Variable Speed Direct Drive Rotary Screw Compressor. 10 Year Airend Warranty.
STSD-VSD Series. Single-stage, direct drive, variable speed
STSD-20VSD, 20 HP VSD rotary screw compressor
Models in stock. Ships in 3 business days.
18 models, 15 to 475 HP. Tap a horsepower and the price changes with it.
List price
Priced on your quote
Your quote takes $1,000 off, $50 per horsepower
First year of service parts included
Not sure what size you need?
The South-Tek Air Compressor Selector sizes a unit from your SCFM, pressure, inlet temperature, humidity and elevation, then hands the result to the sales team.
Open the Air Compressor Selector- Models in stock
- Ships in 3 business days
- Get your quote in 24 hours
- No minimum order
STSD-VSD Series specifications and prices, every model
Every CFM figure is the rated delivery from the South-Tek sell sheet, measured according to ISO 1217:2009 Annex C. Prices are South-Tek list prices from the price sheet; the promotion price is the list price less $50 per horsepower, applied to the nameplate rating.
| Model | HP | CFM at 100 PSI | CFM at 125 PSI | CFM at 218 PSI | List price | Promotion price |
|---|---|---|---|---|---|---|
| STSD-15VSD | 15 | 62.86 | 55.09 | 37.79 | Request a quote | |
| STSD-20VSD | 20 | 85.11 | 74.16 | 49.09 | Request a quote | |
| STSD-25VSD | 25 | 105.24 | 93.94 | 63.21 | Request a quote | |
| STSD-30VSD | 30 | 134.55 | 110.53 | 76.28 | Request a quote | |
| STSD-40VSD | 40 | 182.22 | 162.80 | 113.71 | Request a quote | |
| STSD-50VSD | 50 | 222.48 | 199.17 | 141.26 | Request a quote | |
| STSD-60VSD | 60 | 265.21 | 238.37 | 171.98 | Request a quote | |
| STSD-75VSD | 75 | 334.43 | 300.88 | 204.47 | Request a quote | |
| STSD-100VSD | 100 | 434.02 | 410.71 | 286.05 | Request a quote | |
| STSD-125VSD | 125 | 518.42 | 473.57 | 332.66 | Request a quote | |
| STSD-150VSD | 150 | 688.28 | 621.54 | 440.37 | Request a quote | |
| STSD-180VSD | 180 | 829.54 | 719.36 | 515.59 | Request a quote | |
| STSD-220VSD | 220 | 952.79 | 861.68 | 619.07 | Request a quote | |
| STSD-250VSD | 250 | 1,092.99 | 989.52 | 709.47 | Request a quote | |
| STSD-270VSD | 270 | 1,295.70 | 1,035.78 | 743.02 | Request a quote | |
| STSD-335VSD | 335 | 1,584.22 | 1,427.07 | 1,013.88 | Request a quote | |
| STSD-425VSD | 425 | 1,783.74 | 1,756.20 | 1,266.03 | Request a quote | |
| STSD-475VSD | 475 | 2,159.49 | 1,819.76 | N/A | Request a quote | |
Scroll sideways for more columns.
N/A means the sell sheet does not rate that model at that pressure.
Models without a listed price are priced on your quote; $50 per horsepower still comes off it. Inlet temperature, humidity and elevation affect delivered air. Your quote covers them.
About the STSD-VSD Series, in South-Tek's words
The STSD-VSD Series
At South-Tek, our mission is to power yours.
Each component designed for ease of maintenance and reducing operating costs.
Model range 30hp - 600hp (22kw-450kw).
Built and tested
Built with AKG coolers, WEG motors, Hoerbiger inlet valves and CMC controllers.
South-Tek compressors are tested under tough conditions for four hours, measuring critical parameters such as thermal stresses.
One vendor
South-Tek Systems has engineered on-site compressed air and gas systems for mission-critical operations since 2003.
We provide mission-critical complete air and gas solutions through our distribution network, offering a full suite of products from nitrogen generators to compressors, filters, and dryers.
One vendor for the compressor, the dryer and the filtration.
Our commitment to service includes ensuring customers select the optimal compressor for their specific requirements.
What you get with the STSD-VSD Series
- VSD matches output to demand: 15-25% energy savings vs. fixed-speed.
- 10 Year Airend Warranty.
- IE3 motor.
- Soft start inverter.
- Ultra quiet to reduce workplace noise.
- User-friendly remote monitoring, control and feedback support to optimize operations.
- Maximum performance in difficult conditions (operating temperature 45°C and above).
- DOE compliant.
- Ease of service.
Savings estimates based on specific use cases and may vary.
Motor, controller and cooler
What ships in every STSD-VSD Series cabinet, and the options you can add. Photos from the South-Tek sell sheet.
Motor
- WEG motor.
- IE3 motor.
- Nonproprietary, off-the-shelf motors reduce costs and simplify servicing.
- Compressors up to 40 HP use Tri-Voltage motors; 50 HP and above are standard 460V.
- Equipped with Class F insulation.
Controller
- Intuitive touch display option.
- Built-in phase protection.
- Prime and Fan motor current protection.
- Durable ABS plastic enclosure.
- IP65 fascia protection.
- MODBUS ready.
- Industry 4.0 / IOT ready.
- Factory or Aftermarket IOT Option module.
Cooler
- Up to 60% more compact than traditional fin-and-tube designs.
- Durable bar-and-plate construction.
- Minimizes airside fouling for optimal efficiency.
- Low speed radial fan and inverter for increased durability and long service life.
Options
- Capacity control valve (optional) to allow for maximum customization to suit your needs.
- Heat recovery (optional) offers premium efficiency for maximum energy savings.
- Water cooling (optional) offers premium efficiency for maximum energy savings.
- Frequency controlled (inverter) to allow for maximum customization to suit your needs.
Questions plant engineers ask
Is the STSD-VSD Series in stock, and how fast does it ship?
Models in stock. Ships in 3 business days.
How fast will I get a quote?
Get your quote in 24 hours. Send the model number, or the CFM and pressure you need, and we come back with a quote in 24 hours.
What do the CFM figures mean?
Each CFM figure is the rated air delivery for that model at that discharge pressure, measured according to ISO 1217:2009 Annex C. Every number on this page is copied from the South-Tek sell sheet.
Inlet temperature, humidity and elevation affect delivered air. Your quote covers them.
What electrical service does it need?
Compressors up to 40 HP use Tri-Voltage motors; 50 HP and above are standard 460V.
Tell us your voltage on the quote request and we confirm the motor for your model.
I am replacing an old unit. Does the $50 per horsepower discount apply?
$50 off per horsepower on every unit. There is no age requirement on the unit you are replacing. No paperwork to prove anything. It applies whether this is your first rotary screw package or your fifth. First year of service parts included.
Fixed speed or VSD, which do I need?
A fixed speed compressor runs its motor at one speed and delivers its rated CFM whenever it is loaded. It suits a steady air demand. A VSD compressor changes motor speed to follow the air you are using. It suits a demand that swings through the shift. VSD matches output to demand: 15-25% energy savings vs. fixed-speed. Savings estimates based on specific use cases and may vary.
If your demand is steady, look at the STSD Series.
STSD-VSD Series sell sheet
Every CFM figure on this page is copied from it.
Ready for a quote on the STSD-VSD Series?
$50 off per horsepower. First year of service parts included. Get your quote in 24 hours. Models in stock. Ships in 3 business days.