Boiler feed pumps start up & shutdown procedure

                    

                 Start-up Pre-check lists

• Ensure Boiler feed pump is not in permit for maintenance works
• Ensure all the maintenance activities on pumps are completed
• Ensure equipment are normalized from electrical & mechanical side
• Ensure Boiler feed pump is free from obstacles
• Ensure enough lighting or illumination is available there
• Ensure pump coupling is well guarded by robust coupling guard
• Ensure Pumps local field instruments like pressure gauges, switches, vibration sensors, DP gauges are healthy
• Ensure coupling is free to rotate

Starting procedure:

Start permissive (interlocks)

• Ensure deaerator level is normal
• Ensure feed pumps suction valves is open
• Ensure cooling water line & outlet valves to bearings & mechanical seals are open and also water is circulating through the lines.
• Ensure bearing temperatures are normal
• Ensure bearing vibration showing DCS is zero
• Ensure there is no alarm exists for strainer DP (differential pressure)
• Ensure suction pressure is normal
• Ensure discharge valve of the pump is closed
• Ensure minimum recirculation valve or ARC valve is in open condition
• Ensure balance leak off line valve to deaerator is open (In some valves are not provided to balance leak off line)

Start-up sequence

• Take clearance from electrical & field person to start the pump
• After getting the clearance from both the team, start the pump by giving minimum set point 80% if it is VFD driven.
• Once the pump started, ensure pump will attain minimum 40% RPM in just 10 seconds (in case of journal bearing pumps).For non-journal bearing pumps speed ramp up time is not recommended specifically.
• During speed ramp up check bearing vibrations & temperatures are normal.
• Ensure pressure in the discharge pressure gauge is increasing slowly & has reached rated pressure at rated speed.
• Then check the vibration, bearing temperatures & sound from pump.
• Check & ensure the correctness of balance leak off line pressure
• Wait for stabilization of the pump, once the pump attained rated parameters, check the motor current, temperature & vibrations & ensure they are within permissive limit.

Also recheck pump bearings vibration, temperatures & any abnormal sound from pump.

Pump normal shutdown procedure

• For VFD driven pumps reduce the pump speed to 80% (for start delta driven pumps speed cannot be reduced)
• Close the pump’s discharge valve
• Then stop the pump

Do not’s for Boiler feed pumps

• Do not rotate the pump in reverse direction, reverse direction leads the seize of pump
• Don not run the pump if its suction water temperature is more than design/required
• Do not operate the pump at less than 80<% load for long time to avoid damage to the bearings
• Do not close the auto recirculation line valve
• Do not close the balance leak off line valve (if provided)
• Do not stop the pump with discharge valve open
• Do not throttle the suction valve of the pump at lower load, can throttle discharge valve

 

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