Air lines that are too long or with dimensions that are too small mean pressure drops. This means power losses. The exhaust line must have a larger dimension than the supply line.
This is because the exhaust air occupies a larger volume than the supply air. For an inlet pressure of 6.3 bars (= 7.3 bars absolute) and an outlet pressure at atmospheric level (= 1 bar absolute) the volume increase is a factor of 7.3. In practice this means that if the same dimensions are used for inlet and outlet lines a back pressure is built up and the motor loses its efficiency.
To ensure reliable service an air filter and lubricator (if the motor is not lubrication free) should be fitted into the inlet airline – within 5 meters from the motor. It is recommended that a pressure regulator is also incorporated into the air preparation package. This has the function of maintaining the desired working pressure, and can be used to modify the output exactly to meet the needs of the application.
To remember: When selecting an air preparation package, ensure all components have a flow capacity sufficient to meet the requirements of the motor.
To achieve optimum service life and performance an air motor should be supplied with 50 mm ³ of oil for each cubic meter (1000 liters) of air consumed. Insufficient lubrication will result in accelerated vane wear and a reduction in performance.