Oil-less Rotary Claw Compressors

Selectorr oil-less rotary claw compressors are ideal for air sparging, pneumatic conveying, and other low pressure applications. Standard models include an inlet silencer, inlet filter, and a pressure regulator. They are fitted with Nema flange motors, available in both standard and XP versions. Each model includes its own unique combination of motor, coupling/fan assembly, and pressure regulator.

Oil-less Rotary Claw Compressors
Base Model CA2 CA3 CA5 CA7L CA7 CA10 CA15
RPM 60/50 HZ 3450/2850 3450/2850 3450/2850 3450/2850 3450/2850 3450/2850 3450/2850
Inlet/Discharge Connections 1" 1 1/2" 1 1/2" 2" 2" 3" 3"
dB(A), Average 60 Hz 80 83 83 85 85 85 85
Weight with Largest Motor (lb.) 205 331 386 628 648 1036 1213
Gear Box Oil Capacity (quarts) 0.8 0.8 0.8 1.2 1.2 1.2 1.2
Configured Models:
CA2-5 CA3-7 CA5-10 CA7L-15 CA10-20 CA15-25
Motor HP 5 7.5 10 15 20 25
Dimensions drawing drawing drawing drawing drawing drawing
Part # (with motor) 264342 264380 264382 264384 264389 264393
Part # (without motor) 264342-LM 264380-LM 264382-LM 264384-LM 264389-LM 264393-LM
CA3-10 CA5-15 CA7L-20 CA7-20 CA10-25 CA15-40
Motor HP 10 15 20 20 25 40
Dimensions drawing drawing drawing drawing drawing drawing
Part # (with motor) 264381 264383 264385 264387 264390 264394
Part # (without motor) 264381-LM 264383-LM 264385-LM 264387-LM 264390-LM 264394-LM
CA7-25 CA10-30 CA15-50
Motor HP 25 30 50
Dimensions drawing drawing drawing
Part # (with motor) 264388 264391 264395
Part # (without motor) 264388-LM 264391-LM 264395-LM
CA10-40
Motor HP 40
Dimensions drawing
Part # (with motor) 264392
Part # (without motor) 264392-LM


Rotary claw compressors require little to no maintenance and can operate continuously and dependably for long periods of time. Inlet filters are typically used to trap contaminants from entering the compression chamber.

A claw compressor consists of two rotors. The rotors turn in opposite directions, without contact, with very tight clearances. They are synchronized via a precision gear. As the claw moves over the suction connection and the axial suction channel inlet, gas is sucked into the compression chamber.

The revolving rotors move gas from the suction side to the pressure side. Then it is compressed by the reduction of the volume between the rotors until the lower rotor uncovers the discharge channel. This "internal compression" leads to high differential pressures at efficiencies of more than 60%. To remove the heat generated by the compression process, cooling air is sucked in between the compression housing and a silencing cover before leaving the pump.