Abstract: The invention relates to a sealing mechanism and to a method which forms the basis for the former and in which a clamping ring which loads a sealing element compensates for an operationally induced change in the volume which is available for the sealing element, as a result of which the sealing action of the sealing element can be maintained reliably even in the case of high operating pressures.

Abstract: A control arrangement for controlling a piston pump unit for liquid chromatography, in particular high-performance liquid chromatography, is described. The piston pump unit has at least two piston-cylinder units which operate cyclically in a phase-offset manner and generate, at an outlet port, a predetermined flow of a liquid medium to be delivered. A system pressure is established at the outlet port, irrespective of an associated fluid load resistance. The control arrangement is configured to record the pressure in the cylinder volume of at least a first of the at least two piston-cylinder units. During a measurement phase of the compression phase of the first piston-cylinder unit or during a measurement phase of the decompression phase of the first piston-cylinder unit, the control arrangement stops the drive device for the first piston-cylinder unit for a predetermined time period and in the process records measurement data which characterize the time profile of the pressure.

Abstract: Methods of volume measurement of a liquid are described. During extraction or feed of the liquid, at least two time points of the altered volume of the liquid is measured. Respective hydrostatic pressures are measured at these time points. The pressure difference is determined and the current volume of the liquid present in the container is determined.

Abstract: A switching valve, in particular for controlling a fluid subject to high pressure is described. The switching valve has at least one valve unit, which includes a valve seat element and a switching element guided movably in a guide element, wherein the valve seat element and the switching element interact to provide a switching valve function. The valve seat element and the guide element are provided in a housing. The valve seat element, the guide element and the housing form a through flow channel for the fluid to be controlled. An elastically and/or plastically deformable sealing body is provided in a fully enclosed space between the inner wall of the housing and the outer walls of the valve seat element and of the guide element. The sealing body can be subject to a predetermined pressure to seal off the through flow channel from the housing and subject the valve seat element and the guide element to an inward-directed preload.

Abstract: The invention relates to a sealing mechanism and to a method which forms the basis for the former and in which a clamping ring which loads a sealing element compensates for an operationally induced change in the volume which is available for the sealing element, as a result of which the sealing action of the sealing element can be maintained reliably even in the case of high operating pressures.

Abstract: The invention relates to a part for a component for high-pressure liquid chromatography (HPLC), in particular a pump head for an HPLC pump, in which the strength has been increased by autofrettage and which consists of a material which is essentially chemically inert to the fluids used in HPLC. The invention further relates to an HPLC pump having a pump head which is configured as such a part.

Abstract: A control arrangement for controlling a piston pump unit for liquid chromatography, in particular high-performance liquid chromatography, is described. The piston pump unit has at least two piston-cylinder units which operate cyclically in a phase-offset manner and generate, at an outlet port, a predetermined flow of a liquid medium to be delivered. A system pressure is established at the outlet port, irrespective of an associated fluid load resistance. The control arrangement is configured to record the pressure in the cylinder volume of at least a first of the at least two piston-cylinder units. During a measurement phase of the compression phase of the first piston-cylinder unit or during a measurement phase of the decompression phase of the first piston-cylinder unit, the control arrangement stops the drive device for the first piston-cylinder unit for a predetermined time period and in the process records measurement data which characterize the time profile of the pressure.

Abstract: Methods of volume measurement of a liquid are described. During extraction or feed of the liquid, at least two time points of the altered volume of the liquid is measured. Respective hydrostatic pressures are measured at these time points. The pressure difference is determined and the current volume of the liquid present in the container is determined.

Abstract: A switching valve, in particular for controlling a fluid subject to high pressure is described. The switching valve has at least one valve unit, which includes a valve seat element and a switching element guided movably in a guide element, wherein the valve seat element and the switching element interact to provide a switching valve function. The valve seat element and the guide element are provided in a housing. The valve seat element, the guide element and the housing form a through flow channel for the fluid to be controlled. An elastically and/or plastically deformable sealing body is provided in a fully enclosed space between the inner wall of the housing and the outer walls of the valve seat element and of the guide element. The sealing body can be subject to a predetermined pressure to seal off the through flow channel from the housing and subject the valve seat element and the guide element to an inward-directed preload.

Abstract: The invention relates to a fixing system for at least one fluidic component (4) of a chromatography device, particularly for fastening the at least one fluidic component (4) in a column oven, where at least one clasp (2) is provided, on which at least one fixing element (3) can be fixed in a detachable way in a desired position within a fixing area (2e) of the clasp (2) by friction or positive locking, where the at least one clasp (2) is fixed by means of one or more carrier elements (1) in a predetermined position, and where the at least one fixing element (3) is configured for receiving and fastening the at least one fluidic component (4).