FIAC AIRBLOK Oil-Injected Rotary Screw Air Compressors

The AIRBLOK series is Werther International's enclosed rotary screw line, built by FIAC and sold in four drive configurations that together cover 10 to 125 HP and 42 to 494 CFM. The AIRBLOK series of enclosed air compressors is very versatile offering belt drive, direct drive, and variable speed drive options. Every unit ships inside a sound attenuating enclosure and runs between 65 and 75 dB(A). Which configuration fits depends on horsepower, how steady your air demand is, and how much you want to spend on electricity over the life of the machine.

 

How Oil Injection Works in an AIRBLOK Compressor

An oil injected rotary screw compressor introduces lubricant directly into the compression chamber as the two rotors turn. The oil is doing several jobs simultaneously, and understanding them explains why this design suits continuous industrial duty.

The injected oil seals the clearance between the rotors and the housing, which is what allows the screw element to build pressure without metal-to-metal contact. It also absorbs the heat of compression as it happens, keeping discharge temperatures low enough for the unit to run loaded for long stretches. Because the rotors never touch, wear is minimal and service intervals stay long.

An aftercooler ad downstream separation return the oil to the sump and drop air temperature before the air leaves the package. If your process cannot tolerate any oil carryover at all, the quiet oil-free air compressors line is the correct starting point instad.

Belt Drive or Direct Drive

The transmission between motor and air end is the first decision to make, and horsepower usually settles it. AIRBLOK belt drive units cover 10 to 60 HP. Direct drive units start at 75 HP and run to 125 HP.

Belt drive on the AIRBLOK uses an automatic tensioning design, so the belt stays correctly loaded without periodic manual adjustment. That keeps transmission efficiency stable over time and makes the belt itself a low-cost wear item when it does need replacement. For a 10 HP or 20 HP installation, belt drive is the economical route.

Direct drive removes the belt entirely. A maintenance-free coupler joins the TEFC high-efficiency electric motor straight to the air end, which delivers maximum transmission efficiency with no tensioning component to service. At 75 HP and above, the electricity saved by eliminating belt losses outweighs the higher build cost, which is why the AIRBLOK line switches to direct drive at that point.

When Variable Speed Earns Its Cost

A fixed-speed compressor runs at one motor speed and unloads when demand drops, which wastes energy every time your plant draws less air than the machine produces. Variable frequency drive changes the motor speed to match actual consumption, holding an equilibrium between energy drawn and air delivered.

The payback depends entirely on how variable your demand is. A shop running one shift with steady tool usage may never recover the premium. A facility with shift changes, seasonal swings, or intermittent large draws will typically see the difference on the utility bill within the first year. AIRBLOK variable speed models also carry lower maintenance costs than the fixed-speed equivalents, and the belt drive with variable speed line is the most efficient unit in the Werther catalog to operate.

Variable speed is offered on both transmissions. Belt drive with variable speed covers 25 to 50 HP. Direct drive with variable speed covers 40 to 125 HP, so the 40 and 50 HP bands are available either way.

AIRBLOK Configurations Compared

The ranges below show where they overlap and where only one option exists.

Sizing an AIRBLOK by Horsepower

Compressor sizing works backward from the CFM your tools and processes actually consume, then adds headroom. The AIRBLOK spec tables list CFM at each horsepower, so you can work from the demand figure rather than guessing at HP.

At the small end, the AIRBLOK 10/2 BD delivers 42 CFM and the 15/2 BD delivers 58 CFM, which covers most single-line operations and small machine shops. A 20 HP rotary screw air compressor in this series, the AIRBLOK 20/2 BD, produces 85 CFM. Mid-range plants running multiple stations typically land in the 30 to 60 HP band, from 119 to 242 CFM. Above that, the direct drive units carry high-volume plants from 318 CFM up to 494 CFM on the 125 HP variable speed model.

Undersizing forces the unit to run loaded constantly and shortens its life. Oversizing on a fixed-speed machine means paying for unload cycles you do not need, which is the situation variable speed is designed to solve. If your demand figure sits near a boundary between two models, the variable speed option removes the risk of choosing wrong.

Sound Levels and Enclosure Design

Every AIRBLOK unit measures between 65 and 75 dB(A), with the belt drive models at the quiet end of that range. Several design elements produce those numbers, and they work in combination rather than individually.

The sound attenuating enclosure is the visible one, but two-stage vibration isolation between the compressor assembly and the frame does as much work, since structure-borne vibration is what travels through a concrete floor into adjacent areas. A thermostatically controlled axial cooling fan handles the rest, running only as hard as discharge temperature requires instead of at full speed continuously.

The practical result is that AIRBLOK units can be installed inside a production space rather than isolated in a separate compressor room. Every belt drive model in the line runs at 68 dB(A) or below.

Standard Equipment on Every AIRBLOK Unit

The AIRBLOK ships as a complete package. Nothing on the list below is an upcharge.

• WYE Delta starter

• TEFC high-efficiency electric motor

• Sound attenuating enclosure

• FIAC air energy control microprocessor panel

• Aftercooler

• Thermostatically controlled axial cooling fan

• Two-stage vibration isolation

Belt drive models are additionally offered in three outlet pressure settings of 115, 145, and 190 PSI, so the discharge pressure can be matched to the process rather than regulated down from a single fixed setting.

Industries Running AIRBLOK Compressors

Werther supplies AIRBLOK units to operations ranging from single-facility producers to multi-plant industrial manufacturers. The oil-injected screw design and the 10 to 125 HP span make it a fit wherever compressed air runs continuously and floor noise matters.

• CNC machine shops

• Automotive

• Plastics

• Food and beverage

• Textile

• Aerospace

• Chemical and petrochemical

• Electronics

If none of the standard configurations fits your installation, Werther builds to specification through custom design services.

Request a Quote on an AIRBLOK Compressor

Part numbers, CFM at pressure, and brochure downloads sit on each configuration page. Send us the CFM your operation draws and the pressure you need at the point of use, and we will identify the AIRBLOK model that matches.

Request a quote or call 800-972-7668.