How to Size Gas or Steam Motive Eductors for Evacuating Gases

SG and HG Eductor NozzlesUsing the Eductor Models SG and HG

The times given in the ML, MLE evacuation charts below are the time in minutes to evacuate 1 Ft3 to the pressure (vacuum) listed, from atmospheric pressure.

Note: Eductors for evacuations are sized at atmospheric outlet pressure. For liquid motives, these values calculated can be used with higher outlet pressures provided they do not exceed 5% of the motive pressure or 5 PSIG, which ever is lower. If higher outlet pressure is being used, consult with us.

Adjusting Formulas for Priming: Step 1 Multiply the Ft3 to be evacuated by 2, then go to Step 1 under Evacuation and proceed through the procedure described above.

Show TableLiquid Motive Evacuating Gases in Times Tables (click to show/hide table)


Show TableS.F. Size Factor Table (click to show/hide table)
Gas Eductor Sizing Table