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Hydraulic
Bladder Accumulator
Standard
1. DESCRIPTION
1.1. FUNCTION
Fluids are practically incompressible and
cannot therefore store pressure energy.
The compressibility of a gas is utilised in
hydraulic accumulators for storing uids.
HYDAC bladder accumulators are based
on this principle, using nitrogen as the
compressible medium.
A bladder accumulator consists of a uid
section and a gas section with the bladder
acting as the gas-proof screen.
The uid around the bladder is connected
to the hydraulic circuit so that the
bladder accumulator draws in uid when
the pressure increases and the gas is
compressed.
When the pressure drops, the compressed
gas expands and forces the stored uid
into the circuit.
HYDAC bladder accumulators can be used
in a wide variety of applications, some of
which are listed below:
energy storage z
emergency operation z
force equilibrium z
leakage compensation z
volume compensation z
shock absorption z
vehicle suspension z
pulsation damping z
See catalogue section:
Hydraulic Dampers z
No. 3.701
1.2. DESIGN
seal cap
lock nut
shell
gas valve
valve protection
cap
bladder
spacer
anti-extrusion
ring
seal ring
lock nut
oil valve
vent screw
1.2.1 Design
Standard Bladder Accumulator z
SB330/400/500/550
HYDAC standard bladder accumulators
consist of the pressure vessel, the
exible bladder with gas valve and the
hydraulic connecction with check valve.
The pressure vessel is seamless and
manufactured from high tensile steel.
Bladder accumulator z
SB330N
The ow optimised design of the
standard oil valve enables the maximum
possible operating uid ow rate to
increase to 25 l/s on this accumulator
type.
High Flow bladder accumulator z
SB330H
HYDAC high ow bladder accumulators,
type SB330H, are high performance
accumulators with a ow rate of up to
30 l/s. The uid connection is enlarged to
allow higher ow rates.
1.2.2 Bladder material
The following elastomers are available as
standard:
NBR (acrylonitrile butadiene rubber, z
Perbunan),
IIR (butyl rubber), z
FKM (uoro rubber, Viton z
®
),
ECO (ethylene oxide epichlorohydrin z
rubber).
The material must be selected according
to the particular operating uid and
temperature.
When choosing the elastomer, allowances
must be made for the fact that the gas
can cool down to below the permitted
elastomer temperature if there are adverse
discharge conditions (high pressure ratio
p
2
/p
0
, high discharging velocity). This can
cause cold cracking in the elastomer.
The gas temperature can be calculated
using the HYDAC Accumulator Simulation
Program ASP.
1.2.3 Corrosion protection
For operation with chemically aggressive
media, the accumulator shell can be
supplied with corrosion protection, such as
plastic coating on the inside or chemical
nickel-plating. If this is insufcient, then
stainless steel accumulators must be used.
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1.3. MOUNTING POSITION
HYDAC bladder accumulators can be
installed vertically, horizontally and at a
slant. When installing vertically or at a
slant, the oil valve must be at the bottom.
On certain applications listed below,
particular positions are preferable:
Energy storage: z
vertical,
Pulsation damping: z
any position from horizontal to vertical,
Maintaining constant pressure: z
any position from horizontal to vertical,
Volume compensation: z
vertical.
If the mounting position is horizontal
or at a slant, the effective volume and
the maximum permitted ow rate of the
operating uid are reduced.
1.4. TYPE OF MOUNTING
By using an appropriate adapter, HYDAC
accumulators, up to size 1 l, can be
mounted directly inline.
For strong vibrations and volumes above
1 l, we recommend the use of HYDAC
accumulator supports or the HYDAC
accumulator mounting set.
See catalogue sections:
Supports for Hydraulic Accumulators z
No. 3.502
ACCUSET SB z
No. 3.503
2. TECHNICAL
SPECIFICATIONS
2.1. EXPLANATORY
NOTES
2.1.1 Operating pressure
See tables
(may differ from nominal pressure for
foreign test certicates)
2.1.2 Nominal volume
See tables
2.1.3 Effective gas volume
See tables
based on nominal dimensions, this differs
slightly from the nominal volume and must
be used when calculating the effective
volume.
2.1.4 Effective volume
Volume of uid which is available between
the operating pressures p
2
and p
1
.
2.1.5 Max.owrateofoperatinguid
In order to achieve the max. ow rate given
in the tables, the accumulator must be
mounted vertically. It must be remembered
that a residual uid volume of approx. 10%
of the effective gas volume remains in the
accumulator.
