Title:表紙.ec6 Page:1 Date: 2014/12/15 Mon 09:38:19
HYDROPNEUMATIC
ACCUMULATORS
2014
Courtesy of JAXA
Title:中村工機-P02∼08.ec6 Page:2 Date: 2014/12/15 Mon 09:14:44
Functions & Effects
■ Energy Storage (power compensation)
This is the most common usage of the accumulator to store energy from an external pressure source during
idle time and to discharge the energy as necessary. Concretely speaking, it is used to make pump/motor size
small and also used as an auxiliary power source in emergency, as a hydraulic starter for an internal
combustion engine and as aid for pump delivery at the time of high-speed activation of an actuator, etc.
■ Shock absorption of Water hummer and Surge pressure
Suddenly shutting off a high-pressure and high-flow pipeline generates large impact pressure. In other cases
mechanical shock to an actuator from external may cause fluid vibration and thus damage to equipment. The
accumulator mitigates these shocks.
■ Pump pulsation damping
Pulse pressure in a single, dual or triple piston pump for high pressure operation makes control of a pressure
device difficult. However, by using the accumulator, not only the trouble due to pulse pressure but also the
knocking phenomenon due to smallness feeding from a cylinder of a machine tool etc. can be solved.
■ Leak compensation
The accumulator compensates for the pressure drop caused by a leak that may occur by keeping an actuator
at a fixed position for a long time or by clamping something.
The hydro-pneumatic accumulator is a storage vessel for pressurized fluid that
utilizes compressed gas. Energy from compressed gas makes pressured fluid
discharge from the vessel. The bladder type accumulator has a soft rubber bag,
that separates compressed gas and non-compressed fluid, and gas is charged
into the bag. One of big characteristics of the bladder type accumulator is to have
many other functions than energy storage.
■ Compensation in temperature change
The accumulator reduces the pressure rise in closed pipe-lines under the burning sun and compensates for
the pressure drop caused by fluid contraction in cold area.
■ Hydraulic balancing
By using the gas pressure in the accumulator as a weight, cylinder friction leads vertical movement of a
machine tool head or a television camera.
■ Hydro-pneumatic shock absorption
The accumulator serves as a spring for absorbing shock between the body and wheels of a vehicle. In
addition, it can be utilized as a pneumatic spring for various squeeze rolls. The accumulator provides lessfatigue and high absorption efficiency of impact energy as compared to a spring.
■ Transfer barrier
This is the method to transfer the hydraulic pressure from one side to the other without mixing each fluid. In
this method, the accumulator serves as a gas compressor or transfers corrosive fluid. In order to reduce the
accumulator pressure change caused by charging or discharging fluids, the accumulator can also be operated
with low differential pressure by increasing its gas chamber volume.
■ Fluid supply
The accumulator is used for supplying lubrication oil in emergency or used as a portable oil lubricator.
２
●
Title:中村工機-P02∼08.ec6 Page:3 Date: 2014/12/15 Mon 09:14:46
SYMBOL
COMMON
Accumulator Volume
Calculation
△ V : Available Discharge Volume of Acc. ()
P１: Precharge Pressure (MPa･A)
P２: Min Working Pressure (MPa･A)
P３: Max Working Pressure (MPa･A)
n : Polytropic Exponent at Discharge time (Per Graph Below)
m : Polytropic Exponent at Charge time (m=n-0.2)
V１: Accumulator Gas Volume ()
Energy Storage
１
FORMULA
CALCULATION
Surge Absorption
P
（
P ）
V=
P
− 1
P
（
）
P
P
− 1
P × V
（P ） △ V=
P P
（P ）
３
△ V × P２×
３
１
２
２
１
１
Pulsation Dampening
１
m
１
n
１
n
３
PＡ : Nomal Working Pressure (MPa･A)
PＸ : Average Working Pressure (MPa･A)
PＢ
Max
Allowable Pressure (MPa･A)
Pｍ
M : Mass of Fluid in Line (㎏)
υ : Flow Velocity (m/sec)
q : Pump Delivery per a Revolution (/rev)
F１ : Pump Coefficient (See the graph below.)
M ×υ２× (n − 1)
V１=
P Ｂ n−n 1 2000×P１×
− 1
P Ａ
V１=
（ ）
（ ）
1− P
（P ）
Pχ
q × F１ P１
１
χ n
ｍ
３
Pump Type
Simplex
Duplex
Triplex
２
2
F１ : Pump Coefficient
１
m
Note : P１=0.6P Ｘ
２
Quadruplex
Note :
Note: Assuming the discharge/charge time as "1 or less", "n" is
Quintuple
In isothermal change, n=m=1. found from the average pressure value in the graph below.
F１
single acting
double acting
single acting
double acting
single acting
double acting
single acting
double acting
single acting
double acting
0.6 0.25
0.25
0.15
0.13
0.06
0.10
0.06
0.06
0.02
LIMIT
(1)The magnitude relationship of pressure should be 0.25 × (P3 or PB or Pm ) ≦ P ≦ 0.9 × (P2 or PA or PX ).
(2) In case of n ＜ m in energy storage, make the value of“n”as“m”(but it should be over 1)
Polytropic Change & Exponent Graph
(Check the exponent value from the discharge/charge time and the average pressure value.)
３０
2.4(2.2)
2.3(2.1)
2.2(2.0)
2.1(1.9)
２５
2.0(1.8)
1.9(1.7)
1.8(1.6)
１５
1.7(1.5)
１０
1.6(1.4)
５
1.5(1.3)
１or
less
1.4(1.2)
1.3(1.1)
Polytropic exponent n, m →
P２+P３
Average pressure (MPa･A) →
２
２０
1.2
1.1(1.0)
１or
less
2
3
4
5
6 7 8 9
10
20
30
40
50
60708090
100
200
Discharge time, Charge time (sec) →
300 400
500
600
800
700 900
1000
1.0
2000 3000 4000
Discharge time (P3 → P2)
Charge time (P2 → P3)
↑ ↑
n (m)
Example:
1. On the assumption that the discharge time is 5sec and the average pressure is 5MPa, the polytropic exponent is 1.41.
2. On the assumption that the charge time is 5sec and the average pressure is 5MPa, the polytropic exponent is 1.21.
Note: Refer to the above broken lines.
３
●
Title:中村工機-P02∼08.ec6 Page:4 Date: 2014/12/17 Wed 17:53:10
Exercise 1, Energy Storage :
Operate a 500kN press machine, that ram diameter is φ200mm. The stroke is 115mm, the work time is 1.5sec and the
idle time for removing the work is 2min. On the premise of the above, we compare two cases, Case 1 is to use a pump and
a motor only and Case 2 is to add an accumulator to them. How will the size change? The answer is shown in Table 1.
