Gas & Steam Turbine Internal Alignment Methods COMPARISON
Comparing gas and steam turbines internal alignment methods involves assessing various factors to determine which one is recommended or suit better for a particular application.
Here you can find a comparison of different methods and considerations for comparing gas and steam turbines internal alignment:
3D Laser ALIGNMENT : LASER TRACKER TOPS ON / TOPS OFF
GAS TURBINE
STEAM TURBINE
PROS
✔ True internal alignment position for both horizontal, vertical and axial position off all components.
✔ All movements can be made and checked without removing the top.
✔ Laser Tracker can be moved throughout the measurement process to collect data from different view points.
✔ No bracketing needed.
✔ Collects out-of-roundness and internal alignment data at the same time.
✔ Reference points are incorporated to ensure accurate data collection.
✔ Readings can be completed in as little as 1.5 hours.
CONS
➖ Bore presets, Rotor sag and bearing clearance must be added into readings.
robust & flimsy Steam Turbine
PROS
✔ True internal alignment position for both horizontal, vertical and axial position of all components.
✔ All movements can be made and checked without removing the top.
✔ Laser Tracker can be moved throughout the measurement process to collect data from different view points.
✔ No bracketing needed.
✔ Collects out-of-roundness and internal alignment data at the same time.
✔ Reference points are incorporated to ensure accurate data collection.
✔ Readings can be completed in as little as 1.5 hours.
CONS
➖ Bore presets, Rotor sag and bearing clearance must be added into readings.
➖ Top of turbine case must be placed on.
2D ALIGNMENT SYSTEMS TOPS ON / TOPS OFF
GAS TURBINE
STEAM TURBINE
PROS
✔ True internal alignment position for both horizontal and vertical position off all components
✔ All movements can be made and checked without removing the top.
✔ Reference laser can be rechecked easily to ensure accurate readings.
CONS
➖ All initial readings must be recorded in one measurement set.
➖ Bore presets, Rotor sag and bearing clearance must be added into readings.
robust & flimsy Steam Turbine
PROS
✔ True internal alignment position for both horizontal, vertical and axial position of all components.
✔ Reference laser can be rechecked easily to ensure accurate readings.
✔ All moves are made and checked with the Top Off.
✔ Work continues on Turbine deck during the alignment process.
CONS
➖ Bore presets, Rotor sag and bearing clearance must be added into readings.
➖ Top of turbine case must be placed on.
LEAD WIRE
GAS TURBINE
STEAM TURBINE
PROS
✔ Easy to setup.
✔ Easy to interpret.
✔ No additional math needed.
CONS
➖ Can show erroneous values for vertical position if the wire was pinched or crushed at any point during setup.
➖ Only shows vertical position not horizontal.
➖ Turbine has to be un-stacked and stacked to confirm each move.
robust & flimsy Steam Turbine
PROS
✔ Easy to setup.
✔ Easy to interpret.
✔ No additional math needed.
CONS
➖ Can show erroneous values for vertical position if the wire was pinched or crushed at any point during setup.
➖ Only shows vertical position not horizontal.
➖ Turbine has to be un-stacked and stacked to confirm each move.
➖ Work stops on Turbine deck during the alignment process.
OPTICAL
GAS TURBINE
STEAM TURBINE
PROS
✔ True internal alignment position for both horizontal and vertical position off all components.
✔ All movements can be made and checked without removing the top.
CONS
➖ Difficult to setup targets correctly.
➖ Targets are recorded by looking through a scope.
➖ No out of roundness is recorded.
➖ Bore presets, Rotor sag and bearing clearance must be added into readings.
robust & flimsy Steam Turbine
PROS
✔ True internal alignment position for both horizontal and vertical position of all components.
CONS
➖ Difficult to setup targets correctly.
➖ Targets are recorded by looking through a scope.
➖ No out of roundness is recorded.
➖ Bore presets, Rotor sag and bearing clearance must be added into readings.
➖ Work stops on Turbine deck during the alignment process.
EXPRESS ALIGNMENT
GAS TURBINE
STEAM TURBINE
PROS
N/A
CONS
N/A
robust Steam Turbine
PROS
✔ Top of the turbine is never placed back on for internal alignment readings.
✔ All moves are made and checked with the Top Off.
✔ Work continues on Turbine deck during the alignment process.
CONS
➖ As found internal alignment readings should be recorded.
➖ Bore presets, rotor sag and bearing clearance must be added into readings.
FLIMSY Steam Turbine
PROS
Same as Robust Steam Turbine.
CONS
➖ Shell distortion can provide erroneous theoretical tops on position.
➖ As found internal alignment readings should be recorded.
➖ Bore presets, rotor sag and bearing clearance must be added into readings.
Contact ACQUIP SERVICES:
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Publisher: ACQUIP
GAS TURBINE INTERNAL ALIGNMENT Process
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