Function
It is well known that boiler feedwater pumps and condensate pumps must not drop below a certain minimum flow rate. Otherwise, this would result in unacceptably high heating of the feedwater or condensate. However, during specific boiler operating modes (such as start-up, sliding pressure operation, or low-load operation), the required flow rate is below the pump's minimum capacity. The necessary pump protection is achieved by routing the differential volume back into the feedwater tank or condenser via a pump bypass system—the minimum flow system featuring the minimum flow valve. Consequently, the minimum flow valve functions as a pump safety valve.