＜ Case 1: Pump and Motor only ＞
＜＜ Case 1: Calculation ＞＞
500 × 103N
Ram dia. 200mm, Required pressure= =15.92
≒１６MPa (Ram area=202 × 0.785=314 )
314 × 102
Fluid required for 1 stroke=314 × 11.5㎝=3,611cc=3.7
3.7 Fluid volume required in a second= =2.47/sec
1.5 sec
Flow volume required in a minute=2.47 × 60=148.2/min ≒ 149/min
149 /min × 16 MPaG 39.0
Motor= ≒ ≒ 47.6 kW ≒ 55 kW
61.2 ×
η
ρ(Pump Efficiency) 0.82
＜＜ Case 1: Result ＞＞
The required fluid volume of the pump = 149/min, The required pressure = 16MPa or more, Motor capacity = 55kW
︸
︸
︷
︷
＜ Case 2: Pump, Motor and Accumulator ＞
If an accumulator is added to the system, there are two approaches (Formula: Press power=Pressure × Ram
dimension). One method is to adopt the press cylinder with a larger bore in consideration of the pressure drop (P3 →
P2) during fluid discharge(in case of the bladder type accumulator). Another method is to design the accumulator's max
working pressure such that its minimum pressure of the accumulator becomes to 16MPaG at the end of discharge(in
this case, the max pressure is designed as 21.5MPaG). Let us work on the latter example. In this case, the accumulator
with the max pressure of 21.5MPaG and the pump with 21.5MPaG power are used together. The calculation for pump
and motor size is as follows,
＜＜ Case 2: Calculation ＞＞
△
V × P2(P3/P2)1/m
Table 1:Comparison table of Case 1 and Case 2
V1= P1 （P3/P2）1/n − 1
Case 1
Case 2
Notes : ◎ On the pressure, convert (MPaG+0.1) into MPaA
Required pressure 16MPaG
21.5MPaG
◎ Refer to following item f as to P1
Pump
149/min
1.9/min
3.7
× 16.1(21.６/16.1)1/1.2８ =32.5 ≒ 33 V1= 1/1.85
Motor
55kW
1.1kW
13.4 （21.6/16.1） − 1
Accumulator
None
33
3.7 Flow rate to accumulator= =1.9/min
2min
1.9 /min × 21.5 MPaG
≒ 1.1kW
Motor= =0.82kW
61.2 × 0.82
＜＜ Case2: Result ＞＞
The required pressure: 1.35 times bigger than Case1, The pump volume: 1/79 size of Case 1, The motor size: 1/50 size of
Case 1.
＜ The sample procedure to select the accumulator model for exercise 1 ＞
a. As the required pressure is 21.5MPaG, the model shall be G230 or T230 (Ref. pages 8 and 9).
b. As the calculated gas volume is 33, the nominal gas volume is 30 (Ref. pages 8 and 9).
c. As the required fluid volume is 149/min, it is within the range of the max allowable discharge flow shown in the
G/T series (Ref. pages 8 and 9).
d. If the fluid is mineral oil/water-glycol and the working temperature is under 80℃, the bladder material is NBR #20
(Ref. page 6).
e. If a flange is used for piping, the oilport flange's type is OPE-D32 with a mating flange (Ref. page 16).
As a result of the above (a. ∼ e.), the accumulator model shall be“G/T230-30-20-OPF-D32 with a mating flange”.
f. Confirmation of the Precharge pressure (P1)
As the basic information, the higher the pre-charge pressure (P1) is, the bigger △ V increases. At the same time, P1
should be within the range of P1 ＜ 0.9 × P2. Taking into consideration the case that the fluid temperature may increase
during operation, P1 shall be designed as consistently less than 90% of P2. If P1 becomes higher than P2, the bladder
lifetime will be short.
Absolute temperature at precharging
P1= × 0.9 × P２ 273+26
= × 0.9 × 16.1=13.4 MPaA
~ Max absolute temperature
273+50
When the value of P1 is 13.3MPaG, ⊿V shall be 3.7 .
４
●
Title:中村工機-P02∼08.ec6 Page:5 Date: 2014/12/15 Mon 09:14:47
Exercise 2, Pulsation Damping :
The calculation formula to select the accumulator model for pulsation damping is as follows,
＜ Conditions Precedent ＞
Symbol
P1
Px
Pm
N
Q
F1
q
n
Meaning
Precharge pressure
Average working pressure
Max allowable pressure
Pump type
Revolution of pump
Pump delivery
Pump coefficient
Pump delivery per revolution
Polytropic exponent
Details 1
3MPaG
5MPaG
Px ＋3％ = 5.15MPaG
Simplex & Single acting
62rpm
32/min
0.6
Q/N
Average pressure = 5.1MPaA
Details 2
3.1MPaA
5.1MPaA
5.25MPaA
32/62
1.51
＜ Calculation Formula ＞
V１=
（ ） = 62 × 0.6 ×（3.1）=26.８
5.1
1− P
（P ） 1 −（5.25
）
Pχ
q・F１・ P１
32
１
χ n
5.1
1/1.5１
ｍ
＜ Result ＞
The gas volume of the accumulator to control pulsation within ±3% of the average working pressure is 26.8 . For
your information, the pump delivery per a revolution can also be calculated by checking the pump plunger size and its
stroke.
a. Refer to Exercise 1 for accumulator model selection.
b. Refer to page 7 for the effects of pulsation damping.
Exercise 3, Surge Pressure Absorption :
The calculation to get the required gas volume of the accumulator for surge pressure absorption is as follows,
(Purpose & Situation: Absorbing the surge pressure due to sudden closing of the valve in the pipe end.)
＜ Conditions Precedent ＞
Symbol
L
Meaning
Total length of oil piping
D
External diameter of piping
d
Q
PA
PB
P1
υ
n
ρ
Internal diameter of piping
Fluid volume
Normal pipe-line pressure
Max allowable pressure
Precharge Pressure
Flow velocity
Polytropic exponent
Fluid specific gravity
Details 1
8B × Sch40
(JIS : 216.3mm × Thickness 8.2mm)
216.3mm8.2mm8.2mm
4500/min
0.53MPaG
1.13MPaG
P1 ≦ 0.9 × PA = 0.9 × 0.63MPaA
4/ π× Q/d2 = 21.23 × 4500/199.92
Average pressure=(1.23+0.63)/2 ≦ 1
-
Details 2
700m
216.3mm
199.9mm
0.63MPaA
1.23MPaA
0.53MPaA
2.4m/sec
1.405
900kg/m3
＜ Calculation Formula ＞
π π
M= d２･L･ ρ = × (199.9 × 10−3)２× 700 × 900=19772㎏
4 4
(M: Mass of fluid in piping line (kg))
M ×υ２× (n − 1)
19772 × 2.4２× (1.405-1)
=
P Ｂ n１ 1.23 0.2８８３ = 205
n
2000
×
0.53
×
2000×P１×
−
1
− 1
P Ａ
0.63
＜ Result ＞
The required gas volume of the accumulator is 205.
V１=
（ ）
（ ）
＜ Note ＞
Please refer exercise 1 about the procedure of selecting the accumulator model.
５
●
Title:中村工機-P02∼08.ec6 Page:6 Date: 2014/12/15 Mon 09:14:48
Explanation of
Model Symbols
G □ 350 − 20 H − 20 − OPF − J − 32 − CG 60M − MT − S7
Mark for NAS cleanliness class in a
servo circuitry etc. Select the class
from 6, 7 or 8.
If standard (not required the class),
no mark.
MT…Safety device for gas port.
If not specified,
60M … Glycerol filled pressure
a standard gas
gauge for gas port.
valve will be
CG…Coreless type Gas Port provided.
(Ref. page 14).
A standard bushing (Rc
connection) will be
Oilport flange model name(Ref. page 16). provided, if not specified.
Nominal diameter of a mating flange
Rubber materials
10 Nitrile rubber (NBR)
Low Temperature
− 25 to+80℃
20 Nitrile rubber (NBR)
Mineral oil, water glycol
− 10 to+80℃
30 Epichlorohydrin (CHC)
Gasoline, etc., Aromatic material − 10 to+90℃
40 Butyl rubber (IIR)
Phosphate ester
28 Fluorocarbon rubber (FKM) Chemical material
− 10 to+90℃
− 5 to+120℃
Types
Standard
Ref. pages 7, 8, and 9
H
High flow type
High flow discharge (Ref pages 8&9)
P
Screen type
Poppetless (Ref. page 11)
B
Transfer barrier type
Transfer of dissimilar fluid (Ref. page 12)
Nominal gas volume of the accumulator ( )
Maximum working pressure (kgf/ )
Surface treatment and Material
Mark Contents
Parkerizing
W
Nickel plating
S
Stainless steel
F
PTFE coating
Fluid type Material
For mineral oil and water glycol
For Water,
etc.