2.1.6 Fluids
The following sealing and bladder
materials are suitable for the uids listed
below.
Material Fluids
NBR20 Mineral oils (HL, HLP,
HFA, HFB, HFC), water
ECO Mineral oil
IIR Phosphate ester
FKM Chlorinated hydro-
carbons, petrol
2.1.7 Permitted operating temperature
The permitted operating temperatures are
dependent on the application limits of the
metallic materials and the bladders.
The standard valve bodies, gas valves
and accumulator shells are suitable for
temperatures from -10 °C ... +80 °C.
Outside these temperatures, special
material combinations must be used.
The following table shows the correlation
between bladder material and application
temperature.
Material Temperature ranges
NBR20 -15 °C ... + 80 °C
NBR21 -50 °C ... + 80 °C
NBR22 -30 °C ... + 80 °C
ECO -30 °C ... +120 °C
IIR -40 °C ... +100 °C
FKM -10 °C ... +150 °C
2.1.8 Gas charging
Always only charge with nitrogen class 4.5,
ltered to < 3 µm.
If other gases are to be used, please
contact HYDAC for advice.
Hydraulic accumulators must only be
charged with nitrogen.
Never use other gases.
Risk of explosion!
2.1.9 Limits for gas pre-charge
pressure
p
0
≤ 0.9 • p1
with a permitted pressure ratio of:
p
2
: p
0
≤ 4 : 1
p
2
= max. operating pressure
p
0
= gas pre-charge pressure
2.1.10 Certicatecodes
China A9
EU member states U
1)
Japan P
Canada S1
2)
Switzerland U
USA S
others on request
1)
Alternative certicates possible
2)
Approval required in the individual provinces
On no account must any welding, soldering
or mechanical work be carried out on the
accumulator shell. After the hydraulic line
has been connected it must be completely
vented.
Work on systems with hydraulic
accumulators (repairs, connecting
pressure gauges etc) must only be carried
out once the pressure and the uid have
been released.
Please read the operating manual!
No. 3.201.CE
Note:
Application examples, accumulator sizing
and extracts from approvals regulations on
hydraulic accumulators can be found in the
following catalogue section:
Accumulators z
No. 3.000
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2.2. MODEL CODE
(also order example)
SB330 H – 32 A 1 / 112 U – 330 A 050
Series
Type
H = high ow
N = increased ow, standard oil valve dimensions
A = shock absorber
P = pulsation damper
S = suction ow stabiliser
B = bladder top-repairable
Combinations possible, e.g. HB - High ow with a top-repairable bladder
PH - pulsation damper with high ow rate.
No details = standard
Nominal volume [l]
Fluid connection
A = standard connection, thread with internal seal face
F = ange connection
C = valve mounting with screws on underside
E = sealing surfaces on front interface (e.g. on thread M50x1.5 - valve)
G = male thread
S = special connection, to customer specication
Gas side
1 = standard model
4)
2 = back-up model
3 = gas valve 7/8-14UNF with M8 female thread
4 = 5/8" gas valve
5 = gas valve M50x1.5 in accumulators smaller than 50 l
6 = 7/8-14UNF gas valve
7 = M28x1.5 gas valve
8 = M16x1.5 gas valve
9 = special gas valve, to customer specication
Material code
1)
Standard model = 112 for mineral oil
Depending on operating uid
others on request
Fluid connection
1 = carbon steel
2 = high tensile steel
3 = stainless steel
3)
6 = low temperature steel
Accumulator shell
0 = plastic coated (internally)
1 = carbon steel
2 = chemically nickel-plated (internal coating)
4 = stainless steel
3)
6 = low temperature steel
Accumulator bladder
2)
2 = NBR20
3 = ECO
4 = IIR (butyl)
5 = NBR21 (low temperature)
6 = FKM
7 = other
9 = NBR22
Certicationcode
U = PED 97/23/EC
Permitted operating pressure [bar]
Connection
Thread, codes for uid connections: A, C, E, G
A = Thread to ISO 228 (BSP)
B = Thread to DIN 13 or ISO 965/1 (metric)
C = Thread to ANSI B1.1 (UN..-2B seal SAE J 514)
D = Thread to ANSI B1.20.1 (NPT)
S = special thread, to customer specication
Flange, codes for uid connection: F
A = DIN ange
B = ange ANSI B16.5
C = SAE ange 3000 psi
D = SAE ange 6000 psi
S = special ange, to customer specication
Pre-charge pressure p
0
[bar] at 20 °C must be stated separately, if required!
