Because air systems operate at relatively low pressure, the components can be made of relatively inexpensive material - often by mass production processes such as plastic injection molding, or zinc or aluminum die-casting. Two main advantages of air-operated circuits are their low initial cost and design simplicity. Most pneumatic circuits run at low power - usually around 2 to 3 horsepower. Again the fluid is different but the operating characteristics change little. Hydraulic systems may use a variety of fluids - ranging from water (with or without additives) to high-temperature fire-resistant types. The gas may be different but the system's operating characteristics are the same.
Because nitrogen is usually supplied in gas cylinders at high pressure, it has a very low dew point at normal system pressure. Readily available nitrogen gas is not hazardous to the atmosphere or humans. While these systems are the same in many aspects, they can have very different characteristics in certain ways.įor example: remote outdoor applications may use dry nitrogen gas in place of compressed air to eliminate freezing problems. Most fluid power circuits use compressed air or hydraulic fluid as their operating media.