Shell : Nickel plating Connection : Stainless steel
Shell&Connection: Stainless steel
Shell inside: PTFE coated Connection: Stainless steel
Accumulator Series
６
●
M
Miniorator Series
Small volume type
Ref. page 7
G
General Series
Standard type
Ref. page 8
T
Twin Open Series
Open top type
Ref. page 9
D
Damper Series
In-line type
Ref. page 10
Title:中村工機-P02∼08.ec6 Page:7 Date: 2014/12/15 Mon 09:14:49
M-Series
MINIORATOR
Model
M210
Spec.
Max. W.P
20.6MPa
Gas type
N２ gas
Precharge
pressure
limits
Instailation
Surface
treatment
Model
symbols
0.25 × P3 ＜ P1 ＜ 0.9 × P2
(P1=Precharge pressure, P2=Min working pressure, P3=Max working pressure)
Vertically (Oil side is downward)
Fluid = Oil : Parkerizing
Fluid = Water, etc. : Nickel plating
Note: Stainless steel type is shown in page 13.
20. (NBR)Mineral Oil
M 210−1−20
Rubber 40. (IIR)Phosphate Ester
Materials 28. (FKM)Chemical Material
Nominal gas volume of accumulator ()
Max working pressure
Series
Dimensions Max W.P. Gas volume
Mass
A
UD
D
B
（MPa）
（㎏）
(mm)
(mm)
(mm)
(mm)
Model
M210-0.1
M210-0.3
M210-0.5
20.6
M210-1
（）
E
(mm)
Max allowable
discharge flow
(/min)
F
0.115
2.0
232
74
60.5
85
−
Rc1/4
62
0.29 5.0
286
94
76.3
85
35
Rc3/4
92
0.5 6.3
376
94
76.3
85
35
Rc3/4
92
1.0 12.5
398
124
107.9
85
10
Rc3/4
260
◎ Maximum allowable discharge flow is designed to avoid the stopper's chattering phenomenon due to pressurized fluid.
◎ Maximum allowable discharge flow is designed in the case where the fluid material is mineral oil VG46.
■ Examples in Pulsation damping effects
(A) Without
ACC.
(B) With ACC.
Ex.1 0.5bladder type ACC.
(A) Without
ACC.
(B) With ACC.
Ex.2 0.5bladder type ACC.
７
●
Title:中村工機-P02∼08.ec6 Page:8 Date: 2014/12/15 Mon 09:14:50
G-Series
GENERAL SERIES
Spec.
Model
Max. W.P.
G175
G230
G300
G350
17.2MPa
22.6MPa
29.5MPa
34.4MPa
Gas type
N２ gas
Precharge 0.25 × P3 ＜ P1 ＜ 0.9 × P2
pressure
(P1=Precharge pressure, P2=Min working pressure, P3=Max working pressure)
limits
Installation Vertically (Oil side is downward)
Fluid = Oil : Parkerizing
Surface
Fluid = Water, etc. : Nickel plating
treatment
Note: Stainless steel type is shown in page 13.
10. (NBR)Low Temperature
G 230−10 H−20
20. (NBR)Mineral Oil
Rubber
30. (CHC)Aromatic Material
Materials 40. (IIR)Phosphate Ester
28. (FKM)Chemical Material
Model
Hi-Flow TYPE
symbols
Nominal gas volume of the accumulator ()
Max working pressure
Series
Dimensions
Model
G175−1
−2.5
−4
−5
−10
−20
−30
−50
−60
G175−10H
−20H
−30H
−50H
−60H
G230−10
−20
−30
−50
−60
−10H
−20H
−30H
−50H
−60H
G300−1
−2.5
−4
−5
G350−1
−10
−20
−30
−50
−60
−10H
−20H
−30H
−50H
−60H
Max W.P. Gas volume Mass
（MPa） （） （㎏）
1.2
9
2.4
15
3.7
18
4.7
20
12.0
44
20.8
61
37.2
96
17.2
53.1
128
64.7
152
11.3
59
20.1
76
36.5
111
52.4
143
64.0
167
10.6
55
19.0
79
34.0
127
48.5
172
59.4
206
22.6
9.9
70
18.5
94
33.6
142
48.1
187
58.7
221
1.2
10
29.5
2.4
20
3.6
19
29.4
4.6
22
1.2
10
10.1
65
19.0
102
34.2
163
49.3
219
34.4
60.0
262
9.4
80
18.3
117
33.5
178
48.7
234
59.3
277
A
(mm)
391
577
474
536
660
933
1444
1952
2318
649
922
1433
1941
2307
662
935
1446
1954
2320
653
926
1437
1945
2311
391
577
458
514
391
647
945
1456
1964
2322
633
931
1442
1950
2308
B
(mm)
C
(mm)
107
64
106
89
D
E
F
(mm) (mm)
118 Standard unit
120 10 comes with a
168.3
bushing Rc3/4
connection.
As to a flange
15 connection, refer
to page 16.
232 Connection is flange
Max allowable
discharge flow
(/min)
OPF-S
108
1400
3600
(Ref. to page 16)
101
89
232 Standard unit comes with
a bushing Rc3/4
15 connection.
As to a flange connection,
refer to page 16.
1400
Connection is flange
OPF-S or OPF-J
103
3600
(Ref. to page 16)
107
64
107
64
120 127 177.8
120 101
89
241.8
103
Standard unit
10 comes with a
bushing Rc3/4
connection.
As to a flange
15 connection, refer
to page 16.
342
1400
Connection is flange
OPF-J
(Ref. to page 16)
◎Refer to page 16 for flange connection.
◎Maximum allowable discharge flow is designed in the case where the fluid material is mineral oil VG46.
８
●
342
3600
Title:中村工機-P09∼17.ec6 Page:9 Date: 2014/12/15 Mon 09:21:29
T-Series
TWIN OPEN SERIES
■ Features :
A large opening is provided on the top for ease of maintenance.
Because the bladder is pear-shaped to expand and contract easily, the excessive
deformation tends not to occur and the life span is long.
The bladder body doesn't have a seal structure, so special skill for maintenance is
not required.
In the way of customer's convenience the bladder can be replaced from both ports
in top and bottom.
The shell body has assembly structure without screw clamps, so customer is free
from stripped screws trouble in disassembly.
■Model symbols :
T 175 − 10 H − 20
10. (NBR) Low Temperature
20. (NBR) Mineral Oil
Rubber 30. (CHC) Aromatic Material
Materials 40. (IIR) Phosphate Ester
Hi-Flow TYPE 28. (FKM) Chemical Material
Nominal gas volume of the accumulator ( )
Max working pressure
Series
Dimensions
Model
T175−10
−20
−30
−50
−60
−10H
−20H
−30H
−50H
−60H
T230−10
−20
−30
−50
−60
−10H
−20H
−30H
−50H
−60H
T350−10
−20
−30
−50
−60
−10H
−20H
−30H
−50H
−60H
T120−40
−58
−80
−120
−180
T175−40
−58
−80
−120
−170
TL175−170
−230
T230−40
−58
−75
−120
−170
TL230−160
−220
T350−40
−58
−70
−100
−160
TL350−160
−220
Max W.P.