1)
Not all combinations are possible
2)
When ordering spare bladders, please state smallest bladder connection port size
3)
Depending on type and pressure rating
4)
Gas valve type in SB < 50 l = 7/8 - 14 UNF, in SB ≥ 50 l = M50x1.5
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3. DIMENSIONS AND SPARE PARTS
3.1. DIMENSIONS
Dimensions
adapter
for
special
threads
Nominal volumes
Valve
Max. operating pressure
(PED 97/23/EC)
Effective gas volume
Weight
A
max.
B C Ø D
max.
J
thread
Ø E SW Q
1)
[l] [bar] [l] [kg] [mm] [mm] [mm] [mm]
ISO
228 [mm] [mm] [l/s]
0.5
standard
400 0.5 2.8 270
57
33.5 95.5
G 3/4 50 32
4
1
330
1.0
4.5 302
58
118
550 8.5 334 68 121 G 1
67
45
2.5
330 2.4 10 531 63 118 G 1 1/4 50 10
550 2.5 13.5 539 68 121 G 1 45 4
4
330
3.7
11.5
419 63 173 G 1 1/4 50 10
400 15.5
5 550 4.9 23 867 68 121 G 1 45 4
6 330 5.7 15 531
63 173
G 1 1/4
50 10
10
2)
330 9.3 25 728 G 1 1/4
10
standard
330
9.3 31.5 568 103
58
229
G 2 103 70
15
N 25
H 9 34.5 603 138 G 2 1/2 125 90 30
standard
400 9.3 37.5 572 103 233
G 2 100 70 15
500 8.8 41 585 77 68 241
13
standard
330
12
43 660 103
58
229
G 2 100 70
15
N 25
H 46 695 138 G 2 1/2 125 90 30
standard 400 49 666 103 233 G 2 100 70 15
20
standard
330
18.4 50.5 896 103
58
229
G 2 100 70
15
N 25
H 17.5 53.5 931 138 G 2 1/2 125 90 30
standard
400 18.4 63.5 896 103 233
G 2
100 70
15
500 17 75.5 901 77 68 241 110 75
24
standard
330
23.6 69.0 1062 103
58 229
G 2 100 70
15
N 25
H 24 72 1097 138 G 2 1/2 125 90 30
32
standard
330
33.9 87 1411 103
58
229
G 2 100 70
15
N 25
H 32.5 90 1446 138 G 2 1/2 125 90 30
standard
400 33.9 104.5 1411 103 233
G 2
100 70
15
500 33.5 127 1446 77 68 241 110 75
50
330
47.5
117.5 1931 103
68
229
G 2 100 70
15
N 25
H 120.5 1966 138 G 2 1/2 125 90 30
standard
400 142 1931 103 233
G 2 100
70
15
500 48.3 169 1951 77 241 75
60
standard 330
60 182 1156
138 68
356
G 2 1/2 125 90 30
80 85 221 1406
100 105 255 1656
130 133 305 1976
160 170 396 2006
406
200 201 485 2306
1)
Q = max. ow rate of pressure uid
2)
slimline version, for conned spaces
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3.2. SPARE PARTS
SB330/400/440/500/550
SB330H / SB330N
Detail "X"
SB330/400 – 0.5 ... 6 l
SB330/400/500 – 10 ... 200 l and
SB330H – 10 ... 200 l
SB550 – 1 ... 5 l
3.3. REPAIR KITS
NBR, carbon steel
Nom. volume: 0.5 ... 200 litres
Standard gas valve
Nom. volume [l] Part no.
0.5 02128169
1 02106261
2.5 02106200
4 02106204
5 02106208
6 02112100
10
*
)
03117512
10 02106212
13 02106216
20 02106220
24 02106224
32 02106228
50 02106252
60 03117513
80 03117514
100 03117515
130 03117516
160 03117517
200 03117558
*
)
slimline version for conned spaces
others on request
Description Item
Bladder kit
consisting of:
Bladder 2
Gas valve insert* 3
Lock nut 4
Seal cap 5
Valve protection cap 6
O-ring 7
Seal kit
consisting of:
O-ring 7
Washer 15
O-ring 16
Vent screw 19
Support ring 23
O-ring 27
Repair kit
1)
consisting of:
Bladder kit (see above)
Seal kit (see above)
Anti-extrusion ring 14
Oil valve assembly
consisting of:
Valve assembly (items 9-13) 9
Anti-extrusion ring 14
Washer 15
O-ring 16
Spacer 17
Lock nut 18
Vent screw 19
Support ring 23
* available separately
1)
When ordering please state smallest bladder
connection port size.
