The invention relates to a flowmeter for regulating and monitoring the flow of sealing fluid to be conducted to a seal of a rotating shaft, the meter including a sealing fluid metering channel, a sealing fluid inlet, and a connection towards the seal for regulating the flow of sealing fluid, a non-return valve for preventing the sealing fluid from flowing back to the flowmeter, a regulating and monitoring mechanism, whereby the sealing fluid flows through the opening, and a cleaning mechanism, which is movable by an actuator. The non-return valve is arranged as an extension of the metering channel at the meter outlet side end, coaxially with the metering channel, whereby the metering cone is in mechanical contact with the non-return valve, and thus it is also possible to clean the non-return valve with the cleaning mechanism.