（MPa）
17.2
22.6
34.4
11.8
17.2
22.6
34.4
Gas volume
（）
11.6
20.4
36.8
52.7
64.3
10.9
19.7
36.1
52.1
62.6
10.3
18.8
33.8
48.3
59.0
9.6
18.2
33.2
47.7
58.3
9.7
18.6
33.8
48.9
59.6
9.6
17.9
33.1
48.3
58.9
43.0
61.0
79.0
127.0
183.0
41.0
58.0
75.0
120.0
170.0
167.0
222.0
37.0
54.0
70.0
112.0
164.0
157.0
213.0
35.0
51.0
66.0
103.0
155.0
152.0
205.0
Mass
（㎏）
45
62
97
129
153
60
77
112
144
168
56
80
128
173
207
71
95
143
188
222
67
104
165
221
264
84
119
180
236
279
110
136
162
234
316
155
192
227
323
439
423
549
177
222
270
391
535
531
689
214
267
321
459
636
609
792
A
(mm)
673
946
1457
1965
2331
662
935
1446
1954
2320
673
946
1457
1965
2331
664
937
1448
1956
2322
657
955
1466
1974
2332
663
941
1452
1960
2318
918
1144
1364
1968
2666
918
1144
1364
1956
2670
2046
2652
918
1144
1364
1956
2670
2056
2662
918
1144
1364
1950
2700
2056
2662
B
(mm)
C
(mm)
D
(mm)
106
E
(mm)
F
15
Standard unit comes with
a bushing Rc3/4
connection.
As to a flange connection,
refer to page 16.
110
Max allowable
discharge flow(/min)
1400
Connection is flange
108
3600
OPF-S
(Ref. to page 16)
232 101
15
Standard unit comes with
a bushing Rc3/4
connection.
As to a flange connection,
refer to page 16.
1400
Connection is flange
103
OPF-S or OPF-J
3600
(Ref. to page 16)
107
101
15
241.8
Standard unit comes with
a bushing Rc3/4
connection.
As to a flange connection,
refer to page 16.
1400
103
110
108
355.6
Connection is flange
OPF-S
(Ref. to page 16)
105
103
355.6
102
100
406.4
105
103
355.6
102
100
406.4
3600
Connection is flange
OPF-S or OPF-J
(Ref. to page 16)
105
103
355.6
102
100
406.4
◎ Refer to page 16 for flange connection.
◎ Maximum allowable discharge flow is designed in the case where the fluid material is mineral oil VG46.
９
●
Title:中村工機-P09∼17.ec6 Page:10 Date: 2014/12/15 Mon 09:21:30
Damper series
(In-line type) Accumulator
D-Series
Flow
Across Flats 55
■ Features :
●Because the fluid directly flows along the surface of the bladder, the bladder can absorb high frequency
pulsations.
●A valid and feasible model for prevention of water hammer, surge pressure and noise, etc.
●Because the accumulator is directly installed into pipe-line, customer can save the space and this alleviate
concern about contamination due to fluid residence.
●The bladder body doesn't have a seal structure, so special skill for maintenance is not required.
■Model symbols :
D 215 − 02 − 20
Rubber 20. (NBR) Mineral Oil
40. (IIR) Phosphate Ester
Materials 28. (FKM) Chemical Material
Nominal gas volume of the accumulator ( )
Max working pressure
Series
Model
Dimensions
D215-02
D215-1.5
Max W.P.
（MPa）
21.0
Gas volume
（）
Mass
（㎏）
A
(mm)
B
(mm)
0.19
8.0
328
131
Rc 1
167
40A Flange
Connection
1.2
33.0
400
C
D
(mm)
Max allowable
flow rate
(/min)
80 140
154
420
◎If flange connection is applied, the position of the bolt-hole of each flange is different in rotation direction.
The mating flanges and the seal parts will be provided.
■Example in Pulsation damping effects
(A) Without
ACC.
１
０
●
(B) With ACC.
Title:中村工機-P09∼17.ec6 Page:11 Date: 2014/12/15 Mon 09:21:31
P-Type
Screen Type Accumulator
Screen type can be applied to G series and T series. Screen type has a plate with many small holes to allow fluid to
pass through, in lieu of a poppet valve placed at the oil port. Max allowable precharge pressure is 0.75MPaG and the
bladder of this type is free from damage due to a poppet even if the fluid pressure will be under the precharge pressure
or be same to atmosphere pressure. This type is widely used for surge pressure damping in a water pipeline at lowpressure use or in pipelines in petrochemical industries, etc.
Screen type in General series
■Model symbols :
G 30 − 10 P − 20 − For a bushing connection, specify Rc diameter.
For a flange connection, specify the standard and
nominal diameter of it.
10. (NBR) Low Temperature
Rubber 20. (NBR) Mineral Oil
30. (CHC) Aromatic Material
Materials 40. (IIR) Phosphate Ester
28. (FKM) Chemical Material
P-Screen type
Nominal gas volume of the accumlator ( )
Max working pressure (3.0 MPa)
Series
If the Twin Open Series is required, indicate “T”.
Dimensions
Model
G30−1P
−2.5P
−4P
−5P
G30−10P
−20P
−30P
−50P
−60P
T30−10P
−20P
−30P
−50P
−60P
T30−80P
−120P
−180P
Max W.P. Gas volume Mass
（MPa）
（） （㎏）
1.2
9
2.4
11
3.7
18
4.7
20
11.3
59
20.1
76
36.5
111
52.4
143
3.0
64.0
167
10.9
60
19.7
77
36.1
112
52.1
144
62.6
168
79.0
162
127.0
234
183.0
316
A
(mm)
391
577
474
536
649
922
1433
1941
2307
662
935
1446
1954
2320
1364
1968
2666
B
(mm)
C
(mm)
107
64
D
(mm)
118 120.0
168.3
E
(mm)
F
Max
flow rate
(/min)
Bushing
height 10
(Ref. to page 8)
Standard unit comes with a
bushing Rc3/4 connection.
As to a flange connection,
refer to page 16.
75
89
232 Connection is
OPF-S.
108
700
(Ref. page 16)
110
355.6
◎ Max flow rate is calculated under the situation where the pressure difference between the accumulator and
the pipe line is 1.18MPa.
◎ Max flow rate is designed in the case where the fluid material is mineral oil VG46 at 28℃.
１
１
●
Title:中村工機-P09∼17.ec6 Page:12 Date: 2014/12/15 Mon 09:21:31
Transfer Barrier
Accumulator
Type
B-Type
Transfer barrier accumulators are used to transfer pressure between different types of fluid, for example, the pressure
between oil and water, clean oil and contaminated oil, liquid and gas, etc. A perforated tube is installed into the bladder
to prevent the bladder from damage due to the fluid's direct contact with the interior of the bladder. Concretely
speaking, this type accumulator is used to convert oil pressure to water pressure and/or supply oil to a compressor
bearing, etc.
Transfer Barrier Type in T series
■Model symbols :
T 175 − 20 B − 20 − For a bushing connection, Rc3/4 is provided
as standard for both gas and oil port sides.
For a flange connection, specify the standard
and the nominal diameter of the flange.
10. (NBR) Low Temperature
Rubber 20. (NBR) Mineral Oil
30. (CHC) Aromatic Material
Materials 40. (IIR) Phosphate Ester
28. (FKM) Chemical Material
“B”means Transfer Barrir Type
Nominal gas volume of the accumulator ( )
Max working pressure
Series
If the Gneral Series is required, indicate“G”.
Dimensions
Model
G175−20B
−30B
−50B
−60B
T 175−20B
−30B
−50B
−60B
T 175−80B
−120B
−170B
Max W.P. Gas volume Mass
（MPa） （） （㎏）
20.8
61
37.2
96
53.1
128
64.7
152
20.4
62
17.2
36.8
97
52.7
129
64.3
153
75.0
227
120.0
323
170.0
439
A
(mm)
954
1465
1973
2339
951
1462
1970
2336
1374
1966
2680
B
(mm)
C
(mm)
D
(mm)
E
(mm)
106
232
55
F
110
Reference
dimension,
ASME 150LB
115
1B RF
103
355.6
90
◎In case where the mineral oil VG46 flows at 200/min, the pressure loss of the perforate tube shall be
about 0.08MPa.
