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Pressure Relief Valve
Poppet Type, Direct-Acting
with Atmospheric Relief
Metric Cartridge – 350 bar
DB4E-25X
Up to 30 l/min
Up to 350 bar
The pressure relief valve DB4E-25X is a
direct-acting, spring-loaded poppet valve
with atmospheric relief.The spring exerts a
force on the poppet and presses it on the
valve seat. On the opposite side, the system
pressure exerts force on port 1 of the valve.
If the hydraulic pressure is below the pre-set
spring tension, the valve is closed. When
the hydraulic force exceeds the pre-set
spring tension the valve opens and allows
ow to tank via port 2. This continues until
the system pressure is equal to the spring
tension and the valve closes again.
The pressures at port 2 have practically no
effect on the opening pressure as the valve is
vented to atmosphere in the spring chamber.
To ensure that stable operation is maintained,
the poppet is securely located in the damping
piston which produces a damping force,
opposing the direction of movement, and this
has a stabilizing effect.
FEATURES
z Excellent stability throughout ow range
z Low hysteresis and accurate pressure control
z External surfaces zinc-plated and corrosion-proof
z Hardened and ground valve components to ensure minimal wear and extended
service life
z Adjustable throughout ow range
z Various pressure ranges up to 350 bar
z Pressure-resistant up to 350 bar at port 2
FUNCTION
SPECIFICATIONS
Operating pressure: max. 350 bar
Nominal ow: 30 l/min
Pressure setting ranges: 20 to 350 bar
Leakage: leakage-free
(max. 5 drops
≙ 0,25 cm³/min at 350 bar)
Media operating temperature range: min. -20 °C to max. +120 °C
Ambient temperature range: min. -20 °C to max. +120 °C
Operating uid: Hydraulic oil to DIN 51524 Part 1 and 2
Viscosity range: min. 7.4 mm²/s to max. 420 mm²/s
Filtration: Class 21/19/16 according to ISO 4406 or
cleaner
MTTF
d
: 150 years (see "Conditions and
instructions for valves" in brochure 5.300)
Installation: No orientation restrictions
Materials: Valve body: high tensile steel
Piston: hardened and
ground steel
Seals: FKM (standard)
NBR (optional, media
temperature range
-30 °C to +100 °C)
Seal ring: PU
Cavity: 06020
Weight: 0.24 kg
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MODEL CODE
DB4E – 25 X – 350 F 315
Basic model
Pressure relief valve, metric
Type
25 = standard with atmospheric relief
Series
(determined by manufacturer)
Pressure setting range
350 = up to 350 bar
Other pressure ranges on request
Type of adjustment
V = Allen head (standard)
F = xed setting, cannot be adjusted
P = can be lead-sealed, adjustable with tool
M = maximum pressure relief, adjustable with tool
Other types of adjustment on request
Opening pressure setting
No details = no setting, spring relaxed
315 = opening pressure in bar, factory pre-set,
Setting on request
PERFORMANCE
p
o
= 100 bar, tank pressure = 100 bar, ν = 33 mm²/s
p [bar]
p
o
= 200 bar, tank pressure = 200 bar, ν = 33 mm²/s
p [bar]
p
o
= 250 bar, tank pressure = 250 bar, ν = 33 mm²/s
p [bar]
p
o
= 350 bar, tank pressure = 350 bar, ν = 33 mm²/s
p [bar]
Q [l/min]
Q [l/min]
Q [l/min]
Q [l/min]
Standard models
Code Part No.
DB4E-25X-350V 3475344
Other models on request
Standard in-line bodies
Code Part No. Material Ports Pressure
R06020-01X-01 275266
Steel, zinc-
plated
G 3/8 420 bar
Other line bodies on request
p/Q
p/Q
p/Q
p/Q
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millimeter
subject to technical modications
CAVITY
06020
SW 13
torque
8
+2
Nm
SW 21
torque
45
+5
Nm
SW 13
torque
8
+2
Nm
SW 13
torque
8
+2
Nm
SW 13
int. hex. SW 4
Millimeter
Subject to technical modications
Millimeter
Subject to technical modications
Form tools
Tool Part No.
Countersink 170033
Reamer 1000768
Tap 1002648
Plug gauge 168840
DIMENSIONS
Adjustment type F Adjustment type V Adjustment type P Adjustment type M
HYDAC Fluidtechnik GmbH
Justus-von-Liebig-Str.
D-66280 Sulzbach/Saar
Tel: 0 68 97 / 509-01
Fax: 0 68 97 / 509-598
E-Mail: utec@hydac.com
NOTE
The information in this brochure relates to
the operating conditions and applications
described.
For applications or operating conditions
not described, please contact the relevant
technical department.
Subject to technical modications.
tting depth
max.
max.
max.
max.
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