A method for the pressure regulation of a barrier fluid in a pumping device (10) is introduced, which includes a pump unit (11) with a shaft (12) and a pump housing (13), a drive unit (17), which is mechanically coupled to the pump unit and a shaft sealing arrangement (16.1, 16.2), which seals the pump housing (13) relative to the shaft (12). In the method, a pumping medium is pumped by means of the pumping device (10) and the barrier fluid is conveyed via a feed line (5.1, 5.2) to a common housing (18), in which the pump unit (11) and the drive unit (17) are arranged, in order to prevent a leakage of the pumping medium out of the pump housing (13). Additionally, the pressure of the supplied barrier fluid is increased when a pressure difference between the pressure of the supplied barrier fluid and a detected pressure of the pumping medium in the pump unit (11) falls below a pre-determined value. For this purpose a pressure reducing valve (1) for the differential-pressure is opened and the feed line is connected through to a source (3, 4) for the barrier fluid via the open valve, the pressure of which lies by more than the pre-determined value above the pressure of the pumping medium in the pump unit.