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Type series: WDTUVB-_-16…
Reference: 400-P-170101-EN-02/08.2023
- Screw-in cartridge valve
- For cavity KTU
- All external parts with zinc-nickel plating according to
DIN EN ISO 19598
- Temperature-dependent bypass control
- Oil warms up rapidly (cold-start phase)
- Direct-mounted in coolers or manifold blocks
- Installation in threaded port body type GEUA
- Low head loss
- Choice of various pressure settings
- Extremely reliable
- Very stable operation
Directional valve
Bypass thermostat valve
Q
max
= 300 l/min, p
max
= 50 bar
mechanically with thermostat element, integral relief function
Type series: WDTUVB-_-16…
Description
These direct acting bypass thermostat valves are
size 16, temperature controlled, high performance
screw-in valves with an M33×1.5 mounting thread.
They are intended to be installed directly in coolers or
line-mounting body. Depending on the temperature
of the oil, they route the ow either straight to tank or
through the cooler. When the oil is cold (< 50 °C), the
connection P to T is open (bypass), which means that
the ow is directed to tank with minimal headloss and
the oil warms up rapidly. After the changeover tem-
perature is reached (> 65 °C), the integral thermostat
element closes the connection P to T. The valve now
directs the oil ow through the cooler. With an inte-
gral pressure-relief function, the bypass thermostat
valve also safeguards the cooler by protecting it from
any pressure peaks that may result from excessive
ow rates. The maximum pressure is determined by
the model that is selected. The valves are predomi-
nantly used in coolers in mobile as well as industrial
applications. All external parts of the screw-in valves
are zinc-nickel plated and are thus suitable for use in
the harshest operating environments.
Symbol
s
P
T
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Type series: WDTUVB-_-16…
Reference: 400-P-170101-EN-02/08.2023
Technical data
General characteristics Description, value, unit
Sales category minimum order quantity required (see order details)
Function group Directional valve
Function Bypass thermostat valve
Design Screw-in cartridge valve
Controls mechanically with thermostat element
Characteristic integral relief function
Construction size NG 16
Thread size M33×1,5
Mounting attitude horizontal
Weight 0,6 kg
Cavity acc. factory standard For cavity KTU
Tightening torque steel 60 Nm
Tightening torque aluminium 60 Nm
Tightening torque tolerance ± 10 %
Minimum ambient temperature - 30 °C
Maximum ambient temperature + 90 °C
Surface protection
All external parts with zinc-nickel plating according to
DIN EN ISO 19598
Sealing material see ordering code
Hydraulic characteristics Description, value, unit
Maximum operating pressure 50 bar
Maximum ow rate 300 l/min
Temperature for start of control action 50 °C
Flow direction see symbol
Hydraulic uid
HL and HLP mineral oil according to DIN 51 524; other uids
on request!
Minimum uid temperature - 30 °C
Maximum uid temperature + 90 °C
Viscosity range 10 … 650 mm²/s (cSt)
Recommended viscosity range 15 … 250 mm²/s (cSt)
Minimum uid cleanliness (cleanlineless class according to ISO
4406:1999)
class 20/18/15
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Type series: WDTUVB-_-16…
Reference: 400-P-170101-EN-02/08.2023
Performance graphs
measured with oil viscosity 33.0 mm²/s (cSt)
Δp = f (T) Pressure drop-temperature Δp = f (Q) Pressure drop-ow rate characteristic
0
2 (30)
4 (60)
6 (85)
8 (120)
10 (140)
T [°C (°F)]
60 70 8050403020100
9 bar (130 psi)
Q = 20 l/min (5 gpm)
9 bar (130 psi)
Q = 20 l/min (5 gpm)
(140) (158)
(176)
(122)(104)(86)(68)(50)
1)1)
400-PG-0099
p [bar (psi)]∆
9 bar (130 psi)
1) T = 70 °C (158 °F)
2) T = < 50 °C (122 °F)
9 bar (130 psi)
1) T = 70 °C (158 °F)
2) T = < 50 °C (122 °F)
400-PG-0100
0
5 (70)
10 (140)
15 (215)
20 (285)
Q [l/min (gpm)]
300
250200150100500
p [bar (psi)]∆
1)1)
2)
2)
300
25020015010050
Δp = f (T) Pressure drop-temperature Δp = f (Q) Pressure drop-ow rate characteristic
400-PG-0108
0
1 (15)
2 (30)
3 (40)
4 (60)
5 (70)
6 (85)
p [bar (psi)]∆
1)1)
T [°C (°F)]
60 70 8050403020100
6 bar (85 psi)