◎The bladder's compression ratio shall be within (0.2P3≦P1≦0.9P2) or within (V3≧0.2V1, V2≦0.9V1).
12
●
Title:中村工機-P09∼17.ec6 Page:13 Date: 2014/12/15 Mon 09:21:32
Stainless Steel
Accumulator
M.G.T. Series
Recently, accumulator came to be used for not only oil system but also water/special liquid system being operated by
high purity washing water, high cleanliness chemical fluid, etc.
For such applications, a stainless steel accumulator is most appropriate.
■ Features :
The material is stainless steel that has high anti-corrosiveness such as SUS304, SUS316L, etc.
Customer can maintain a high cleanliness level in the lubricating system, the hydraulic system, etc. by using this
accumulator.
The shell is designed under JISB8358 and is non-weld integral structure made from seamless tube.
Titanium (TB480H) bladder type accumulators are also available.
The special model with the max working pressure up to 34.4MPaG can be supplied.
Stainless Steel Type in G Series
■Model symbols :
G S 70 − 50 − 20 − For flange connection, specify the standard and
the nominal diameter of flange.
10. (NBR) Low Temperature
Rubber 20. (NBR) Mineral Oil
30. (CHC) Aromatic Material
Materials 40. (IIR) Phosphate Ester
28. (FKM) Chemical Material
Nominal gas volume of the accumulator ( )
Max working pressure
“S”means Stainless Steel Type
Series
M − Miniorator Series
G − General Series
T − Twin Open Series
Dimensions
Model
MS210−0.1
−0.3
−0.5
−1
GS140−1
−2.5
−4
−5
GS70−10
−20
−30
−50
−60
TS70−10
−20
−30
−50
−60
TSL60−100
−170
−240
Max W.P. Gas volume
（MPa） （）
0.115
0.29
20.6 0.5
1.0
1.0
2.4
13.8 3.4
4.4
12.0
21.3
7.0
38.7
56.1
67.6
11.5
20.8
7.0
38.2
55.6
67.1
101.0
6.0
167.0
237.0
Mass
（㎏）
2
5
6.3
10.5
9
12.5
21
24
35
48
76
101
120
37
50
77
103
123
162
240
320
A
(mm)
232
286
376
398
391
577
500
558
656
929
1440
1948
2314
665
938
1449
1957
2323
1323
1938
2578
B
(mm)
85
107
89
C
(mm)
74
D
(mm)
60.5
E
(mm)
−
94
76.3
35
115
100
※ UD
Ref.
page 7
10
F
Rc1/4
64
114.3
104
177
15 comes with a
bushing Rc3/4
106
232
connection.
15 As to a flange
Standard unit
connection, refer
to page 16.
104
101
232
107
105
406.4
15
A flange connection is
OPF-S (Ref. page 16).
◎The dimensions of E and F written in the above table is our standard size. If other standard such as
ASME, API, JPI or DIN or other special material is required, please let us know the specification.
◎Please let us know your desired allowable flow rate.
１
3
●
Title:中村工機-P09∼17.ec6 Page:14 Date: 2014/12/15 Mon 09:21:33
Accessories on gas side
1. Coreless type gas port
Pressure gauge
Circuit diagram
Stop valve
Bleed plug
REF. 160
Bleed
plug
Glycerol filled
pressure gauge
Stop valve
Coreless valve
(N2 gas suppiy port)
Coreless
valve
MT or SP
TV8(8V1)
(N2 gas
supply port)
Safety device
Connecting to accumulator, 7/8"-14UNF
set screw
Accumulator
conenecting port
REF. 69.5
■Model symbols :
Max. scale of
−
pressure gauge
G 230 − 50 − 20 − CG
Safety unit
Coreless type gas port (Approved by the Japanese
High Pressure Gas Safety Act of METI)
Type
CG
Max working pressure Pressure test value
34.4MPa
Glycerol filled pressure gauge
Rubber materials
Nominal gas volume of the accumulator ( )
Max working pressure
Series
Note:
Only a charging hose assembly is required when the coreless type gas port
is being installed. In other words, the charging valve assembly is not
required when the coreless type gasport is being installed.
Standard max scale value Working presure range
25MPa
0 ∼ 18MPa
40MPa
0 ∼ 25MPa
60MPa
0 ∼ 34.4MPa
Not required for 10 or more liters accumulator because
this is being installed in the bladder assembly.
Safety-unit Type
MT
SP
2. Charging Assembly :
Charging Valve
(VR type)
Hose connection
Melting Temperature
105 ± 5℃
Stop plug
Caution in the case where the charging pressure is
extremely low pressure.
When the charging pressure toVR type gas valve is less
than 1MPa, there is possibility not to be able to charge
gas into an accumulator due to the cracking pressure of
the check valve (core) of the charging valve.
Therefore, if the charging pressure is less than 1MPa,
please let us know before you order. The charging valve
(VRZ type) for extremely low pressure is recommended.
If you have any questions, please feel free to contact us.
TV8(8V1)
Connecting to accumulator
Charging Hose Assembly
Charging
Max working
Standard
Hose Type
TS150
TS400
pressure
14.7MPa
39.2MPa
length
2m
2m
Full length : Approx.2000
14
●
52MPa
G1/4
for JIS Nitrogen bottle-Type A
W22-14
W23-14
for JIS Nitrogen bottle-Type B
Title:中村工機-P09∼17.ec6 Page:15 Date: 2014/12/15 Mon 09:21:34
■Model symbols :
Circuit diagram
Charging Hose Assembly
Charging Valve
↓
↓
VR ※
TS ※×※
−
Bleed
plug
Length
Pressure
gauge
Leave blank if it is standard (2m).
Charging
Hose assembly
Enter the no. of length you desire.
Indicate the rated pressure,(kgf/ )-150, 400
Hose Type
Connecting to accumulator, 8V1 (TV8)
Max scale of pressure gauge-(indicated in MPa.)
(Pressure gauge size is AT 1/4 ×φ60)
Charging Valve type: VR-type for an accumulator with a coreless type gas valve
Note: If the charging gas pressure is less than 1MPaG, please let us know before you order.
3. Melting plug :
Melting plug is a safety device to protect the accumulator from abnormally high temperature environment.
■ Features :
●Melting plug doesn't have moving parts, so it is dependable as a safety device.
●Because Melting plug is installed separate from the gas supply valve seat, there is not damage due to
charging gases.
●Even if the fuse is melted by fire disaster, the valve-guard prevents the melted piece from blasting off.
●Because Melting plug is being incorporated into the valve stem of bladder, this is renewed by replacing the
bladder and no extra space is required.
●Melting plug is safe against external shocks, etc.
Standard melting temperature is 105 ± 5℃. The temperature is designed for the plug to start melting at the time when
the accumulated pressure increases higher than the accumulator's max pressure.
After that, the accumulated gas is discharged from the plug hole and controlled not to greatly exceed the max
pressure.
Please take care that there is a possibility the plug starts melting during operation in high temperature environment
over 80 ℃, and it leads gas leak. In this case, we recommend to use Melting plug for high temperature, that starts
melting at 180 ± 10℃.
To select appropriate safety device, please let us know before you order.
Gas valve assembly
Melting plug
Gasket
Fusible metal
N2 gas
１
５
●
Title:中村工機-P09∼17.ec6 Page:16 Date: 2014/12/15 Mon 09:21:36
OPF Series
OIL PORT FLANGE
If a flange connection is applied, we recommend to choose it from models shown in the followings.
■Model symbols :
G 230 − 10 − 20 − OPF − B20 (Require a mating flange.)
