1. GENERAL
Operating experience will be the basis for determining the need for a plug-in cartridge removal of the turboexpander. Regularly scheduled maintenance is not required. The following procedures describe plug-in cartridge removal and installation. Numbers in parenthesis () indicate item “reference designators” on the Turbo Assembly Drawing and the respective single level bill of material.
WARNING
If any replacement hardware is used (for example, nuts, bolts, etc.), make certain that it is of equal or better quality than that called out in the bill of material.
The following component weights and their respective center of gravity should be considered before any maintenance procedure.
| Plug-in Cartridge | 1,650 lb | (749 kg) |
| Expander Case | 995 lb | (452 kg) |
| Compressor Case | 1,900 lb | (864 kg) |
| Electric Actuator and Bracket | 120 lb | (55 kg) |
| Total Weight | 4,600 lb | (2090 kg) |
In addition to the following drawings, refer to the ETAC-8RG Turboexpander removal and installation instructions provided later in this section.
- Turboexpander Outline Drawing
- Turbo Assembly Drawing
5-2. ETAC-8RG PLUG-IN CARTRIDGE REMOVAL
NOTE
If any replacement hardware is used (for example, nuts, bolts, etc.), make certain it is of equal or better quality than that called out in the bill of material. Also note that the following pages provide a general guideline only. For more detail, see the Turbo Expander drawing.
WARNING
Do not work on the turbine until it has been defrosted to ambient temperature, isolated, purged, and all compander piping has been fully depressurized. Also make sure that all electrical equipment is de-energized and locked out. ALWAYS follow site safety requirements for lockout/tagout.
| 1 | Isolate the turboexpander from the process and defrost. Close the appropriate process block valves as outlined in the plant operating manual. Follow all safety procedures to ensure that valves will not be opened accidentally. Remember that seal gas entering the machine can pressurize piping up to the block valves. |
| 2 | Disconnect the oil, seal gas, instrument lines, and conduit. Remove the nozzle actuator assembly. Plug, tape, or otherwise seal the disconnected lines and openings in the bearing case to keep out dirt.
CAUTION Protect all machined surfaces and flange connections from damage. The smallest scratch can create a leak path. |
| 3 | Remove the compressor shroud (19) as follows. First, install three alignment studs to support the weight of the shroud. This is done to prevent damage to any of the seal teeth while removing the shroud. Then carefully slide the shroud off over the alignment studs. |
| 4 | Support the weight of the compressor housing (13) with a hoist, then remove the nuts (35, 37) attaching the compressor housing to the bearing case. It may be necessary to use jacking screws in the compressor case housing to free the two cases. Pull the compressor housing away from the bearing case until it is clear of the
compressor wheel. Set the compressor housing aside and cover the machined surfaces to prevent damage. |
| 5 | Unbolt the bearing case (12) from the turboexpander pedestal and remove the bolts from the oil drain flange on the bottom of the bearing case. |
| 6 | Remove the nuts (35) attaching the bearing case to the expander case (11). Using the jacking screw holes in the bearing case, break the two cases free from one
another. Connect a hoist to the bearing case, then slide the bearing case out of the expander case until the expander shroud (17) clears the expander case. The plug-in unit can now be hoisted away. |
| 7 | The plug-in cartridge may be disassembled further or crated for return to the Air
Products CryoMachinery Production Facility. CAUTION The box used for shipping the plug-in cartridge must be rigid, and the plug-in cartridge must be bolted or secured to the base. Damage to the plug-in cartridge may result if these instructions are not followed. |
3. ETAC-8RG PLUG-IN CARTRIDGE INSTALLATION
| 1 | Inspect and clean the expander case (11) to remove moisture that may have condensed while the expander case was open to atmosphere.
CAUTION It is especially important that the expander inlet and volute are clean and dry. If water is blown through the expander at startup, the expander nozzle assembly may freeze, making it inoperable. |
| 2 | Visually inspect the expander discharge diffuser/insulator (16, 24). The diffuser should be tight within the expander case. If not, remove and inspect. |
| 3 | Remove the compressor shroud (19) from the compressor housing (if not already done per 5-2-3). |
| 4 | Make sure the compressor case O-ring (65) is in place on the compressor case and is in good condition. A new O-ring is supplied with each plug-in. |
| 5 | Position the compressor housing against the bearing case, and secure it with the nuts and bolts. |
| 6 | Install compressor shroud (19) using alignment studs to guide into place.
NOTE Torque values for all critical assembly bolts or studs are listed on the Turbo Assembly drawing. Be certain to follow these recommended values during the entire installation. |
| 7 | Make sure the expander case O-ring (68) is in place and in good condition.
CAUTION DO NOT coat any of the Omniseals in gas service with grease or lubricant. The Omniseal has a Teflon cover that must remain dry at assembly to ensure that it will seal in operation. All O-rings should be lightly coated with process-compatible O-ring grease. |
| 8 | Using a hoist, carefully guide the plug-in cartridge into the expander case and secure it with the bolts and nuts.
NOTE After installing expander case (11) onto plug-in unit, or plug-in unit into plant, turn rotor by hand. If rotor does not turn, the expander shroud must have cocked during case or plug-in installation. Back off expander case until rotor turns by hand, then re-torque nuts. |
| 9 | Bolt the bearing case to the pedestal, and reconnect the oil drain piping. Remove any blanks located in the oil drain line. |
| 10 | Reinstall the speed probe. Use pipe sealant on the probe threads to prevent oil leakage. The probe looks at six holes on the circumference of the shaft. Before installing the probe, look into the hole to be certain that the probe is not installed over a hole. Then screw the probe in by hand until it just touches the shaft. DO NOT APPLY ANY FORCE WITH ANY TOOLS. Then back the probe out one full turn (1.4 mm [0.055″]) and lock it in position with the jamnut. |
| 11 | Reinstall the vibration probe in the same manner as the speed probe. Be careful not to damage the tip of the probe when screwing it into the bearing case. Check to determine that the gap voltage is between –6 and –7 volts. Adjust probe to obtain the proper gap voltage if necessary. |
| 12 | Reconnect the oil, seal gas, instrument lines, and conduit. |