Schroeder pump protection valves were recently selected by thyssenkrupp Steel Europe AG for the general overhaul of unit 4 of its power station “Hermann Wenzel”. In the previous system, valves from another manufacturer were installed, but these had repeatedly caused problems because the minimum flow control was carried out via two valves: on the one hand from a pulse generator (non-return valve on the pump discharge nozzle) and on the other hand from a minimum flow valve with adjusting piston and throttle.
So thyssenkrupp looked out for a better solution. The required valves had to have a nominal size of 125 mm (for the electric pumps) or 200 mm (for the turbopump) and a nominal pressure of PN 630 bar. The decision fell on the minimum flow system “SMA” by Schroeder Valves. These are high-pressure valves, which automatically protect centrifugal pumps against damage that may occur as a result of the partial evaporation of the pump content when the pumps are operated under low load. As soon as the main pump flow falls below a predetermined value, the valve opens the bypass and safely drains the minimum volume, even if the pumping volume in the main flow direction drops to zero.
“The SMA valve is a compact system that combines the performance formerly achieved by the two built-in valves,” says Poot. “A second valve is no longer necessary.” The Schroeder valves also convinced thyssenkrupp Steel Europe, because in other plants they have proven to be very reliable, durable and extremely low-maintenance due to their construction and the high-quality materials used.
Courtesy of Schroeder Valves.