RINGO VALVULAS COMPLETES THE MANUFACTURING AND TESTIN OF SDV GATE VALVES IN SIZES 24” & 28” CLASS 600 LBS FOR DAELIM INDUSTRIAL CO. LTD. THE VALVES ARE PROVIDED WITH SINGLE ACTING LINEAR PNEUMATIC ACTUATORS WITH FAIL SAFE POSITION. THE OPERATION OF THIS TYPE OF VALVES, WHICH IS IN FACT VERY COMPLEX DUE TO THE VERY SHORT VALVE OPERATION TIMES, HAS BEEN SUCCESFULLY PROOVEN DURING THE FINAL ACCEPTANCE TESTS.