Rotary screw compressors with belt drive

Compact design with impressive performance

Kaeser's line of small rotary screw air compressors is suitable for machine shops, auto repair and collision work, and anyone needing an efficient and reliable compressed air system.

Kaeser SX, SM, SK, and AS series of rotary screw compressors with V-belt drive provide outstanding efficiency and reliability. They feature the energy-saving SIGMA profile rotor and integrated SIGMA CONTROL 2 controller. 

  • 3 to 30 hp
  • Pressure: 125, 160, or 217 psig
  • Flow rate: 9 – 143 cfm

Options include:

  • T-Models: Integrated refrigerated dryer for high compressed air quality;
  • SFC Models: Variable speed drive (VSD) to efficiently meet varying demand (SM, SK and AS series).

Not sure which model you need? We're happy to help you determine the right solution. Contact us to get started.

Your advantages

  • Highly-efficient power transmission:
    The quality drive belt with automatic tensioning device ensures consistent transmission efficiency over the life of the unit and reduces maintenance costs.
  • Easy maintenance:
    Maintenance is quick thanks to the removable service panels and easy component access.
  • Exceptionally quiet:
    The soundproofed housing keeps noise levels at a minimum so there's no need to install it in a separate room. In fact, you can have a conversation right next to the compressor.

Low life cycle costs
Life-cycle costs

Our comprehensive approach to life cycle cost management: Superior efficiency, easy operation, service-friendliness, and the latest in technology to keep performance high well into the future.

 

Take a closer look at our belt drive rotary screw compressors

Series comparison

Standard Drive Power range hp Flow rate cfm Pressure psig
SX Multi-ribbed belt 3 - 7.5 9 – 28 125/160/217
SM Multi-ribbed belt 7.5 - 15 19 - 57 125/160/217
SK Multi-ribbed belt 15 – 20 46 - 88 125/160/217
AS Multi- ribbed belt 20 – 30 64 – 141 125/160/217

Find the right compressor

Save money and reduce energy costs by selecting a compressor with just the right amount of power to suit your needs. Ask us – we're happy to help you select the right unit.

SX Series Rotary Screw Compressors – Equipment

Complete unit

SX rotary screw compressor – open

  • Ready-to-run
  • Fully automatic
  • Super soundproofing
  • Vibration dampening
  • Powder-coated panels
  • For ambient temperatures up to +115°F
  • Easy access to all service points

Airend

  • Single stage with cooling fluid injection for optimal rotor cooling
  • Genuine KAESER rotary screw airend with energy-saving SIGMA profile
  • Multi-ribbed, single belt drive

Drive

Maintenance-free elastic belt

Cooling fluid and air circuit

  • Dual flow fan and separate air flow channels for motor cooling, the fluid/compressed air cooler, the control cabinet and interior of the machine
  • Dry air filter
  • Pneumatic inlet and venting valves
  • Cooling fluid separator tank with triple separation system
  • Safety relief valve
  • Minimum pressure check valve
  • Thermostatic valve and fluid filter in coolant circuit
  • Fluid / compressed air combination cooler
  • All fully piped
  • Flexible couplings

Heat recovery (HR) (Option)

Optionally available with integrated heat recovery system (stainless steel plate-type heat exchanger)

Integrated refrigerated dryer (T-models)

  • CFC-free
  • R-134a refrigerant
  • Fully insulated
  • Hermetically sealed refrigerant circuit
  • Refrigerant compressor with energy-saving, cycling shut-down feature
  • Hot gas bypass control
  • Zero loss electronic condensate drain (ECO-DRAIN)
  • Linked to operational status of the compressor when inactive
  • Continuous operation can be selected on site

Electric motor

  • Premium efficiency IE3
  • Totally enclosed fan-cooled motor (TEFC)
  • Class F insulation for greater power reserve

Electrical components

  • Control cabinet to IP 54
  • Control transformer
  • Siemens frequency converter (SFC models)
  • Automatic wye-delta starter
  • Overload relays
  • Control cabinet ventilation

