Abstract: The barrel pump has a tubular pump housing and a rotor shaft which is supported by a support tube and, at its bottom end, bears an elastic cone which has a circumferential groove which interacts with the opening edge of an inlet in the manner of a snap-action closure when the rotor shaft is displaced in the direction of incoming flow with respect to the pump housing. The cone seal is situated in front of the inlet, as seen in the direction of flow. To displace the rotor shaft with respect to the pump housing, a rotary cap is provided above the outlet, pins of which cap engage in grooves of a groove flange which is screwed onto the pump housing, the grooves having a pitch, so that as a result of the rotary cap being turned relative displacement between rotor shaft and pump housing is brought about.

Abstract: A barrel pump has a main pump pipe set comprising an outer housing jacket and a supporting pipe received therein for a rotor shaft. Either a carrier part with an individual sliding ring seal or a carrier part which corresponds in its outer dimensions to the carrier part and has a leakage channel for ascending liquid can be screwed onto the lower end of this main pump pipe set. The rotor shaft projects beyond this main pipe pump set. It is also possible for a carrier part with a leakage channel and a double sliding ring seal arranged in the region of the leakage channel to be screwed on. Due to their identical outer dimensions, the carrier parts are interchangeable. A pump base which encloses the pump rotor and is fastened to the lower end of the rotor shaft can be attached to the lower end of each carrier part.