Vacuum Pump Displacement Coversions

cfm = .472 L/sec

cfm = 28.316 L/min.

m3/hr. = .589 cfm

m3/hr. = 16.667 L/min.

m3/hr. = .278 L/sec.

L/sec. = 2.119 cfm

L/sec. = 3.60 m3/hr.

L/min. = .035 cfm

L/min. = .060 m3/hr.

Pumpdown Time Calculation

The theoretical pumpdown time of a vacuum chamber assuming no conductance between the pump and the chamber is given by:     Where:   S = Pumping Speed       (Free Air Displacement CFM)     V = Volume of Vacuum Chamber (cubic feet)     Where:   P0 = Atmospheric Pressure     P = Desired Pressure   Sample Calculation: Calculate the time required to evacuate a 10 cubic foot chamber to 5x10-2 Torr using a 25cfm mechanical pump.