SIGMA CONTROL 2

SIGMA CONTROL 2 compressor controller

  • "Traffic-light" LED indicators show operational status at a glance
  • Plain text display
  • 30 selectable languages
  • Soft-touch keys with icons
  • Fully automated monitoring and control
  • Dual, Quadro, Vario, Dynamic, and Continuous control included as standard
  • Interfaces: Ethernet
  • Additional optional communications modules for: Profibus DP, Modbus, Profinet, DeviceNet, and EtherNet/IP
  • SD card slot for data-logging and updates
  • RFID reader
  • Web server

SM Series Rotary Screw Compressors – Equipment

Complete unit

SM rotary screw compressor – open

  • Ready-to-run
  • Fully automatic
  • Super soundproofing
  • Vibration dampening
  • Powder-coated panels
  • For ambient temperatures up to +115 °F
  • Easy access to all service points

Airend

  • Single stage with cooling fluid injection for optimal rotor cooling
  • Genuine KAESER screw compressor airend with SIGMA Profile
  • Multi-ribbed, single belt drive

Drive

V-belt drive with automatic belt tensioning

Cooling fluid and air circuit

  • Dual flow fan and separate air flow channels for motor cooling, the fluid/compressed air cooler, control cabinet, the control cabinet and interior of the machine
  • Dry air filter
  • Pneumatic inlet and venting valves
  • Cooling fluid separator tank with triple separation system
  • Safety relief valve
  • Minimum pressure check valve
  • Thermostatic valve and fluid filter in coolant circuit
  • Fluid / compressed air combination cooler
  • All fully piped
  • Flexible couplings

Heat recovery (HR) (Option)

Optionally available with integrated heat recovery system (stainless steel plate-type heat exchanger)

Integrated refrigerated dryer (T-models)

  • CFC-free
  • R-134a refrigerant
  • Fully insulated
  • Hermetically sealed refrigerant circuit
  • Refrigerant compressor with energy-saving, cycling shut-down feature
  • Hot gas bypass control
  • Zero loss electronic condensate drain (ECO-DRAIN)
  • Linked to operational status of the compressor when inactive
  • Continuous operation can be selected on site

Electric motor

  • Super Premium Efficiency IE4 (SM 7.5 — IE3)
  • Totally enclosed fan-cooled motor (TEFC)
  • Class F insulation for greater power reserve

Electrical components

  • Control cabinet IP 54
  • Control transformer
  • Siemens frequency converter (SFC models)
  • Automatic wye-delta starter
  • Overload relays
  • Control cabinet ventilation

SIGMA CONTROL 2

SIGMA CONTROL 2 compressor controller

  • "Traffic-light" LED indicators show operational status at a glance
  • Plain text display
  • 30 selectable languages
  • Soft-touch keys with icons
  • Fully automated monitoring and control
  • Dual, Quadro, Vario, Dynamic, and Continuous control included as standard
  • Interfaces: Ethernet
  • Additional optional communications modules for: Profibus DP, Modbus, Profinet, DeviceNet and EtherNet/IP
  • SD card slot for data-logging and updates
  • RFID reader
  • Web server

SK Series Rotary Screw Compressors – Equipment

Complete unit

AIRCENTER SK – removable enclosure cover

  • Ready-to-run
  • Fully automatic
  • Super soundproofing
  • Vibration dampening
  • Powder-coated panels
  • For ambient temperatures up to +115°F
  • Easy access to all service points

Airend

  • Single stage with cooling fluid injection for optimal rotor cooling
  • Genuine KAESER rotary screw airend with SIGMA Profile
  • Multi-ribbed, single belt drive

