CID A-A-59503C涵盖两种类型的氮气:液态和液态 气态的每种类型的氮都可以在两个不同的技术等级中获得，具体取决于 氮纯度和氧含量。液氮被用作低温冷却剂 屏蔽温度敏感材料和设备的温度和低温工艺 来自热的影响。气态氮用于净化或加压系统或提供惰性气体 大气。预期用途清单包括但不限于给油箱加压， 液压系统蓄能器、飞机支柱、火箭发动机推进剂系统和碳 二氧化碳气瓶；清洗飞机氧气转换器；以及清洗和校准仪器。 由于一些系统对油污染敏感，气态氮分为两种 类别:无油和耐油。1类，无油氮气，用于不能 容忍碳氢化合物，如氧气设备的吹扫。2类耐油氮为 用于对飞机支柱等含油系统加压。

CID A-A-59503C covers two types of nitrogen: liquid and gaseous. Each type of nitrogen can be obtained in two different technical grades based 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 use 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 which 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.