No oxygen is entering the boiler with the feed water when hydrazine is present in the water ( This will help to decrease oxygen on HP, LP boiler )
 

The objective is to maintain a hydrazine residual between 0.05-0.2 ppm depending on operating pressure and boiler designe. Actual consumption is determined under operating conditions.  A normal dosage is approximately 1 ltr. per day, depending of system layout.

Hydrazine is a convenient reductant because the by-products are typically nitrogen gas and water. Thus, it is used as an ANTIOXIDANT, an oxygen scavenger, and a corrosion inhibitor in water boilers and heating systems. 

Hydrazine is mainly used as a foaming agent in preparing polymer foams. 

No oxygen is entering the boiler with the feed water when hydrazine is present in the water.

Product Technical bulletin

Technical Data Sheet

molecular formula:	H2NNH2
CAS No.:	000302012
molecular weight:	32.05
description:	colorless, oily liquid, fuming in air.
odor:	penetrating odor resembling that of ammonia
density:	1.0036 (25/4°C)
Boiling point:	113.5°C (at 760 mm Hg)
Freezing point:	1.4 - 1.5°C
explosive limits:	4.7 - 100% by volume in air
flash point:	38 - 52°C (open cup)
saturation concentration:	18900 ppm
conversion factors:	1 ppm = 1.31 mg/m3
(at 760 mm and 25°C)	1 mg/m3 = 0.76 ppm
solubility:	soluble in water, ethanol, and isobutanol; insoluble in chloroform and ether
vapor density:	1.04 (air = 1)
vapor pressure:	14.4 mm Hg at 25°C

Product label Hydrazine is a convenient reductant because the by-products are typically nitrogen gas and water. Thus, it is used as an ANTIOXIDANT, an oxygen scavenger, and a corrosion inhibitor in water boilers and heating systems. Hydrazine is mainly used as a foaming agent in preparing polymer foams. No oxygen is entering the boiler with the feed water when hydrazine is present in the water.