Production and rehabilitation of runners

TEKUM has successfully fabricated several runner assemblies for Francis and Kaplan turbines. Notably, the focus was on the manufacturing, with an emphasis on welding and testing of the welds between the blades, crown, and band for two Francis runner assemblies for a 70MW turbine, where each runner assembly weighed 88 tons, had an outer diameter of 5600mm, and a height of 2700mm. The material used for the runner was GX4CrNi 13-4 + QT1. Before the welding commenced, TEKUM prepared the following documentation: 2 welding procedure certificates for 138 MC filler material, the technological procedure and sequence of welding, welder qualifications, WPSs, welding book, certification of welding equipment and preheating devices, etc. The scope of testing after PWHT included: 100% PT (Positive Testing), 100% MT (Magnetic Testing), 100% UT (Ultrasonic Testing), and 100% VT (Visual Testing).