Steam and condensate coupling for a drying cylinder in a paper machine

An arrangement for a drying cylinder in a paper machine, comprising

• a stationary steam and condensate coupling comprising a steam pipe structured and arranged to pass steam into a space inside a drying cylinder, and a condensate pipe structured and arranged to remove condensate from the interior space in the drying cylinder,
• a revolving axle for the drying cylinder, said steam and condensate pipes being passed through said axle,
• a stationary, non-revolving seal located between said axle and said coupling,
• said coupling further comprising
• a piston ring arranged to move along an axial direction of said steam and condensate pipes, said piston ring having a face placed substantially perpendicularly to said axial direction, and
• sealing means for pressing said seal against said axle, said piston ring and said seal being pressed toward said axle by a force produced by steam passed in said coupling onto said face of said piston ring, such that by means of the steam pressure, a pressure-tight joint is provided between said seal and said axle,
• a flange permanently connected to said axle, said seal being pressed against said flange part such that the pressure-tight joint is provided between said seal and said flange, and
• a rotatory support having an annular space therein, said piston ring comprising a piston part arranged to move in said annular space and said face of said piston ring being located on a projection part that projects from said piston part.