Rotary Vane Pump Systems


The combination of a chemical duty diaphragm pump with a rotary vane pump was developed to take advantage of the strong specifications of each type of pump.

The two-stage chemical duty diaphragm pump is able to withstand cor­rosive gasses and remove the resulting condensate prior to its absorption in the two-stage rotary vane pump oil by constantly distilling the oil during ope­ration.

The rotary vane pump provides a much lower ultimate vacuum and will have a long life with the pump oil being free of contaminates. The result is a vacuum pump system with the vacuum capabilities of a rotary vane pump combined with the solvent and acid handling capabilities of a PTFE diaphragm pump.

In addition to the standard system models, Welch offers further combination pump systems on request, including systems with different mains voltage and frequency.

Beside the rotary vane pump and the diaphragm pump, Chemvac vacuum systems consist of exhaust oil mist separator (AKD), separator bottle, oil box vacuum gauge, mains cable, plug, KF small flange connections, clamp and centering rings and Labovac 14 oil loading.

Applications: Vacuum manifold (Schlenk line), Freeze drying (Lyophilisation), Industrial Applications


The mobile laboratory rotary vane pump system has been specifically designed for use in chemistry laboratories. Its construction has intentionally been kept simple, compact and clearly arranged. The upstream cold traps enable even larger quantities of condensable vapors to be pumped without any additional pump load. The Dewar vessels protect the pump from chemical vapors. Moreover, the oil mist separator (AKD) captures any oil mist. A PIZA 111 cr-gold multi-range vacuum gauge for measuring the pressure can be easily attached to the stand rod.

The RVP-Trolley includes the following components:
-        Rotary vane vacuum pump ready-to-use with oil charging and mounted on the trolley
-        Motor protection switch, main power switch, mains cable and plug
-        Gas ballast valve
-        Oil mist separator
-        Two Dewar vessels
-        PIZA 111 cr-gold handheld gauge (selected models)
-        Connectors, flanges and flexible steel hose

Applications: Vacuum oven, Industrial, Vacuum manifold (Schlenk line), Concentrator

Roots system

The roots pump systems are complete, optimized and compact vacuum systems consisting of a roots pump and a two-stage rotary vane backing pump. Roots pump systems are well established in many fields of production and research where large pumping speeds are required at pressures in the rough and fine vacuum range. The roots blower is controlled via a frequency converter to allow ramp-up of roots blower and rotary vane pump at the same time.