shut-down, do not rely on the shut-off device fitted to this thermocompressor to give
complete sealing of the high-pressure steam
4. A block valve should never be installed on the discharge piping of the thermocompressor
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