Please indicate the oil port flange model name if applied. In addition, please let us know whether a
mating flange is required or not. Blank means to select our standard bushing(Rc3/4).
Rubber material
Nominal gas volume of the accumulator ( )
Maximum working pressure.
Accumulator series.
※ All oil port flange comes with seal parts.
For 1 to 60 liter accumulators
Oil port
flange
Mating
flange
Press
Nominal
volume
Model
Nominal
dia.mm
A
B
C d１ d２ T
G
(mm) (mm) (mm) (mm) (mm) (mm)
15（B） 88 45 28 16 22.2 25 M12
1 ∼ 5 OPF-A 20（B） 88 45 28 20 27.7 22 M10
25（１B） 88 48 28 24 34.5 28 M12
15
（
B）
88 45 28 16 22.2 25 M12
20.6
20（B） 88 45 28 20 27.7 22 M10
MPa
25（１B） 88 48 28 25 34.5 28 M12
10 ∼ 60 OPF-B
32（１B）118 56 32 31.5 43.2 28 M12
40（１B）118 65 32 35 49.1 36 M16
50（２B）144 75 40 35 61.1 36 M16
15（B） 88 45 28 16 22.2 25 M12
1 ∼ 5 OPF-C 20（B） 88 48 28 20 27.7 25 M12
25（１B）118 56 32 24 34.5 31 M16
15（B） 88 45 28 16 22.2 25 M12
34.4
20（B） 88 48 28 20 27.7 25 M12
MPa
25（１B）118 56 32 25 34.5 31 M16
10 ∼ 60 OPF-D
32（１B）118 65 32 31.5 43.2 31 M16
40（１B） 144 75 40 35 49.4 39 M20
50（２B）156 84 48 35 61.1 47 M20
◎ Please let us know whether a mating flange is necessary or not.
H
Mating
flange
Standard
G25
G30
G35
G25
G30
G35
G40
G50
G50
G25
G30
G35
G25
G30
G35
G40
G50
G60
NHA15
SHA20
SSA25
NHA15
SHA20
SSA25
SSA32
SSA40
NHA50
NFA15
NFA20
NFA25
NFA15
NFA20
NFA25
NFA32
NFA40
NFA50
Nakamura in-house
standard
Mating
flange
Standard
JIS
B2291
Nakamura in-house
standard
JIS
B2291
Nakamura in-house
standard
For high flow (H type) and 40 to 230 liter accumulators
Oil port
flange
Mating
flange
１
６
●
Press
Nominal
volume
Model
Nominal
dia.
A
B
C d１ d２ T
e
H
(mm) (mm) (mm) (mm) (mm) (mm) (mm)
G
32（１B）φ118 56 44 31.5 43.2 28 16 G40 M12 SSA32
40
（
１
B）
φ
135
65 44 37.5 49.1 36 18 G50 M16 SSA40
20.6
OPF-S 50（２B）φ144 73 44 47.5 61.1 36 20 G60 M16 SSA50 JIS
B2291
MPa
65（２B）φ185 92 45 60 77.1 45 22 G75 M20 SSA65
80（３B）φ200 103 45 71 90.0 45 25 G85 M22 SSA80
10H∼
32（１B）□ 153 110 44 32 43.2 43 18 G80 M24 NHFA32
60H
40（１B）□ 153 110 44 40 49.1 43 20 G80 M24 NHFA40
22.6
in-house
and OPF-H 50（２B）□ 153 110 44 50 61.1 43 23 G80 M24 NHFA50 Nakamura
standard
MPa
□
65（２B） 153 110 44 64 77.1 43 28 G80 M24 NHFA65
40∼
80（３B）□ 153 110 44 71 90.0 43 31 G80 M24 NHFA80
230
32（１B）□ 176 116 45 32 43.2 44 18 G65 M27 NHFA32J
40（１B）□ 176 116 45 40 49.1 44 20 G65 M27 NHFA40J
34.4
in-house
OPF-J 50（２B）□ 176 116 45 50 61.1 44 23 G65 M27 NHFA50J Nakamura
standard
MPa
□
65（２B） 176 116 45 56 77.1 44 28 G65 M27 NHFA65J
80（３B）□ 176 116 45 56 90.0 44 31 G65 M27 NHFA80J
◎ Please let us know if you need the product in other standard such as ASME, API, JPI, DIN etc.
or specify the material.
Title:中村工機-P09∼17.ec6 Page:17 Date: 2014/12/15 Mon 09:21:37
BAB Series
HYDRO-LUNG
■ Features :
Directional control valve
●Preventing pollution of the hydraulic fluid
●Preventing evaporation of hydraulic fluid such
as water glycol
Breather
HU
oil level on
cylinder ascent
How to select the model
HL
（1）Calculate the max displacement of the hydraulic fluid
oil level on
cylinder descent
in the oil reservoir
π
Vk = d2s・10−6
4 Vk : Max displacement of hydraulic fluid ()
d : Diameter of the piston rod (mm)
s : Cylinder stroke (mm)
（2）
Calculate the max flow rate at the time of the displacement (Vk).
Vk Q0 = ・60
Tc Q0 : Max flow rate (/min)
Tc : Operating time of the cylinder (sec)
（3）Comparing the calculated max flow rate with the
allowable flow rate, decide the selection method of the accumulator.
Q0 ≦ Q
Q : Max allowable flow rate (/min)
Hydro-Lung
Fig.1 Example of Hydro-Lung use
Fig.2 Breather
As a result, when Qo is less than Q, it is needed to select a hydro-lung which maximum displacement is adequate to
Vk (Ref. the below model list). But if Qo is more than Q it is better to increase the number of hydro-lungs.
As Fig. 1 Example of Hydro-Lung use, the oil level changes at the same amount as the piston rod volume according to
the hydraulic cylinder operation. At the same time, Hydro-lung absorbs the rise and fall in the air chamber. In other
words, the bladder of Hydro-lung expands along with increase of the oil-level and constricts according to decrease of the
oil-level.
Because a breather valve is equipped, Hydro-lung is effective at the situation also where the oil level greatly changes
due to supplying operation oil or replacing devices.
Concretely speaking, the bladder of Hydro-lung constricts along with decrease of the oil-level. After that, the bladder
absorbs atmosphere from the vacuum valve ② via filter ③ . Conversely, the bladder expands along rise of the oil level
or along increase of the pressure in the air chamber. After that, the air discharges to outside through the relief valve ①.
In addition, Hydro-lung can prevent the oil reservoir from the contamination due to external atmosphere since the
inside is isolated from the outside.
Breather
Rc3/4 to tank
Model
BAB 1
BAB 2.5
BAB 4
BAB 10
BAB 20
BAB 30
BAB 50
Max volume of
breath
()
0.8
1.6
2.4
6.0
11.7
21.0
32.0
Max allowable
flow rate Q
(/min)
47.1
47.1
47.1
152.6
152.6
152.6
152.6
A
(mm)
B
(mm)
C
(mm)
D
(mm)
Mass
(kg)
167
355
225
376
666
1187
1673
384
572
442
635
925
1446
1932
217
217
217
259
259
259
259
114.3
114.3
165.2
216.3
216.3
216.3
216.3
6
9
10
16
24
38
52
Max W.P.
(MPa)
0.03
１
７
●
Title:中村工機-P18∼21.ec6 Page:19 Date: 2014/12/15 Mon 09:26:46
Accumulator stand
We design and manufacture accumulator stands that several accumulators are put together on in addition to supplying
a single accumulator.
Accumulator stands equipped with not only accumulators and the piping but also stop valves, pressure gauges,
pressure switches, other hydraulic devices and stainless steel pipes can be provided.
