Pilot operated pressure relief valve, types ZDB/Z2DB 10V..L4X

Function and configuration

Pressure relief valve types ZDB and Z2DB are pilot operated and sandwich structure. They are used to limit the pressure in a hydraulic system.

They basically consist of the housing (7), together with one or two pressure relief valves cartridges. And the system pressure is set by means of relief valve(4).

At static position, the valves are closed. Pressure in port A acts on the spool (1). Pressure fluid flows through orifice (2) to the spring loaded side of the spool (1) and through orifice (3) to the pilot poppet (6). If the pressure in port A rises beyond the value setting at spring (5), the pilot poppet (6) opens. Fluid can flow from the spring loaded side of spool (1), orifice (3), and channel (8) into port T. The pressure drop moves spool (1) to open the connection from A to T, while the setting pressure at spring (5) is maintained. Pilot oil returns from the two spring chambers via port T externally.

Type ZDB10VA2-L4X/...

Notes:

The pilot relief valves have more internal leakage, If lower leakage is demanded, such as safety valve, it is recommended to choose direct operated pressure relief valves, ZDBD type.

Symbols

Ordering code

Technical data

Characteristic curves(Measured at oil =40°C +5°C, using HLP46)

Unit dimensions

Unit dimensions

Unit dimensions