Feedwater System Flashcards
At What flow does the SUBFP recirculation valve close? OPEN?
Opens at 400 KPPH
Closes at 664 KPPH
- What boiler pressure is recommended before swapping from the SUBFP to the MBFP?
1500-1800 psi
- List the permissives to start the SUBFP? MBFP?
SUBFP Breaker racked in S/R in run Suction, discharge, and recirc valves open Aux and coupling oil pumps running Low suction lockout reset Fluid drive at min and in manual Normal DA level Top and bottom barrel temp within 40 deg
MBFP
Suction, discharge, and recirc valves open
Vapor extractor on
Normal oil level
One A/C oil pump I/S, backup AC and DC oil pumps in auto
Top and bottom pump barrel temps within 40 deg
Vibration trips enabled
BFPT seal temp control station in auto with set point at 300 deg
BFP control station at min, 1500 psi on boiler
- What do the upper and lower pump barrel temperatures have to be within before you can start the MBFP or SUBFP?
40 degrees
- Explain in detail the steps that happen when you latch the MBFP for start-up.
When you latch the MBFP go to the BFPT master page, click on latch button, trip block will be enabled, HP and LP stop valves will drive open. In the event the stop valves fail to open. You can push red button between the two valve indication lights and manually open stop valves. This will enable the MBFP control station with the “RAMP” indication.
- Explain how to swap from the SUBFP to the MBFP
- Have operator check out MBFP
- Select BFPT page, start vapor extractor, ensure normal oil level in reservoir, ensure 1 AC oil pump is I/S, and backup AC and DC oil pumps are in auto
- Have shift supervisor enable vibration trips
- Pull up MBFP graphic
- Ensure top and bottom barrels are within 40 deg
- Ensure suction, discharge, and recirc valves are open
- MBFP is at min with at least 1400 PSI on boiler
- On BFPT page click the latch button, open HP and LP Stop valves then the supply block valves
- Pull up the drum level page and click the TBFP Ramp button (an overlay will appear) then click the red button-the turbine will roll off and go to 1200 RPM for a 20 min heat soak (continue to monitor graphic for heat and vibration)
- When heat soak is complete you will get an alarm. Click the red button again and the turbine will ramp to 3000 RPM
- Increase flow on the MBFP control station until it matches the SUBFP flow 12. Place the MBFP in auto and the SUBFP in manual and ensure the MBFP picks up flow
- Once the MBFP is controlling you need to Lower the SUBF to min. then trip the SBFP (discharge will close which will close the check valve & will then reopen)
- Place SUBFP back in auto
- In the event that you lose the MBFP, What are some steps that you can take in order to save the unit?
Ensure the SUBFP starts and bring up the speed while watching drum level
Start dropping load and pressure so SUBFP will contribute to Drum
Remove 2 levels of coal (A & E)
Take the unit to Turbine Follow and start dumping pressure so the SUBFP can maintain drum level
- What must you do to the boiler so that the SUBFP will contribute flow after losing the MBFP?
Drop pressure down to 1400-1800psi or until SUBFP can maintain drum level and drop load.
- In what order should the low pressure and high pressure heaters be put in service?
Low pressure to high pressure (8-7-6-5-4-3-2-1)
- Describe the procedure to test the extraction line block valves and non-return valves? What are you watching for?
Select specific feed water heater screen. To perform test depress green arrow on the extraction block valve control station until the piston turns green and shows travel. Release the green arrow once travel is noticed on piston.
High pressure heaters - have to be driven open with arrow.
Low pressure heaters - will travel open once the green arrow is released.
Watch to ensure the extraction block and non-return valves are operating and ensure the drain valve operation.
- How long does it take to gravity fill the boiler from the DA?
Approximately 3 hours
- How long does it take to fill the boiler using the SUBFP?
Approximately 1.5 hours
