Leak-Free Load-Control Cartridge Valve, Size 6
Q
max
= 50l/min (13 gpm),p
max
= 420bar (6000 psi)
leak-proof, pilot operated, cartridge design
Series BBV 6 C-...
1/9
Reference: 300-P-9050008-EN-04
Issue: 08.2020
S Compact design for cavity type according to
Bucher standard – M42x1.5
S Two-stage load-control valve and bypass check valve
are functionally combined in one coaxial valve assembly
S Leak-free load holding
S The load pressure has very little influence on the pilot
pressure required → area ratio 1:66
S Guaranteed closing force for the load-control assembly
→ reliable shut-off even with a broken spring
S Thanks to the various pilot control styles, the valve can
always be adapted to the system requirements
S Hardened, ground and lapped seat valve components
ensure permanent leaktightness and long service life
S All external parts with zinc-nickel coating according to
DIN EN ISO 19598
1 Description
Leak-Free load-control valves in this series prevent hy
draulic actuators from running ahead of the available oil
supply. In one valve, they combine the functions of load-
holding, safety and pipe-rupture protection.
These hydraulic load-control cartridge valves from the se
ries BBV 6 C-… are size 6, pilot operated, high performance
screw-in cartridges with an M42x1.5 mounting thread. They
are ideally suited for use in high-pressure applications up to
420 bar (6000 psi). Thanks to the various pilot control vari
ants, the cartridge can be optimally adapted to the system
requirements. The compact design allows for minimum in
stallation space. All external parts of the cartridge are zinc-
nickel plated, and are thus suitable for use in the harshest
operating environments. The screw-in cartridges mainly
used in mobile and stationary applications (e.g. for speed
control of cylinders, hydraulic motors or on the luffing mech
anisms).
2 Symbol
A
B
X
300-P-9050008-EN-04/08.2020
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3 Technical data
General characteristics Description, value, unit
Designation leak-free load-control cartridge valve
Design leak-proof, hydraulically pilot operated, cartridge design
Size size 6
Mounting method screw-in cartridge – M42x1.5
Tightening torque 250Nm ± 10% (184.4 ft-lbs ± 10)
Main ports A, B
Control port X
Ø 8 mm (Ø .314 inch)
Ø 4 mm (Ø .157 inch)
Weight 0.7…0.8 kg (1.54…1.76 lbs)
Mounting attitude unrestricted
Ambient temperature range -25°C … +80°C (-13 °F … +176 °F)
(others on application)
Surface corrosion protection all external parts with zinc-nickel coating according to
DIN EN ISO 19598
Hydraulic characteristics Description, value, unit
Maximum operating pressure 420bar (6000 psi)
Maximum pressure at port B (static) 600bar (8700 psi)
Maximum flow rate 50 l/min (13 gpm)
Flow direction A → B, free flow through check valve
B → A, controlled flow
Operator type hydraulic proportional
Opening pilot ratio 1:66
Hydraulic fluid HL and HLP mineral oil to DIN 51 524;
for other fluids, please contact BUCHER
Hydraulic fluid temperature range -25°C … +80°C (-13 °F … +176 °F)
Temperature rating of seals NBR
FKM
MIL
-25°C … +100°C (-13 °F … +212 °F)
-20°C … +200°C (-4 °F … +392 °F)
-55°C … +80°C (-67 °F … +176 °F)
Viscosity range 2.8…1500 mm
2
/s (cSt), recommended 10…380 mm
2
/s (cSt)
Minimum fluid cleanliness
Cleanliness class to ISO 4406:1999
class 20/17/14
300-P-9050008-EN-04/08.2020
Series BBV
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4 Construction and function
4.1 Neutral position (load pressure at B, ports A and X depressurized)
In the neutral position, there is zero leakage from B → A. The valve is held closed by the check valve spring, which acts the
pilot valve ball and thus on the control spool, and also by the load pressure, which acts on the rear side of the pilot valve ball
and the control spool.
