A pressure compensating device or arrangement for a roller arrangement which includes a central, non-rotating shaft provided with spaced apart bearings positioned adjacent opposite axial ends of the shaft and rotatably supporting at least one tubular roller segment, and where sealing arrangements are provided outside the bearings for sealing off the space inside the bearings and between the shaft and the roller segment towards the environment. The pressure compensating device includes a longitudinal bore extending from one end of the shaft and through at least a part thereof, with the bore communicating with the space between the sealing arrangements via channels. The bore is provided with a flexible member preventing direct communication between the exterior and the space between the sealing arrangements.