For example, the accumulator stand with deck stand is designed to check the gas pressure or to maintain the
accumulator safely and the accumulator stand with adjusting bolts is designed to replace bladder and maintain the
accumulator assembly without using hanging tools or machines such as cranes.
The accumulator stand is completely made-to-order, so it is possible to design it in single line, double lines or etc. as
customer demand in consideration of customer's installation space.
● Following pictures are sample model.
1８
●
Title:中村工機-P18∼21.ec6 Page:20 Date: 2014/12/15 Mon 09:26:47
Accumulator stand photos supplied in past
Accumulator stand with 12 sets of 220L accumulator
Accumulator stand with 10 sets of 230L accumulator
(31MPa)
(17MPa)
Accumulator stand with 4 sets of 120L accumulator
Gas cylinder stand with 8 sets of pressure vessel for N2
(1MPa)
gas (20MPa)
１
９
●
Title:中村工機-P18∼21.ec6 Page:21 Date: 2014/12/15 Mon 09:26:48
PA Series
Piston type accumulator
We started to produce piston type accumulators with our own technology in 1967 and after 3 years, ones of 150 liter
was supplied to Nippon Steel Corporation Oita factory for their slab continuous casting machine.
Since then they have been widely used by many customers and applications such as the Ministry of Defense in Japan,
power plants, hydraulic controls, etc.
■Model symbols :
■ Features :
PA 230 − 20 − 20 − LS
Because low friction packing is used, the slide
friction is small.
With a sensor
There is no limitation in the ratio between N2 gas
Seal materials…20. (NBR) for mineral oil
precharge pressure and hydraulic pressure.
28. (FKM) for Phosphate ester
Large gas volume type and High pressure type
Nominal gas volume of the accumulator ()
can be provided.
Max working pressure
Piston type accumulator
Dimensions Max W.P.
Model
PA230−20
−40
−60
−100
(MPa)
22.6
Gas Volume Mass
()
20
40
60
100
(㎏)
160
220
490
605
A
(mm)
953
1562
1380
1860
B
(mm)
C
(mm)
D
(mm)
2
241.8
16
355.6
87
E
(mm)
36
F
Standard size is φ49.1
(40A) or less.
Please letus know if it is
50A or more as special.
◎ Please let us know the use condition and the operating fluid.
◎ As a special specification, large flow rate type can also be provided.
◎ The accumulator with ASME stamp, CE (PED) mark or Chinese certification can be manufactured.
◎ The accumulator available to flame retardancy oil or chemical fluid can be provided.
２
０
●
◎ Equivalent accumulator to cleanliness class NAS6 can be provided.
Max
flow rate
(/min)
990
2200
Title:中村工機-P18∼21.ec6 Page:22 Date: 2014/12/15 Mon 09:26:49
Piston type accumulator
with a sensor
LS Series
A sensor is being installed inside the piston type accumulator to
comply with hydraulic systems electronically controlled, and it outputs
Controller
electric signals continuously and detects the position of the piston of
Output signal
the accumulator.
■ Features :
Power
source
Detecting the position of the piston continuously.
Because the available discharge amount can be confirmed by
detecting the piston position, it is possible to forecast the
maintenance inspection time.
The sensor is placed at a non-pressurized area, so the life is long.
Because the sensor is absolute type, Zero-point setting and Zeropoint correction are not necessary.
Output signal complying to voltage and current is analog, so the
piston position can be easily detected.
The output signal can be indicated in a digital counter and the signal
data fetched to personal computers can be utilized to high level
control system.
A high level control is achieved by using the sensor in combination
with a pressure transducer.
It is possible to measure fuel discharge amount in detail.
A sensor can be applied to all piston type accumulator (Ref. P20).
Example 1
Example 2
Power source
Power source
Controller
ACC
Voltmeter
or
Ammeter
Controller
ACC
In case of
analog output
A/D converter
Digital counter,
personal computer,
etc.
In case of digital output
２
１
●
HYB Series
N2 ɡas booster
N2 gas booster has high energy saving effect. Our piston type accumulators that have a long application history and
high reliability that we are proud of are being installed in it as an compressor.
■ Features :
◦ Compact portable type
◦ Low noise
◦ Small power consumption
◦ Cooling water is not required.
◦ Easy maintenance with simple structure
◦ Less expensive than conventional compressors
Circuit diagram
N2
t°
22
HYB Series
N2 ɡas booster
ES Type
■ Model symbols :
HYB 10 − ES 2 − 24 − 7.5 × 220V
Power source voltage ( ※ Please offer this infomation in advance.)
Electric motor output (kW)
Maximum N2 gas generating pressure (MPa)
(Max W.P of Hyd. pump Minus 1.5)
Design number
Type
ES:Electrical control type
Booster (Compressor) volume (ℓ)
Hydraulically driven booster unit
Reference information from proven specification (Standard model)
Specification
Motor output/cycle
Max generated gas pressure
Booster Unit
Dimensions
Mass
Max working pressure
Hydraulic
Delivery
Pump
Revolution
Type
Compressor
Volume
Model
kW/Hz
MPa
mm
kg
MPa
ℓ/min
rev./min
ℓ
ES
7.5/60 (7.5/50)
24
750 × 1160 × 1590
600
25.5
10.6
1800 (1500)
Piston type
10
Note: This product is not suitable for long time continuous operation because this is for
charging N2 gas into our standard accumulator.
If you intend to use this product in other purpose than the above, please let us know
before you order.
23
FHN Series
Accumulator Stop Valve
Ever since we started to distribute FHN series as accumulator stop valve in 1985, this product is well-known for many
achievements and the reliability.
■ Features :
◦ Compact design with small number of components.
◦ Directly connecting to an accumulator is possible.
◦ Balance structure and a bearing make operation to open and shut easy even at high pressure.
◦ It can be used both as a stop valve and a throttle valve.
◦ Chattering will not occur because the main valve is being screwed to the valve rod.
◦ By using an accumulator joint, the bladder can be replaced without removing an accumulator from the system.
◦ Stainless steel (SUS304) type can be provided.
FHN32S ＆ FHN65S
Model
FHN32L
Dimension d A B C D E F G H I J K L M N P Q R Applicable
(㎜) (㎜) (㎜) (㎜) (㎜) (㎜) (㎜) (㎜) (㎜) (㎜) (㎜) (㎜) (㎜)
(㎜) (㎜)
(㎜) accumulator
FHN32S
FHN65S
FHN32L
Remarks
Connect to
OPF-E-40
Connect to
φ56 320 200 120 153 80 114 − 210 − 48 98 38 G¼ 88 110 M24 122.0
OPF-H
HF＆40〜
Connect to
230ℓ
φ30 217 111 106 104 52 77 104 154 50 48 70 18 G¼ 88 − − 55.5
accumulator
directly
Max W.P.
(MPa)
φ30 217 111 106 104 52 77 − 155 − 48 70 18 G¼ 88 75 M16 55.5 10〜60ℓ
34.4
※OPF-E and OPF-H are special type flange.
※If FHN65S is applied to accumulators with 10 to 60ℓ capacity, it is
connected to OPF-E-40 by using a spacer additionally.
※When the accumulator is connected to a drain port, two kinds
of joint of a bite type joint and a weld type joint are our standard
selection (Ref. pictures at right side). Please specify either of them
as you place an order.
Bite type fitting (K)
24
Weld type fitting (W)
FHN Series
Accumulator Stop Valve
Circuit diagram :
ACC
To drain port (G1/4)
To main port
■ Model symbols
FHN 32 S − 20 − N − F1-1/4B − K − S7
Mark for NAS cleanliness class.
If standard (not required the class), no mark.
Connection parts to a drain port
N : No mark (prepared by customer)
K : Bite type pipe joint
W : Weld type pipe joint
Connection parts to a main pipe
N : No mark (connecting to a inline block arranged separately)
F1-1/4B : Weld type mating flange (Connection size shall be written after“F”.)
