DB / DBW type of valves are overflow valves with 2 sections and concentric in structure used for pioneering control. Both pioneering valve and the main valve are of cone valve in structure. The inner chamber is made from casting, which features bigger flux capacity, simple in structure, low in noise, good in switching characteristic and stable in performance.

DB type of valves is mainly used in pressure part of the system, serving as overflow valve, safety valve or remote pressure control valve. DBW type of valves is extensively serving in fields of light industry, machine tool, metallurgy, mining and aerospace.