DB-DBW

Pressure valves of type DB and DBW are pilot-operated pressure relief valves. They are used for limiting (DB) or limiting and magnetically unloading (DBW) the operating pressure. The pressure relief valves (DB) basically consist of the main valve with main spool insert and pilot control valve with pressure adjustment element.

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The pressure applied to channel P acts on the main spool. At the same time, pressure is applied to the spring-loaded side of the main spool and to the ball in the pilot control valve via the control lines and which are equipped with nozzles and. If the pressure in channel P exceeds the value set at the spring, the ball opens against the spring. The signal for this is provided internally from channel P via control lines and The hydraulic fluid on the spring-loaded side of main spool now flows via the control line, nozzle bore and ball into the spring chamber.

From here, it is fed into the tank, either internally for type DB …– via control line), or externally for type DB…Y via control line. Nozzles and cause a pressure drop to occur at the main spool, hence the connection from channel P to channel T opens. The hydraulic fluid now flows from channel P to channel T, whilst the set operating pressure is maintained. The pressure relief valve can be unloaded or switched to another pressure (second pressure rating) via port X.