GEMÜ C58 is an ultra-pure 3/2-way process valve in order to change over between a supply and two outlets, whereby it can also be operated in the other flow direction. The switch position can be detected using an optical position indicator. The 3/2-way process valve is suitable for ultra-pure and corrosive media. All media wetted parts are made of pure and highly resistant PTFE. The 3/2-way process valve is therefore particularly suitable for applications in media supply or in the process area of semiconductor production.