Type .005 DA-IST atmospheric deaerators are recommended for high-pressure boiler applications. Unit equipped with internal spray-tray design. The standard .005 design removes dissolved oxygen to a maximum level of .005 cubic centimeters per liter of feed water. The atmospheric deaerator design provides unrestricted venting of the non-condensing gases, allows for gravity returns, and generally produces less steam loss under partial load conditions than a pressurized deaerator. Unit designed so that undeaerated water only comes in contact with stainless steel to prolong life of unit.
The amount of hot condensate returns influences which design is most appropriate for applications. A single-tank design (DA-IST) is typically used on systems having 80% or more make-up water. A two-tank design (DA-IST-2T) that includes a standalone surge tank is typically used on systems having more than 20% return hot condensate.
Standard deaerator receivers available in black steel. For two-tank designs, the surge tank can be either plasite-lined or made 300 series stainless steel. Unit can be built to handle a wide range of flows and pressures; receiver can be customized in terms of diameter, length and height to meet job specific requirements.
Number of pumps on unit depends upon number of boilers to be supported and stand-by specifications. Pump motors can be either 1750 RPM or 3500 RPM, single or three phase. Unit equipped with single stage or multi-stage pumps depending upon operating conditions. Pumps bronze-fitted with industry standard motors and mechanical seals rated for temperatures up to 300°F. Higher temperature seals and special faces available upon request. Pumps can be mounted in either a vertical or horizontal orientation.
Deaerators equipped with direct steam injection assembly with stainless steel preheat tube; assembly includes temperature regulator that can be either pneumatic controlled or self-contained. Other accessories include but not limited to gauge glass assembly thermometer, inlet strainer, butterfly isolation valve, low-water cut-off or alarm switch, electrical control panels and tank insulation.