Where deaerating heaters are net employed, it is recommended that the temperature of the feed_water be not less 120 degrees Fahrenheit to avoid the possibility of setting up localized stress. Where deaerating heaters are employed, it is recommended that the minimum feedwater temperature be not less than 215 degrees Fahrenheit so that dissolved gases may be thoroughly released.
229 Neb. Admin. Code, ch. 21, § 021