EMAX Two-Stage Piston Air Compressors

How a Two-Stage Air Compressor Works

A single-stage compressor squeezes air in one step and sends it straight to the tank. A two-stage (2 stage) compressor splits the job: a larger low-pressure cylinder compresses intake air partway, the air is cooled between stages, and a smaller high-pressure cylinder finishes the compression before the air enters the tank. Because each cylinder does only part of the work, the pump runs cooler and reaches higher pressure with less strain per stroke. Every compressor in this collection is rated for a maximum pressure of 175 PSI, and each listing shows CFM at max pressure, so you can see how much air the pump still produces at the top of its range.

Single-Stage vs Two-Stage: Which Do You Need?

Single-stage units suit light, intermittent use such as inflating tires or running a nailer now and then. A two-stage piston compressor makes more sense when several people use air at once, or when you run air-hungry tools like sanders, grinders, impact wrenches and spray guns for long stretches. If your facility needs high-volume air around the clock, compare these piston units with our EMAX rotary screw air compressors, or browse the full compressors range.

Sizing: CFM, Horsepower and 80 vs 120 Gallon Tanks

Size by airflow (CFM) first, then horsepower. Add up the CFM ratings of the tools that will run at the same time, compare that total with the CFM at your working pressure, and leave headroom for growth.

All tanks in this range are vertical, which saves floor space. An 80 gallon air compressor has the smaller footprint and a 3/4" air outlet. A 120 gallon air compressor stores more air, which helps cover short bursts of heavy use and reduces how often the motor starts; these models use a 1" air outlet.

Electrical: Phase, Voltage and Breaker Size

Match the compressor to the power you actually have. Single-phase models run on 230V; three-phase models come in 208–230V and 460V versions. The product data lists a recommended breaker for each:

Starting amps are much higher than full-load amps, and most models include a magnetic starter. Have a licensed electrician plan wiring and circuit protection according to the manufacturer's instructions and local electrical code.

Pump Lubrication, Duty Cycle and Motors

Pressure-lubricated pumps (APP4V1043TP and APP2I0524TP) carry an estimated pump life of 70,000 hours in the product data, while the splash-lubricated ESS models list 50,000 hours. Every model has a 60% duty cycle, and many are listed as continuous-run capable; the ESS07V080Z1 is noted as not rated for continuous-run service. Single-phase models use ODP (open drip-proof) motors, which need a clean, dry room. Three-phase models use TEFC motors, whose enclosed design is better suited to dusty shops.

Before You Install

• Circuit: confirm voltage, phase and breaker size against the listing.
• Space: check the uncrated dimensions and weight on each product page, plus clearance around the unit for service and airflow. These are heavy machines, so plan how you will move them into place.
• Ventilation: pick a cool, dry, well-ventilated spot so the pump draws clean air and sheds heat.
• Moisture: models with a manual drain need the tank drained regularly; automatic drains and refrigerated dryers help when you paint or run moisture-sensitive tools.
• Oil and service: pump oil capacity is listed per model (2 quarts or 1.75 quarts on most), and many models reference service kit EFKIT008AWBS.

Always follow the manufacturer's instructions and your site's safety program for installation, anchoring and operation.

Standard Units vs Packages

Standard models give you the compressor itself. Package versions (SKUs ending in PK) bundle extras that vary by model, such as a refrigerated air dryer rated at 30 CFM or 58 CFM with built-in prefilters, a dual-timer electric tank drain, and Silent Air on some units. Product data lists ETL, ASME and CRN certifications for these compressors. See the wider EMAX air compressors lineup for other configurations.