Specifications

'Single Stage' versus 'Two Stage’
Reciprocating Units
Reciprocating Compressor Units are further classified as either Single Stage or Two Stage. These classifications deal
only with the Air Compressor Pump, and are a method of describing how the air is processed and brought from
atmospheric to maximum pressure.
A 'Single Stage' Pump is a Pump in which one or more Cylinders brings the
air from atmospheric to maximum pressure in a single stroke of the Piston. In
a Pump where there is more than one Piston, the Pistons are the same size.
Typically, Single stage Pumps can produce air pressures to a maximum of
125 psi, and are therefore limited in their use.
‘Figure 4' shows a typical 'Single Stage' Pump. Though a One Cylinder Pump
is shown, they are not limited to that (one Cylinder), as noted above.
A 'Two Stage' Pump is a Pump in which two
Cylinders/Pistons bring the air from atmospheric to
maximum pressure. The Cylinders/Pistons consist of one
large Piston (also known as the Low Pressure)and one
smaller one (known as the High Pressure).
During the first stage, the air enters the larger (or Low
Pressure) Cylinder, where it is compressed to approximately
50 psi. The air then travels through a cooling tube to the
smaller (or High Pressure) Cylinder (the second stage),
where it is further compressed to maximum pressure. Two
stage Pumps can generally produce air pressures to a
maximum of 175 psi to 200 psi, and are therefore more
suitable to automotive / industrial applications.
'Figure 5’ shows a typical 'Two Stage' Pump, indicating the
difference in the sizes between the first stage (Low Pressure)
Cylinder / Piston and the second stage (High Pressure)
Cylinder / Piston.
Two stage Pump may have more than two Cylinders and
Pistons.
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'Figure 4’
'Figure 5’
'Figure 4’
Low Pressure Piston
High Pressure Piston
What are the more common types of Units used ?
What are the more common types of Units used ?
What is a ‘Single Stage’ Pump?
What is a ‘Two Stage’ Pump?
Air Compressors
Information Bulletin IFB-01
March ‘07
For Sales & Service contact:
CENTRAIR Air Systems & Supplies 705-722-5747 [e-mail] www.centrair.ca