Description:

The Edwards E2M28 is a two-stage, oil-sealed rotary-vane pump engineered for clean-room reliability. Twin carbon-composite vanes spin in offset rotor chambers to pull 27 m³ h⁻¹ (19 CFM) at 50 Hz—or 33 m³ h⁻¹ (23 CFM) at 60 Hz—while an integral gas ballast lets condensable vapors pass without oil contamination. A pressure-regulated oil distribution valve prevents suck-back on shutdown and lubricates bearings from a 1.32 L Ultragrade-19 sump. The pump ships on a vibration-damped aluminum baseplate with an NW-25 KF inlet, ¾-in BSP exhaust nozzle and thermal-overload-protected 0.75 kW motor that runs 57 dB(A) quiet. Ultimate pressure hits 7 × 10⁻⁵ Torr (1 × 10⁻⁴ mbar), and water-vapor throughput reaches 0.7 kg h⁻¹—plenty for freeze-dryers and GC/MS systems. All wetted parts are aluminum alloy or stainless steel, allowing inert-gas purging for light solvent duty. At 97 lb the E2M28 is still bench-movable, yet its 45–65 °C running body temp resists varnishing even in 90 % RH labs.

Economic Advantage:

By delivering turbomolecular-pump backing performance in a single-phase, air-cooled frame, the E2M28 displaced chilled-water pumps and dry scrolls that cost twice as much and demanded more maintenance. Its shared platform with the smaller E2M18 minimized spare-parts inventories for service centers, and the durable vane design often runs 15 000 h between overhauls—cutting lifetime $/L s⁻¹ of pumping speed to industry-leading lows.