Functional description of Pressure reducing valve direct operated
The pressure reducing valve type ZDR 10 D.. is a 3-way direct operated valve of sandwich plate design with a pressure relief function on the secondary side. It is used to reduce the system pressure.
The pressure reducing valve basically consists of the housing (1), the control spool (2), a compression spring (3),and the adjustment (4) as well as an optional check valve. The secondary pressure is set by the pressure adjustment element (4).
Model "DA"
At rest, the valve is normally open, and fluid can flow unhindered from port A to port A1. The pressure in port A1 is at the same time via the control line (5) present at the spool area opposite to the compression spring (3). When the pressure in port A1 exceeds the pressure level set at the compression spring (3), the control spool (2) moves into the control position against the compression spring (3) and holds the set pressure in port A1 constant. The control pressure and pilot oil are taken from port A1 via control line (5).
If the pressure in port A1 rises still further due to external forces, the
control spool (2) is moved still further towards the compression
spring (3).
This causes a flow path to be opened at port A1 via control land (6) on the control spool (2) and housing (1) to tank (port TB). Sufficient fluid then flows to tank to prevent any further rise in
pressure. The spring chamber (7) is always drained to tank externally via port TA .
A pressure gauge connection (8) permits the secondary pressure at the valve to be monitored. It is only possible to fit a check valve for free flow in ports A1 to A in version "DA".
Models "DP" and "DB"
In model "DP", the pressure is reduced in port P1. The control pressure and the pilot oil is taken internally from port P1. In model "DB", the pressure in port P1 is reduced, and the pilot oil taken from port B.
Attention!
When the directional valve is in the switched position P to A, pressure in port B must not exceed the set secondary pressure. Otherwise, pressure in port A will be reduced. If used without a directional valve, TA and TB must be interconnected (e.g. in the cover plate).
Features of Pressure reducing valve with sandwich plate:
- Sandwich plate design
- Pressure reduction in ports A, B or P
- 3 adjustment elements:
. Rotary knob
. Hex. head screw with protective cap
. Lockable rotary knob with scale
- 4 pressure ratings
- Check valve, optional
Section of Pressure reducing valve direct operated
Symbol
Ordering details:
Technical data:
Unit dimensions (dimensions in mm)
ZDR10DA or ZDR10DP
Section of Pressure reducing valve direct operated
Symbol
Ordering details:
Technical data:
Weight (kg) | Approx.2.8 |
Pressure Fluid | Mineral oil or Phospate ester |
Temperature range ℃ | -20~+80 |
Viscosity range mm²/s | 10~800 |
Degree of fluid contamination Mpa | Max. permissible Degree of fluid contamination is to NAS 1638, class 9β10≥75 |
Max. operating pressure(inlet) Mpa | 31.5 |
Secondary pressure Mpa | To 21 |
Back pressure Mpa | To 15 |
Max. flow L/min | 50 |
Unit dimensions (dimensions in mm)
ZDR10DA or ZDR10DP
