Page 580 - Subyek Teknik Mesin - Forsthoffers Best Practice Handbook for Rotating Machinery by William E Forsthoffer

The Post-Shipment Phase: Installation, Pre-Commissioning, Commissioning and Start-up Best Practices Be st Practice 1 0.10

Best Practice 10.10Practice 10.10Practice 10.10
Best
Best
Perform driver solo runs to confirm that all the phases of Lessons Learned
construction have been completed successfully, and that Failure to completely check out driver operation prior to
the control and protection systems operate properly. plant start-up will result in start-up delays and expose the
These runs will also confirm: plant to lower machine reliability until the first scheduled
Proper functional operation of all auxiliaries turnaround.
Overspeed protection system check In the rush to complete commissioning activities and start plant
)
Accumulator precharge check production, pre-start-up checks are often minimized. Any critical (un-
)
Trip valve manual exercise check spared) machinery reliability issues that are not identified prior to plant
Governor system check operation will expose the plant to corresponding safety, reliability and
)
¼ where applicable revenue losses until they can be corrected (usually during the first plant
turnaround four or five years after start-up).
In addition to ensuring proper operation of the driver and associated
auxiliary systems, the solo runs are an excellent training opportunity for
site personnel. Benchmarks
Awareness of the function and design basis of the various com- This best practice has been used since 1984 to identify and correct
ponents of the driver and support systems by site personnel will result critical machinery driver potential safety and reliability issues prior to
in a greater understanding of condition monitoring requirements and plant start-up to optimize critical machinery train reliability (> 99.7%).
increase driver safety and reliability.

B.P. 10.10. Supporting Material Failure of ‘final driver’ (internal governor component)
Zero speed inputs
- Confirm manual transfer to and from backup governor
Electro-hydraulic governor functional test and ‘emergency override’
procedure outline - Check raise and lower speed controls while in backup
governor mode
Objective: To confirm proper system functional operation prior - Confirm governor shutdown (trip) operation under the
to equipment start-up. following conditions:
Procedure Detail each test requirement. Specifically note Overspeed setting
Format: required functions/set points. Record actual Failure of both main and backup governor controls
functions/set points and all modifications made.
III Corrective action
Note: All testing to be performed without the unit in - Failure to meet any requirement in Section II requires
operation
corrective action and retest
- Specifically note corrective action
I Preparation - Sign off procedure as acceptable to operate
- Confirm all shut down contracts are in the normal
condition
- Confirm all power supplies are on Steam turbine solo run functional test
- Secure necessary test equipment:
Pressure sources (nitrogen bottles) for pressure procedure outline
simulation at transmitters
Frequency generators for simulating speed signals Objective: To confirm acceptable mechanical operation of the
II Test procedure steam turbine, governor system and safety (trip)
- Take required action to put system in ‘run’ mode system
- Open trip and throttle valve only after insuring the main Procedure Detail each test requirement. Specifically note
required test limits (Note: shop test data should be
Format:
steam block valve is closed used to define acceptable limits). Record actual test
- Simulate turbine start, slow roll and any start sequence values using appropriate instrumentation and note all
‘hold’ points up to minimum governor operating point modifications made.
- Confirm proper operation of ‘raise’ and ‘lower’ speed
buttons I Preparation
- Connect external process signal inputs (one at a time) - Confirm all auxiliary system tests are complete
and confirm proper governor action to input signal (governor, lube system, etc.)
variation - Confirm all inlet steam lines have been cleaned and
- Check overspeed override feature signed off
- Confirm automatic transfer to and from backup governor - Confirm all installed instrumentation is calibrated
‘position control’ for each of the following cases: - Secure all required instruments:
Loss of main governor power supply Calibrated pressure and temperature gauges
Zero external input signal Oscilloscope(s)

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