Abstract: A method and an apparatus for conditioning a dampening solution of a wet offset printing machine, include keeping constant or changing the hardness of the dampening solution added to a container during processing of a print job. The hardness of the dampening solution is determined by measuring the conductivity of the dampening solution and is converted into a hardness value according to a determined formula-based or table-based relationship between the hardness and the conductivity of the dampening solution. The change of the hardness of the dampening solution is compensated for during printing by replacing used or withdrawn dampening solution with dampening solution that has a lower or higher hardness, wherein the amount and/or the degree of hardness of the supplied dampening solution having lower or higher hardness is determined from the conductivity measurements and the formula-based or table-based relationship.

Abstract: The invention involves a printing press comprising a spray dampening unit 2 having a spray nozzle cleaning device 3, a spray dampening unit 2 having a spray nozzle cleaning device 3 and a spray nozzle bar 22 having a spray nozzle cleaning device 3. Said spray nozzle cleaning device 3, respectively, was produced with fluid nozzles 34 using a fluid line system 31, the use of a fluid line system with fluid nozzles to produce such a spray nozzle cleaning device and a procedure to clean the spray nozzles 23 of a spray dampening unit by means of such a spray nozzle cleaning device 3. Said spray nozzle cleaning device has been or can be assembled in a spray dampening unit, comprising a fluid line system 31 having several fluid nozzles 34 by means of which a cleaning fluid can be sprayed on the spray nozzles 23.

Abstract: Valve arrangement for spray damping units of printing machines with at least one valve for controlling a flow of liquid, in which the valve includes a housing with an inlet and outlet, into which a valve body arrangement is inserted with the help of a fast-action closure.

Abstract: The invention involves a printing press comprising a spray dampening unit 2 having a spray nozzle cleaning device 3, a spray dampening unit 2 having a spray nozzle cleaning device 3 and a spray nozzle bar 22 having a spray nozzle cleaning device 3. Said spray nozzle cleaning device 3, respectively, was produced with fluid nozzles 34 using a fluid line system 31, the use of a fluid line system with fluid nozzles to produce such a spray nozzle cleaning device and a procedure to clean the spray nozzles 23 of a spray dampening unit by means of such a spray nozzle cleaning device 3. Said spray nozzle cleaning device has been or can be assembled in a spray dampening unit, comprising a fluid line system 31 having several fluid nozzles 34 by means of which a cleaning fluid can be sprayed on the spray nozzles 23.

Abstract: A method for cleaning a process fluid for offset printing by transverse flow filtration, for which the process fluid, which is to be cleaned, flows over the surface (28) of a transverse flow filtration membrane (18), the flow being produced at least partly by a movement of the transverse flow filtration membrane (18) through the process fluid.

Abstract: Valve arrangement for spray damping units of printing machines with at least one valve for controlling a flow of liquid, in which the valve includes a housing with an inlet and outlet, into which a valve body arrangement is inserted with the help of a fast-action closure.

Abstract: A valve arrangement for spray dampening units on printing machines with a feeder system to supply the valve arrangement with pressurized dampening agent and spray nozzles downstream of the valve arrangement, includes two valves disposed behind each other with staggered opening times. In a first embodiment, the opening times are staggered so that both valves are only open at the same time for a small period of time. This means shorter effective opening times can be achieved than with individual valves. In a second embodiment there is an elastic buffer element between the two valves, and the opening times are completely staggered so that there are no common opening times. When the upstream valve is opened the buffer element generates an additional uptake of dampening agent, which is ejected by the buffer element when the first valve is closed and the downstream valve is opened.