Instruction Manual
Airmac Air Compressors
2019-06-07
© Glenco Air & Power Pty Ltd
19
remote air inlets, relocate the compressor, or construct a ventilated enclosure or baffle walls.
5.6
Discharge and Condensate Piping
All piping, fittings, air receiver tanks, and so on connected to the compressor discharge must be
certified safe for the unit’s discharge pressure and temperature. Do not use PVC plastic in the
compressed air discharge line.
Use pipe thread sealant on all threads and assemble joints tightly to prevent air leaks and energy
wastage.
Mainline piping used to convey air throughout a system should be sized to accommodate the
maximum flow rate of the compressor, which is also referred to as its free air delivery. A basic guide
to the selection of minimum pipe size diameter for a given flow rate and pipeline length is given in
Table 5-1, or one can refer to the detailed selection guides that are available for the various types of
proprietary compressed air piping systems. Branch piping should be sized in a similar manner, but
the design flow rate should instead be based on the total air consumption of the tools or appliances
running off that branch.
To allow for vibration and to prevent piping stresses being transmitted to the compressor, the
connection between the unit’s discharge valve and the mainline piping system should be made using
a flexible air hose or coupling.
The minimum air hose internal diameter (ID) can be selected in accordance with Table 5-2 or by
referring to the hose manufacturer’s guidelines, and again with consideration as to whether the hose
is a main distribution line or a branch line.
One should always err to the larger size when selecting compressed air pipes or hoses, as a too-small
line increases pressure drop and energy loss. A larger air line is more energy efficient, provides
additional air storage capacity and reduces the severity of air pressure fluctuations during use.
Table 5-1
Recommended Minimum Pipe Size for Compressed Air Lines
(Schedule 40 Steel Pipe)
L
ength of Pipeline (metres)
Flow
(L/m)
7.5
15
22.5
30
45
60
75
90
142
½”
½”
½”
½”
½”
½”
½”
½”
283
½”
½”
½”
¾”
¾”
¾”
¾”
¾”
425
½”
¾”
¾”
¾”
¾”
¾”
¾”
¾”
566
¾”
¾”
¾”
¾”
¾”
¾”
¾”
¾”
708
¾”
¾”
¾”
¾”
¾”
1”
1”
1”
849
¾”
¾”
¾”
¾”
1”
1”
1”
1”
991
¾”
¾”
1”
1”
1”
1”
1”
1”
1,132
¾”
1”
1”
1”
1”
1”
1”
1”
1,415
1”
1”
1”
1”
1”
1”
1”
1”
1,670
1”
1”
1”
1”
1-¼” 1-¼” 1-¼” 1-¼”