Drive

V-belt drive with automatic belt tensioning

Cooling fluid and air circuit

  • Dual flow fan and separate air flow channels for motor cooling, the fluid/compressed air cooler, the control cabinet and interior of the machine
  • Dry air filter
  • Pneumatic inlet and venting valves
  • Cooling fluid separator tank with triple separation system
  • Safety relief valve
  • Minimum pressure check valve
  • Thermostatic valve and fluid filter in coolant circuit
  • Fluid / compressed air combination cooler
  • All fully piped
  • Flexible couplings

Heat recovery (HR) (Option)

Optionally available with integrated heat recovery system (stainless steel plate-type heat exchanger)

Integrated refrigerated dryer (T-models)

  • CFC-free
  • R-134a refrigerant
  • Fully insulated
  • Hermetically sealed refrigerant circuit
  • Refrigerant compressor with energy-saving, cycling shut-down feature
  • Zero loss electronic condensate drain (ECO-DRAIN)
  • Linked to operational status of the compressor when inactive
  • Continuous operation can be selected on site

Electric motor

  • Premium Efficiency IE3
  • Totally enclosed fan-cooled motor (TEFC)
  • Class F insulation for greater power reserve

Electrical components

  • Control cabinet IP 54
  • Control transformer
  • Siemens frequency converter (SFC models)
  • Automatic wye-delta starter
  • Overload relays
  • Control cabinet ventilation

SIGMA CONTROL 2

SIGMA CONTROL 2 compressor controller

  • "Traffic-light" LED indicators show operational status at a glance
  • Plain text display
  • 30 selectable languages
  • Soft-touch keys with icons
  • Fully automated monitoring and control
  • Dual, Quadro, Vario, Dynamic, and Continuous control included as standard
  • Interfaces: Ethernet
  • Additional optional communications modules for: Profibus DP, Modbus, Profinet, DeviceNet, and EtherNet/IP
  • SD card slot for data-logging and updates
  • RFID reader
  • Web server

AS Series Rotary Screw Compressors – Equipment

Complete unit

ASK rotary screw compressor

  • Ready-to-run
  • Fully automatic
  • Super soundproofing
  • Vibration dampening
  • Powder-coated panels
  • For ambient temperatures up to +115 °F
  • Easy access to all service points

Airend

  • Single stage with cooling fluid injection for optimal rotor cooling
  • Genuine Kaeser rotary screw airend with SIGMA Profile
  • Multi-ribbed, single belt drive

Drive

V-belt drive with automatic belt tensioning

Cooling fluid and air circuit

  • Dual flow fan and separate air flow channels for motor cooling, the fluid/compressed air cooler, the control cabinet and interior of the machine
  • Dry air filter
  • Pneumatic inlet and venting valves
  • Cooling fluid reservoir with three-stage separator system
  • Safety relief valve
  • Minimum pressure/check valve
  • Thermostatic valve and micro-filter in coolant circuit
  • Fluid/compressed air combination cooler
  • All fully piped
  • Flexible couplings

Heat recovery (HR)

Optionally available with integrated heat recovery system (plate-type heat exchanger)

Integrated refrigerated dryers (T-models)

  • CFC-free
  • R-134a refrigerant
  • Fully insulated
  • Hermetically sealed refrigerant circuit
  • Rotary refrigerant compressor with energy-saving, cycling shut-down feature
  • Hot gas bypass control
  • Zero loss electronic condensate drain (ECO-DRAIN)
  • Linked to operational status of the compressor when inactive
  • Continuous operation can be selected onsite

Electric motor

  • Premium efficiency IE3
  • Totally enclosed fan-cooled motor (TEFC)
  • Class F insulation for greater power reserve

Electrical components

  • Control cabinet IP 54
  • Control transformer
  • Siemens frequency converter (SFC models)
  • Automatic wye-delta starter
  • Overload relays
  • Control cabinet ventilation

