Restrained socket pipe systems are an economical solution for industrial pipelines and urban pipe installations. They are characterized by an extended flexibility of the socket-spigot connections that definitely simplifies pipe routing. These pipes are very easy to install without any welding or other preliminary actions. Especially cast iron pipes made distinct progresses in the last years. Material development has born cast iron based materials with steel like properties. They withstand pressures of more than 150 bar, are suitable even for chemically aggressive and mechanically abrasive media, and are available with heavy corrosion protection. These systems are a good choice for installations which are located in regions suffering from earthquakes or other movements of the soil like in open pit and below ground mines. Moreover the very easy connection and disconnection of the BLS junction make restrained cast iron socket pipes predestinated for temporary pipe installations or installations located in areas, which are difficult to access and where material handling is difficult and welding is almost impossible under economic conditions. That’s why penstocks for water power plants nowadays are realized with cast iron socket pipe systems.