4.2 Check valve function (flow from A → B)
To raise the actuator, pump pressure is applied via port A to the valve seat area of the control spool and causes the control
spool together with the pilot ball to open, pushing against the check valve spring. Due to the small effective area of the pilot
ball, when the control spool moves in the opening direction during the check valve function the pilot ball moves with it, and
does not lift from its seat in the spool.
4.3 Lowering function (flow from B → A)
Initial decompression
The pilot pressure at port X moves the pilot piston in opposition to the pilot spring, lifting the pilot ball from its seat in the control
spool. The load pressure behind the control spool now decays as it escapes past the pilot ball seat to port A.
Opening the control spool
With further increase in the pilot pressure, the pilot piston compresses the pilot spring still more. It then makes direct contact
with the control spool and pushes it open aigainst the check valve spring.
The pilot pressure acting on the pilot piston therefore controls the open metering area of the control spool, and consequently
the flow rate from B → A.
Damping
The system can be protected against oscillations by using suitable damping orifices. The effect of the bypass orifice from
X → A is to make it necessary to use higher pilot pressures (pressure divider function) and this improves the damping
behaviour.
The orifices are protected against contamination by a mesh filter at port X and a check valve that prevents flow from A.
300-P-9050008-EN-04/08.2020
Series BBV
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5 Performance graphs
measured with oil viscosity 33mm
2
/s (cSt)
Δp = f (Q) Pressure drop - Flow rate characteristic
Check valve function, A → B
0
(140)
(285)
(430)
Q [l/min (gpm)]
50403020100
(570)
(700)
(13)(11)(8.0)(5.3)(2.6)
10
20
30
40
50
(860)60
P0051.ai
1
2
3
4
5
p = f (Q) Pressure - Flow rate characteristic
Pilot pressure pX @ 200 bar load pressure, B → A
(with damping orifice, without bypass orifice)
0
(140)
(285)
(430)
Q [l/min (gpm)]
50403020100
pX [bar (psi)]
(570)
(13)(11)(8.0)(5.3)(2.6)
10
20
30
40
P0053.ai
1
2
3
4
5
Δp = f (Q) Pressure drop - Flow rate characteristic
Lowering function, B → A, fully open
0
(285)
Q [l/min (gpm)]
50403020100
(570)
(13)(11)(8.0)(5.3)(2.6)
20
40
(860)60
(1150)80
(1400)100
P0052.ai
1
234
5
Legend:
(applies to all characteristic curves)
1 piston type 4SL
2 piston type 4FS
3 piston type 4FL
4 piston type 2FL
5 piston type 8FS
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5.1 Orifice names
A
B
X
1
2
1 damping orifice
2 bypass orifice
5.2 Table of opening pressures
Opening pressure at 200 bar load pressure (theoretical values).
pX
pre-opening
[bar / (psi)]
pX
start of opening
[bar / (psi)]
pX
fully open
[bar / (psi)]
Bypass orifice
[mm]
damping orifice
[mm]
9.0 / (130.5) 16.0 / (232.0) 33.0 / (478.6) Ø0.00 Ø0.25…0.40
12.0 / (174.0) 21.0 / (304.5) 45.0 / (652.6) Ø0.30 Ø0.40
14.0 / (203.0) 25.0 / (362.5) 52.5 / (761.4) Ø0.30 Ø0.35
14.0 / (203.0) 25.0 / (362.5) 54.0 / (783.2) Ø0.35 Ø0.40
18.0 / (261.0) 32.0 / (464.1) 67.5 / (979.0) Ø0.30 Ø0.30
18.0 / (261.0) 32.0 / (464.1) 67.5 / (979.0) Ø0.35 Ø0.35
18.0 / (261.0) 32.0 / (464.1) 67.5 / (979.0) Ø0.40 Ø0.40
23.0 / (333.5) 42.0 / (609.1) 88.5 / (1283.5) Ø0.45 Ø0.40
24.0 / (348.0) 43.0 / (623.6) 91.5 / (1327.0) Ø0.40 Ø0.35
26.0 / (377.0) 46.0 / (667.1) 97.5 / (1414.1) Ø0.35 Ø0.30
34.0 / (493.1) 60.0 / (870.2) 126.0 / (1827.4) Ø0.45 Ø0.35
37.0 / (536.6) 67.0 / (971.7) 141.0 / (2045.0) Ø0.40 Ø0.30
54.0 / (783.2) 97.0 / (1406.8) 205.5 / (2980.5) Ø0.45 Ø0.30
IMPORTANT!:
The opening pressure can be adjusted to the sys
tem by changing the orifices.
