Pump Arrangement

Abstract

A pump arrangement comprising at least one first pump and at least one second pump that can be connected or is connected in series behind the first pump. The pump arrangement has a simple construction, lowest possible pump capacity requirements, and quickly establishes a required pressure or vacuum pressure. This is achieved in that a pump capacity of the first pump or a sum of the pump capacities of the first pumps is much greater than a pump capacity of the second pump and that a bypass with a first overflow valve is connected between the first pump and the second pump.

1 . A pump arrangement, comprising
 at least one first pump; and   at least one second pump that can be connected or is connected in series behind the first pump,   wherein a total pump capacity of the at least one first pump is much greater than a pump capacity of the second pump; and   that a bypass with a first overflow valve is connected between the first pump and the second pump.   
     
     
         2 . The pump arrangement according to  claim 1 , wherein a suction side of the second pump is also connected by means of a line that comprises a second overflow valve to a container to be evacuated and that a switchable valve is arranged between the first pump and the second pump. 
     
     
         3 . The pump arrangement according to  claim 1 , wherein the over-flow valve is a check valve. 
     
     
         4 . The pump arrangement according to  claim 2 , wherein the valve is a choke. 
     
     
         5 . The pump arrangement according to  claim 2 , wherein the valve can be switched electrically. 
     
     
         6 . The pump arrangement according to  claim 2 , wherein the valve can be controlled by differential pressure. 
     
     
         7 . The pump arrangement according to  claim 1 , wherein additional pumps are connected in series, wherein a bypass with an overflow valve is connected between each pair of pumps formed adjacent in series.