Diameter for factory-wide air distribution plumbing is sized with increased future demands in anticipation. Additionally, the pipes accumulate scales and specks of dust on the internal walls from long-term usage and the flow efficiency will be reduced. For these reasons, one size larger diameter than currently needed is generally selected.
When one size larger diameter is selected, the air flow increases by 3 times but the material cost increases only by 50%. Therefore, it is generally more beneficial to select tubes of larger diameter. The key to diameter sizing is to divide the system in two, “distribution” and “equipment connection” sections, and design to the following parameters.
|1.||Air volume to be handled|
|2.||Maximum air pressure used by air equipment|
|4.||Types and quantity of connection fittings in the system|
Pipe Diameter Sizing for Distribution
|1.||Suppress terminal pressure drop to less than 0.5Kg/cm2|
|2.||Size the pipe diameter based on the sum of air volume needed for all the equipment to be used.|
|3.||Set the initial air pressure higher in the amount of pressure drop than the maximum pressure needed for the highest rated air equipment.|
|4.||Select connection fittings with consideration for air flow resistances (see [Table])|
|5.||If pressure drop is a concern for long line lengths, provide an air tank in an intermediate location to prevent the pressure loss.|
Pipe Diameter Sizing for Equipment Connections
|1.||Size pipe diameter based on maximum air volume requirement of an individual device connected.|
Cautionary Points on Equipment Connection Pipes (nylon & urethane tubes)
|1.||Make certain that used tubes do not have any external damages.|
|2.||Cut off sections where damaged by repeated/prolonged usage.|
|3.||Do not bend/fold tubes near connection fittings. (Min. bend radius for 6mm DIA. tube: 30mm, 8mm DIA. : 50mm)|
|4.||When connecting to quick fitting threads, clean sealant off the internal threads of mating equipment.|
The configurations of compressed air systems are infinite. We hope these tips in determining pipe diameter will help in any future changes or creations of your air systems. For any pneumatic needs, please check out MISUMI‘s line of pneumatic tools and accessories.