Abstract: The invention relates to a sealing system, in particular for sealing pump shafts of vertically arranged pumps for conveying liquefied natural gas (LNG) or other cryogenic fluids below ?80° C. The sealing system has a mechanical seal arrangement. A barrier fluid flows through the mechanical seal arrangement at a barrier fluid pressure. The mechanical seal arrangement prevents a sealing fluid from exiting a sealing chamber. The barrier fluid pressure is higher than a sealing fluid pressure in the sealing chamber.

Abstract: The invention relates to a sealing system, in particular for sealing pump shafts of vertically arranged pumps for conveying for example liquefied natural gas (LNG) or other cryogenic fluids below ?80° C. The sealing system has a mechanical seal arrangement which is flowed through by a barrier fluid at a barrier fluid pressure. The mechanical seal arrangement prevents an exiting of a sealing fluid from a sealing chamber, wherein the barrier fluid pressure is higher than a sealing fluid in the sealing chamber. To allow a sealing system which can be manufactured inexpensively and is particularly simple to handle, it is proposed in accordance with the invention that a piston rod of a barrier fluid pressure device required for the setting of the barrier fluid pressure is arranged at least partly outside a cylinder. The cylinder can thus be made short and thus light weight and inexpensively.