1 reply to this topic

[Rahimzadeh]

Hi dear fellow
Any one can tell me best type of pump can be used as boiler feed water pump in low pressure water tube boiler?
best regards

[kkala]

Horizontal centrifugal pumps (of stages as needed) have been used for boiler installations (capacity 130% of nominal steam production). Points of special care can be as follows.
1. Such a pump takes suction from deaerator drum, so NPSHa is critical. A margin of 2-3 m over NPSHr has been applied by lifting the deaerator (to account for sudden flow variations etc). Drive should not have a rotational speed higher than 1500-1800 rpm. Double suction pumps were not used in mentioned cases.
2. Automatic min flow return should be mechanical (e.g. type yarway or equivalent, not electronic) for better safety ; it should return to deaerator drum.
3. Two pumps to be installed, one operating the other in hot standby.

Above principles have been applied for steam boilers in refinery service. API 610 was preferable, yet not mandatory.

Edited by kkala, 28 December 2010 - 10:16 AM.