IMPORTANT!:
Further orifice combinations available in consulta
tion with Bucher Hydraulics.
300-P-9050008-EN-04/08.2020
Series BBV
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6 Dimensions & sectional view
Example for the dimensional units:
0.79 = 0.79mm [millimeter]
(.031) = 0.031“ [inch]
111.2
(4.37)
93.2
(3.66)
17
(.669)
10
(.393)
(Ø1.25)
300−4−10023104−−
Item Qty. Description
1 1 O-Ring ∅37.77x2.62
2 1 O-Ring ∅31.42x2.62
3 1 O-Ring ∅28.24 x 2.62
4 1 Backup ring ∅37.00/32.80 x 1.30
5 2 Backup ring ∅34.00/29.90 x 1.30
IMPORTANT!
Item No. 3000306312 = seal kit NBR (Nitril)
Item No. 3000307037 = seal kit FKM (Viton)
Item No. 3000306511 = seal kit MIL (low temp.)
7 Installation information
IMPORTANT!:
Designing load-control valves requires specialist
technical knowledge and product knowledge.
Safety applications must be verified by adequate
tests to ensure safety in actual use.
IMPORTANT!:
The valve may only be used for its intended pur
pose within its nominal rating. If you plan to use it
outside the nominal rating, you must contact the
valve manufacturer.
The ultimate responsibility for safety in the instal
lation and use rests with the end-machine manu
facturer of the mobile application.
IMPORTANT!
When fitting the cartridges, use the specified tigh
tening torque. No adjustments are necessary,
since the cartridges are set in the factory.
ATTENTION!
Only qualified 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 tho
roughly before fitting them.
ATTENTION!:
The valve may only be mounted or tightened
using the SW 46 hexagon!
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8 Application examples
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9 Ordering code
BBV = load control valve
6 = size 6
C = cartridge design
2FL = piston type 2FL
4FL = piston type 4FL
4FS = piston type 4FS
4SL = piston type 4SL
8FS = piston type 8FS
0.25 = damping orifice Ø0.25
0.30 = damping orifice Ø0.30
0.35 = damping orifice Ø0.35
0.40 = damping orifice Ø0.40
BY = with bypass (standard)
0.00 = bypass orifice Ø0.00 (closed)
0.30 = bypass orifice Ø0.30
0.35 = bypass orifice Ø0.35
0.40 = bypass orifice Ø0.40
0.45 = bypass orifice Ø0.45
N = NBR (Nitrile) seals (standard)
V = FKM (Viton) seals
T = MIL (low temperature) seals
(special seals - please contact BUCHER)
/N
e.g.
-BBV C6 0.00-
BY
/
0.30/2FL
IMPORTANT!:
Further orifice combinations available in consulta
tion with Bucher Hydraulics.
300-P-9050008-EN-04/08.2020
Series BBV
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10 Cartridge cavity
Ø 44.4
M42 x 1.5
Ø 37 H7
()
A
2.8
min. 17
25
min. 40 (Ø37 H7)
49
min. 66 (Ø34 H7)
min. 95
Ø 8Ø 8
Ø 4
21
45
min. 68
0
Ø 34 H7
()
gerundet, poliert
rounded, polished
X
X
A
B
wahlweise
optional
ATTENTION!
You must maintain the specified positional and
diametral tolerances. To ensure trouble-free ope
ration of the screw-in cartridges, we strongly re
commend that pilot drilling, boring, reaming and
cavity thread-cutting are always performed in one
setup.
E 2020 by Bucher Hydraulics AG, CH-6345 Neuheim
www.bucherhydraulics.cominfo.ch@bucherhydraulics.com
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.
Classification: 430.325.360.305.315.325.305.310