Q = 20 l/min (5 gpm)
6 bar (85 psi)
Q = 20 l/min (5 gpm)
(140) (158)
(176)
(122)(104)(86)(68)(50)
400-PG-0110
0
3 (40)
6 (85)
9 (130)
12 (170)
15 (215)
18 (260)
p [bar (psi)]∆
1)1)
2)
2)
6 bar (85 psi)
1) T = 70 °C (158 °F)
2) T = < 50 °C (122 °F)
6 bar (85 psi)
1) T = 70 °C (158 °F)
2) T = < 50 °C (122 °F)
Q [l/min (gpm)]
300250200150100500
30025020015010050
Δp = f (T) Pressure drop-temperature Δp = f (Q) Pressure drop-ow rate characteristic
400-PG-0421
0
1 (15)
2 (30)
3 (40)
4 (60)
p [bar (psi)]∆
1)1)
T [°C (°F)]
60 70 8050403020100
3 bar (40 psi)
Q = 20 l/min (5 gpm)
3 bar (40 psi)
Q = 20 l/min (5 gpm)
(140) (158)
(176)
(122)(104)(86)(68)(50)
400-PG-0422
0
2.5 (35)
5 (70)
7.5 (105)
10 (140)
p [bar (psi)]∆
1)1)
2)
2)
3 bar (40 psi)
1) T = 70 °C (158 °F)
2) T = < 50 °C (122 °F)
3 bar (40 psi)
1) T = 70 °C (158 °F)
2) T = < 50 °C (122 °F)
Q [l/min (gpm)]
300
250200150100500
300
25020015010050
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Type series: WDTUVB-_-16…
Reference: 400-P-170101-EN-02/08.2023
Δp = f (T) Pressure drop-temperature Δp = f (Q) Pressure drop-ow rate characteristic
400-PG-0109
0
0.5 (7.1
)
1 (15)
1.5 (20)
2 (30)
2.5 (35)
3 (40)
p [bar (psi)]∆
1)1)
T [°C (°F)]
60 70 8050403020100
2 bar (30 psi)
Q = 20 l/min (5 gpm)
2 bar (30 psi)
Q = 20 l/min (5 gpm)
(140) (158)
(176)
(122)(104)(86)(68)(50)
400-PG-0111
0
2 (30)
4 (60)
6 (85)
1)1)
2)
2)
2 bar (30psi)
1) T = 70 °C (158 °F)
2) T = < 50 °C (122 °F)
2 bar (30psi)
1) T = 70 °C (158 °F)
2) T = < 50 °C (122 °F)
250200150100500
25020015010050
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Type series: WDTUVB-_-16…
Reference: 400-P-170101-EN-02/08.2023
Dimensions and sectional view
Beispiel für die Masseinheit:
Example for the dimensional units:
0.79 = 0.79 mm millimeter
Thermoelement < 50 °C – Verbindung P nach T offen/
Thermostat element < 50 °C – connection P to T open
0[





Ø34.65×1.78
M
A = 1)
P
T
P
T
Thermoelement > 65 °C – Verbindung P nach T geschlossen/
Thermostat element > 65 °C – connection P to T closed
+1%5
Installation information
IMPORTANT!
1) When tting the screw-in cartridge valve,
use the specied tightening torque. The value
can be found in the chapter "Technical data".
ATTENTION!
Only qualied personnel with mechanical
skills may carry out any maintenance work.
Generally, the only work that should ever be
undertaken is to check, and possibly replace,
the seals. When changing seals, oil or grease
the new seals thoroughly before tting them.
IMPORTANT!
Other mounting position and the axial inci-
dent ow from port P to valve spool results in
other Dp-values.
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Type series: WDTUVB-_-16…
Reference: 400-P-170101-EN-02/08.2023
Application examples
V
2
V
1
WDTUV...
s
T
P
Manifold block with integral
cooler-bypass thermostat valve
Ordering code
W=
directional valve, cartridge construction
D=
direct acting
T=
temperature-actuated (thermostat element)
UV
=pressure-relief function is incorporated
B ...
Q=standard model - see relevant data sheets
Z ...
R=special features - please consult BUCHER
…=
for other response temperatures, please consult BUCHER
90
=pressure setting p
max
= 9 bar
60
=pressure setting p
max
= 6 bar
30
=pressure setting p
max
= 3 bar
20
=pressure setting p
max
= 2 bar
16
= size 16
J=
HNBR seals (standard)
(special seals - please contact BUCHER)
1 ...
9=design stage (omit when ordering)
-
Ex.
J16BTD UV - 50 - 90 -W 1
IMPORTANT!
Minimum order quantity of 500 pcs./year
50
=response temperature for thermostat ~ 50 °C
Related data sheets
Reference Description
400-P-040011 Form tools
400-P-080141 Cavity KTU
400-P-750151 Threaded port body GEUA
info.ch@bucherhydraulics.com www.bucherhydraulics.com
© 2023 by Bucher Hydraulics AG Frutigen, 3714 Frutigen, Switzerland
All rights reserved.
Data is provided for the purpose of product description only, and must not be construed as warranted characteristics in the legal sense. The
information does not relieve users from the duty of conducting their own evaluations and tests. Because the products are subject to continual
improvement, we reserve the right to amend the product specifications contained in this catalogue.