Explain the lines to atomizing station
From header 1 and 3- 2 isolating valves - combine - then PI and TI- inlet valves - strainer - PIC- NRV - Outlet - Top line has a PSV that pops at 1548 kpa - Another outlet line- PSL at 500 kpa that gives an alarm at the control room- PI - thermocouple- sectionlizing valves for phase 1 and 2 which allows for shutdown- then 2 lines - 1 goes to main and solenoid of every boiler- to purging and atomizing
Explain the utility air supply
Has an inlet- strainer- solenoid- nrv- outlet that then continues to sectionalizing
What is the temperature of the steam?
365 degrees
What is the temperature of the steam?
365 degrees
What do the safety valves lift at, and where is it?
1548 kpa on the atomising steam station
Standby and Commissioning
- The main isolating valves from hp headers 1 and 3 are open
- Steam traps are in commission (isolating open and bypass closed)
- Atomizing main inlet valve is open
- Pressure gauge inlet valve is open
- The control valves inlet and outlet valves open
- Atomizing main outlet valve is open
- Controller set point is 1400 kpa
- SPC opens the steam solenoid valve
Normal running checks
- Main steam pressure before control valve is 4150 kpa
- Both steam pressure controllers are in service (PIC)
- Steam pressure is 1400 kpa
- Hand isolating valve to supply headers are open at all times
- No steam leaks
- Steam traps in commission
Shutdown and isolation
- Cant isolate when burners in commission- will trip them
- Solenoid closed by SPC
- Close atomizing steam isolating valve header 1 and 3
- Close atomizing main station isolation valve
- Close all steam trap isolating and bypass valves
- Atomizing steam pressure gauge is zero
- Ensure all phase hand isolating valves are open if whole plant is isolated
Emergencies
- Safety valve will pop at 1548 kpa
- Serious steam leak
- Low steam pressure
What is the effect of low steam on the system ?
The burners will trip
Corrective actions for low steam, steam leak, over pressure ?
- Set point of pressure controller is 1400 kpa
- Decrease steam pressure to 1200 kpa and when safety valve resets increase slowly to 1400 kpa
- Confirm steam leak and isolate the leak
- Main steam pressure is 4150 kpa
What will the psl do ?
- Sound an alarm at 500 kpa
Where are the vent valves ?
- After atomizing towards the burners
Where is the Temperature element ?
- After atomizing station
Where are the NRV’s ?
- After pressure control valve before outlet
- After solenoid before outlet
Which side is HP header 1 and 3?
Header 1 is on the left and header 3 is on the right facing the control room
