Different materials can be used for compressed air header; materials include steel, black iron, stainless or anodized aluminum. It is critical that the material being installed has a pressure and temperature rating with an appropriate safety factor to support the compress air pressure requirement. Do not under-size pipe. The cost different between one pipe diameter and the next larger size is minimal. The larger the pipe diameter, the lower the pressure loss will be due to friction. A larger diameter pipe allows for additional compressed air during peak use periods and positions the system for future expansion. The compressed air velocity in the main distribution header should not exceed 30ft/s.
A compressed air drop leg, also referred to as a feeder line, begins with a TEE assembly that directs the compressed air in a vertical path. This unique flow pattern will guard against liquid or particulate contamination passing to a pneumatic process.
Each compressed air drop should include a TEE directing compressed air supply to its specified use. The base of the drop leg incorporators a drain valve. Each drop leg might include an FRL (pointof-use filter, regulator and lubricator).