SIGMA CONTROL 2

SIGMA CONTROL 2 compressor controller

  • "Traffic-light" LED indicators show operational status at a glance
  • Plain text display
  • 30 selectable languages
  • Soft-touch keys with icons
  • Fully automated monitoring and control
  • Dual, Quadro, Vario, Dynamic, and Continuous control included as standard
  • Interfaces: Ethernet
  • Additional optional communications modules for: Profibus DP, Modbus, Profinet,DeviceNet, and EtherNet/IP
  • SD card slot for data-logging and updates
  • RFID reader
  • Web server

Technical specifications SX

Standard version

ModelSX 3 SX 4 SX 5
Working pressure psi 125 160 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 12 9 16 13 9 21 17 13
Max. positive pressure psi 125 160 125 160 217 125 160 217
Nominal motor output hp 3 4 5
Dimensions W x D x H in 23 x 25 x 38 23 x 25 x 38 23 x 25 x 38
Compressed air connection¾ NPT ¾ NPT ¾ NPT
Sound pressure level dB(A) 61 62 63
Weight lb 309 309 320

ModelSX 7.5
Working pressure psi 125 160 217
Flow rate Complete system at working pressure acfm 28 24 19
Max. positive pressure psi 125 160 217
Nominal motor output hp 7.5
Dimensions W x D x H in 23 x 25 x 38
Compressed air connection¾ NPT
Sound pressure level dB(A) 66
Weight lb 342

T version

ModelSX 3 T SX 4 T SX 5 T
Working pressure psi 125 160 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 12 9 16 13 9 21 17 13
Max. positive pressure psi 125 160 125 160 217 125 160 217
Nominal motor output hp 3 4 5
Dimensions W x D x H in 23 x 36 x 38 23 x 36 x 38 23 x 36 x 38
Compressed air connection¾ NPT ¾ NPT ¾ NPT
Sound pressure level dB(A) 61 62 63
Weight lb 408 408 419

ModelSX 7.5 T
Working pressure psi 125 160 217
Flow rate Complete system at working pressure acfm 28 24 19
Max. positive pressure psi 125 160 217
Nominal motor output hp 7.5
Dimensions W x D x H in 23 x 36 x 38
Compressed air connection¾ NPT
Sound pressure level dB(A) 66
Weight lb 441

Technical specifications SM

Standard version

ModelSM 7.5 SM 10 SM 15
Working pressure psi 125 160 217 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 32 26 19 46 37 28 55 46 36
Max. positive pressure psi 125 160 217 125 160 217 125 160 217
Nominal motor output hp 7.5 10 15
Dimensions W x D x H in 25 x 31 x 43 25 x 31 x 43 25 x 31 x 43
Compressed air connection¾ NPT ¾ NPT ¾ NPT
Sound pressure level dB(A) 65 67 68
Weight lb 485 529 529

T version

ModelSM 7.5 T SM 10 T SM 15 T
Working pressure psi 125 160 217 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 32 26 19 46 37 28 55 46 36
Max. positive pressure psi 125 160 217 125 160 217 125 160 217
Nominal motor output hp 7.5 10 15
Dimensions W x D x H in 25 x 43 x 43 25 x 43 x 43 25 x 43 x 43
Compressed air connection¾ NPT ¾ NPT ¾ NPT
Sound pressure level dB(A) 65 67 68
Weight lb 650 694 694

Technical specifications SFC

SFC version

ModelSFC 8
Working pressure psi 125 160 217
Flow rate Complete system at working pressure acfm 12 - 48 12 - 41 13 - 31
Max. positive pressure psi 125 160 217
Nominal motor output hp 10
Dimensions W x D x H in 25 x 31 x 43
Compressed air connection¾ NPT
Sound pressure level dB(A) 68
Weight lb 551

T-SFC version

ModelSFC 8 T
Working pressure psi 125 160 217
Flow rate Complete system at working pressure acfm 12 - 48 12 - 41 13 - 31
Max. positive pressure psi 125 160 217
Nominal motor output hp 10
Dimensions W x D x H in 25 x 43 x 43
Compressed air connection¾ NPT
Sound pressure level dB(A) 68
Weight lb 717

