A-A-59503C

Abstract

This commercial item description (CID) covers two types of nitrogen: gaseous and liquid. Each type of nitrogen can be obtained in three different technical grades based primarily on nitrogen purity and oxygen content. Liquid nitrogen is used as a cooling agent for low temperature and cryogenic processes to shield temperature-sensitive materials and equipment from the effects of heat. Gaseous nitrogen is used to purge or pressurize systems or provide inert atmospheres. The list of intended uses includes, but is not limited to: pressurizing fuel tanks, hydraulic system accumulators, aircraft struts, rocket engine propellant systems, and carbon dioxide cylinders; purging aircraft oxygen converters; and purging and calibrating instruments. Since some systems are sensitive to oil contamination, gaseous nitrogen is divided into two classes: oil free and oil tolerant. Class 1, oil free nitrogen, is used for applications that cannot tolerate hydrocarbons, such as the purging of oxygen equipment. Class 2, oil tolerant nitrogen, is used for pressurizing oil-containing systems such as aircraft struts.<b><u>Intended Use:</u></b> Oil tolerant nitrogen gas, class 2, is not to be used to purge or pressurize oxygen or air for human respiration systems. It shall only be used with oil-containing systems or systems that can tolerate hydrocarbon contamination, like pressuring aircraft struts. Contamination of an oxygen system with an oil tolerant gas could result in a fire or explosion with loss of life or loss of a complete weapons system. This CID is not suitable for procurement of nitrogen for use in reactor plant, steam plant, and shipyard applications. For these applications see A-A-59155.<br>