Item 1 not available as a spare part.
Item 19 for NBR/Carbon steel:
seal ring (item 20) included
Item 25 must be ordered as an accessory
(see Point 4).
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4. ACCESSORIES FOR BLADDER
ACCUMULATORS
4.1. ADAPTERS (GAS SIDE)
To monitor the accumulator pre-charge pressure, HYDAC offers a
selection of gas side adapters.
These must be ordered separately
4.1.1 Pressure gauge model:
Gas side connection on the bladder accumulator for permanent
monitoring of the pre-charge pressure
pressure gauge
Ø63
Gauge
indication range
Gauge
Part no.
Adapter body*
Part no.
Adapter
assembly
Part no.
– –
00239275
00366621
0 - 10 bar 00614420 02108416
0 - 60 bar 00606886 03093386
0 - 100 bar 00606887 02104778
0 - 160 bar 00606888 03032348
0 - 250 bar 00606889 02100217
0 - 400 bar 00606890 02102117
* p
max
= 400 bar
Gauge
indication range
Gauge
Part no.
Adapter body*
Part no.
Adapter
assembly
Part no.
– –
00363713
02103381
0 - 25 bar 00631380 02105216
0 - 60 bar 00606771 02110059
0 - 100 bar 00606772 03139314
0 - 160 bar 00606773 03202970
0 - 250 bar 00606774 03194154
0 - 400 bar 00606775 02103226
* p
max
= 400 bar
4.1.2 Pressure gauge model with shut-off valve
Gas side connection on the bladder accumulator for permanent
monitoring of the pre-charge pressure with shut-off option.
gauge Ø100
gauge shut-off
valve
approx.
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4.1.3 Remote monitoring of the pre-charge pressure
To monitor the pre-charge pressure in hydraulic accumulators
remotely, gas side adapters with pressure gauge and mounting
holes are available.
In order to connect these adapters directly with the hydraulic
accumulator using appropriate lines, accumulator adapters are
also available for connection at the top (see diagram 1) or for
side-connection (see diagram 2).
Gauge
indication
range
Gauge
Part no.
Adapter body*
Part no.
Adapter
assembly
Part no.
– –
02116746
03037666
0 - 10 bar 00614420 03095818
0 - 60 bar 00606886 03095819
0 - 100 bar 00606887 03095820
0 - 160 bar 00606888 03095821
0 - 250 bar 00606889 03095822
0 - 400 bar 00606890 03095823
* p
max
= 400 bar
D1
Threaded
connection
D2
[mm]
T Adapter
body*
Part no.
Adapter
assembly
Part no.
Diag.
ISO228- G 1/4 25
14
00238709 02109481 1
00241740 02102042 2
ISO228- G 3/8 28
00355021 02109483 1
03280414 00366607 2
ISO228- G 1/2 34 16
02110594 02110636 1
00237884 00366608 2
* p
max
= 400 bar
D1
Accum.
conn.
*
D2
D3
L1
L2
L3
SW
O-
ring
Part no.
(ISO228-
BSP) [mm] [mm] [mm] [mm] [mm] [mm] [mm]
NBR/
Carbon
steel
G 3/4
G 3/8 28 55 28 12 32
17x3
02104346
G 1/2 28 60 28 14 36 02104348
G 1 1/4
G 3/8 28 50 37 12 46
30x3
02116345
G 1/2 34 50 37 14 46 02105232
G 3/4 44 50 37 16 46 02104384
G 1 50 67 37 18 65 02110124
G 2
G 1/2 34 60 44 14 65
48x3
02104853
G 3/4 44 60 44 16 65 02104849
G 1 1/4 60 60 44 20 65 02107113
G 1 1/2 68 80 44 22 70 02105905
* others on request
pressure gauge
Ø63
O-ring
2 holes
approx.
Diagram 1 Diagram 2
4.2. ADAPTERS FOR STANDARD BLADDER
ACCUMULATORS (FLUID SIDE)
to connect the bladder accumulator to pipe ttings. These are
available separately.
5. NOTE
The information in this brochure relates to the operating
conditions and applications described. For applications and
operating conditions not described, please contact the relevant
technical department. Subject to technical modications.
Technology GmbH
Industriegebiet
D-66280 Sulzbach/Saar
Tel.: 0 68 97 / 509 - 01
Fax: 0 68 97 / 509 - 464
Internet: www.hydac.com
E-Mail: speichertechnik@hydac.com
O-ring 11x2
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