Technical specifications SK

Standard version

ModelSK 15 SK 20
Working pressure psi 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 71 59 46 88 77 63
Max. positive pressure psi 125 160 217 125 160 217
Nominal motor output hp 15 20
Dimensions W x D x H in 30 x 35 x 50 30 x 35 x 50
Compressed air connection1 NPT 1 NPT
Sound pressure level dB(A) 67 68
Weight lb 686 703

T version

ModelSK 15 T SK 20T
Working pressure psi 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 71 59 46 88 77 63
Max. positive pressure psi 125 160 217 125 160 217
Nominal motor output hp 15 20
Dimensions W x D x H in 30 x 49 x 50 30 x 49 x 50
Compressed air connection1 NPT 1 NPT
Sound pressure level dB(A) 67 68
Weight lb 851 869

Technical specifications SFC

SFC version

ModelSFC 11 SFC 15
Working pressure psi 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 22 - 72 22 - 62 19 - 48 28 - 95 29 - 83 28 - 68
Max. positive pressure psi 125 160 217 125 160 217
Nominal motor output hp 15 20
Dimensions W x D x H in 30 x 35 x 50 30 x 35 x 50
Compressed air connection1 NPT 1 NPT
Sound pressure level dB(A) 68 69
Weight lb 723 741

T-SFC version

ModelSFC 11 T SFC 15 T
Working pressure psi 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 22 - 72 22 - 62 19 - 48 28 - 95 29 - 83 28 - 68
Max. positive pressure psi 125 160 217 125 160 217
Nominal motor output hp 15 20
Dimensions W x D x H in 30 x 49 x 50 30 x 49 x 50
Compressed air connection1 NPT 1 NPT
Sound pressure level dB(A) 68 69
Weight lb 888 906

Technical specifications AS

Standard version

ModelAS 20 AS 25 AS 30
Working pressure psi 125 160 217 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 99 85 64 120 102 85 141 122 100
Max. positive pressure psi 125 160 217 125 160 217 125 160 217
Nominal motor output hp 20 25 30
Dimensions W x D x H in 32 x 44 x 60 32 x 44 x 60 32 x 44 x 60
Compressed air connection1¼ NPT 1¼ NPT 1¼ NPT
Sound pressure level dB(A) 67 69 71
Weight lb 1,069 1,113 1,157

T version

ModelAS 20 T AS 25 T AS 30 T
Working pressure psi 125 160 217 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 99 85 64 120 102 85 141 122 100
Max. positive pressure psi 125 160 217 125 160 217 125 160 217
Nominal motor output hp 20 25 30
Dimensions W x D x H in 32 x 58 x 60 32 x 58 x 60 32 x 58 x 60
Compressed air connection1¼ NPT 1¼ NPT 1¼ NPT
Sound pressure level dB(A) 67 69 71
Weight lb 1,279 1,323 1,367

Technical specifications SFC

SFC version

ModelSFC 18S SFC 22S
Working pressure psi 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 33 - 119 27 - 105 29 - 85 33 - 141 27 - 125 29 - 103
Max. positive pressure psi 125 160 217 125 160 217
Nominal motor output hp 25 30
Dimensions W x D x H in 32 x 44 x 60 32 x 44 x 60
Compressed air connection1¼ NPT 1¼ NPT
Sound pressure level dB(A) 70 72
Weight lb 1,168 1,213

T-SFC version

ModelSFC 18S T SFC 22S T
Working pressure psi 125 160 217 125 160 217
Flow rate Complete system at working pressure acfm 33 - 119 27 - 105 29 - 85 33 - 141 27 - 125 29 - 103
Max. positive pressure psi 125 160 217 125 160 217
Nominal motor output hp 25 30
Dimensions W x D x H in 32 x 58 x 60 32 x 58 x 60
Compressed air connection1¼ NPT 1¼ NPT
Sound pressure level dB(A) 70 72
Weight lb 1,378 1,422