a) Deaerator storage volume should be not less than the volume of
feedwater equivalent to 10 minutes of feedwater flow at full turbine load.
b) The deaerator is usually located at the same elevation as the
boiler main upper drum.
Rated Capacity. The rated capacity of a deaerator is the quantity of
deaerated water in pounds per hour delivered to the boiler feed pumps by the deaerating
unit and includes all of the steam used for heating in the deaerator.
Oxygen Removal. Deaerators should be specified to provide condensate
effluent, at all loads, at saturation temperature corresponding to deaerator pressure
and with an oxygen content not to exceed 0.005cc of oxygen per liter of condensate.
Boiler Feed Pumps. For design and other data relative to boiler feed pumps
and feedwater pumping systems, see Section 4, Table 6, and MIL-HDBK-1003/6.
A pressure reducing and
Pressure Reducing and Desuperheating Stations.
desuperheating station is shown in Figure 34.
Typical use of pressure reducing control valves
Pressure Reducing Stations.
are as follows:
a) Boiler drum steam supply to auxiliary steam system supplying
building heating equipment, fuel oil heaters, and deaerator standby steam supply.
Main steam supplemental and standby supply to export
Main steam supply to steam jet air ejector, if used.
For load variations of 3:1 and larger, use two parallel pressure
reducing stations with a common valved bypass; use one for one-third of total load and
the other for two-thirds load instead of single pressure reducing valve, or station.