Instrument nitrogen and instrument air

In the instrumentation system of coke ovens, instrument air is typically used to operate devices such as valves, pneumatic actuators, and controllers. Nitrogen is used in situations where it is necessary to avoid corrosion or the risk of combustion caused by oxygen, such as in high-temperature or flammable environments. ### Differences between instrument air and nitrogen – **Instrument air**: It is primarily compressed and purified air, used mainly in general pneumatic equipment and control systems. It contains oxygen, which can support combustion. - **Instrument nitrogen**: It is a high-purity form of nitrogen that contains no oxygen, and it is primarily used in situations where prevention of oxidation and combustion is necessary. Nitrogen is inert; it does not support combustion nor reacts easily with other substances. ### Consequences of using instrument nitrogen instead of instrument air: 1. **Safety risks**: Since nitrogen is an inert gas, its use in inappropriate environments (such as ordinary pneumatic equipment) may result in insufficient oxygen supply, leading to abnormal operation or failure of the equipment. 2. **Increased costs**: The production of nitrogen is usually more expensive than that of air, thus increasing the usage cost. 3. **Maintenance issues**: Some pneumatic devices may be designed specifically for use with instrument air, and using nitrogen may affect the device’s lifespan and performance. In summary, when deciding whether to use instrument air or nitrogen, it is necessary to consider the specific application environment and equipment requirements, in order to avoid the risks and cost issues that can arise from improper use. .

In my opinion, ignoring costs, nitrogen is much better than air as long as it is not used in enclosed spaces.