Connection parts to an accumulator
N : No mark
◦ In case where FHN32L is applied.
◦ In case where a mating flange (standard) or an accumulator joint is applied.
Seal parts material
20 : NBR
※T he standard connecting way is to use a
28 : FKM
mating flange.
Connection measure
However this time, we would like to show
S : Connecting to a flange
the way to connect an inline block by using
L : Connecting directly to an accumulator
below picture.
The port size of the stop valve
Accumulator stop valve
Example of use:
Connection by OPF
Direct Connection
to accumulator
Connection by an accumulator joint
25
Hiɡh Pressure Gas
Cylinder
We design and manufacture high pressure gas cylinders by taking advantage of the proven know-how that we have
cultivated in accumulator manufacturing. Concretely speaking, cylinders we supplied is 1 to 500 liter in capacity and the
max pressure is 49MPa. The material of cylinders is not only carbon steel but also stainless steel.
The cylinder has many uses, for example, it has been used successfully as a receiver tank for piston type accumulator
or as pressure vessel of various gases. If the cylinder is used as a receiver tank, it is possible to provide the unit
composed by a piston type accumulator and the cylinder.
The cylinder complying with the Designated Equipment Inspection Regulation of High Pressure Gas Safety Act can be
supplied. And it is also possible to provide cylinders designed by ASME or by various classification survey.
Note:
1. The high pressure gas cylinder is different from the vessel under the Cylinder Safety Regulations of High Pressure
Gas Safety Act.
2. This product is completely made-to-order, so it is possible to design it as customer demand.
26
NAKAMURA KOKI REQUEST FORM for selecting accumulator
Date:
Your company name
Tel
E-mail
Contact person
System name・Installation position
Intended use of accumulators
A. Energy Storage
B. Pulsation Damping C. Surge Absorption
□ Bladder Type
A rubber bag is used to separate N2 gas from liquid. It is used to variety applications such as energy storage by accumulating and discharging energy, pipe pulsation absorption, surge absorption and etc. Our accumulators, not only bladder
type but also piston type, are of help in energy saving and improving equipments.
□ Piston Type
A piston is installed to separate the pressurized liquid and the gases. This accumulator is reliable without sudden accidents such as the bladder damage.　The
especial difference to the bladder type is that a super large capacity model and ultra-large flow model can be manufactured in this piston type.
Type of Accumulators
D. Other
Please fill out 1 ～ 4 for the accumulator selection.
1. Inspection, Standard, etc. 2. Operating Condition
□ Unnecessary
（Nakamura Koki internal standards）
3. The Bladder Material
MPa
Normal Working Pressure
Material
Used Fluid
Temperature range
□ High Pressure Gas Safety
Act in Japan
Design Temperature
℃
□ 10（NBR）Nitrile rubber
For low temperature
-25 ～ +  80℃
Normal Working Temperature
℃
□ 20（NBR）Nitrile rubber
Mineral oil, Water glycol
-10 ～ +  80℃
□ ASME
Working Temperature Range
～　℃
□ 30（CHC）Epichlorohydrin
Gasoline・Aromatic material
-10 ～ +  90℃
□ China standard
Working Fluid
□ 40（IIR）Butyl rubber
Phosphate ester
-10 ～ +  90℃
□ CE-MARK
Installation Site
□ Indoor
□ Outdoor
□ 28（FKM）Fluorine rubber
Chemical material, etc
-  5 ～ +120℃
□ Others（
） Installation Direction
□ Vertical
□ Horizontal
※ If the material of rubber is unknown, please let us know the
working fluid and the working temperature range.
4. Specification（a ～ e）
a. Connecting parts in the oil side
b. Parts/device in the gas side
c. Safety device
e. Paint
□ Bushing
Connection threaded port size
[
□ Coreless type gas valve
（Nakamura Koki Standard）
□ Melting Plug
（Nakamura Koki Standard）
□ Unnecessary（Parkerizing）
□ Rupture Disk Type
□ Nakamura Koki Standard
Undercoating：Synthetic resin
Final coating：Phthalic acid resin
Paint color：Munsell N7
（JPMA color codes N-70）
]
□ Oilport flange model name（Ref. P16）
]
[
Mating Flange [ applied・not-applied ]
□ Oilport Flange’s Standard and the size
]
[
□ Without connection parts
□ Others [
]
□ Core type gas valve
□ Coreless Type Gas Port
Pressure Gage Unit
[
□ Special
[
]
]
d. Name Plate
□ N a k a m u r a K o k i S t a n d a r d
Name Plate
□ Flange（Standard name・size）
[
] □ Specified Name Plate
（Please attach specifications）
□ Special
（Please attach specifications）
※ Other special specifications :
Please select the intended use of accumulators from A ～ D and fill in the blanks.
A. Energy Storage
Available Discharge
Volume of Acc.
B. Pulsation Dampening
ΔV
□ Plunger
ℓ
Pump Type
Max Working
Pressure
P3
MPa
Min Working
Pressure
P2
MPa
Average Working Pressure
Precharge Pressure
P1
MPa
Setting Pulsation Rate
Discharge Time
Tn
sec
Charge Time
Tm
sec
Required Discharge
Flow.
Q
ℓ/min
C. Surge Absorption
□ Diaphragm
□ vane
[
]cylinder
□ Single acting
□ Double acting
□ gear
Px
-
Normal Working
Pressure
PA
MPa
Max Allowable
Pressure
PB
MPa
Precharge Pressure
P1
MPa
Fluid Density
ρ
kg/m³
MPa
Inside Diameter of
Pipe
d
mm
Length of Pipe
L
m
Flow Rate of Fluid
Q
ℓ/min
□
MPa
％
Max Allowable Pressure
Pm
Precharge Pressure
P1
MPa
Pump Delivery
Q
ℓ/min
Revolution of Pump
N
rpm
※ D.Other
※ CAD data and the capacity calculation program, you can be downloaded from our web site.
Our entry column
Recommended Model
Notices
Sales office・the person in charge
Selection Date
27
NAKAMURA KOKI CALCULATION FORM for energy storage
Date:
System Name・Use Place
◎ Please use the absolute pressure in the calculation（Absolute pressure（MPaA）= Gauge pressure（MPaG）+ 0.1 ）
.
Available Discharge Volume of Acc.
ΔV
ℓ The discharge in the pressure change from P3 to P2.
Max Working Pressure
P3
MPaA The maximum pressure when the fluid accumulates
Min Working Pressure
P2
MPaA The minimum pressure when the fluid discharges
Precharge Pressure
P1
MPaA ①
Average Working Pressure
Px
MPaA （ P3 + P2 ）/ 2
Discharge Time
Tn
sec Time to discharge the fluid by Δ V liter from the accumulator
Charge Time
Tm
sec Time to accumulate the fluid by Δ V liter to the accumulator
Polytropic Exponents at Discharge Time
n
Polytropic Exponents at Charge Time
m
Accumulator Gas Volume
V1
① Calculation for determining the
precharge pressure value
②
ℓ ③
b. W
hen there is temperature change, the below
formula is applied.
a. P1 = 0.9 × P2（ Min working pressure）
273+Mi n temprature
（℃）
working pressure）
2
P1 ＝ ×0.9 × P（Min
273+Max temprature（℃）
※ Please apply the value of a or b.
The precharge pressure range : 0.25 × P3 ≦ P1 ≦ 0.9 × P2
◎ If the precharge pressure is higher than the value calculated at the above, accumulator capacity becomes smaller
but it is not recommended because the life span of the bladder becomes shorter.
② Polytropic Exponents
Check the discharge time（Tn）, the charge time（Tm）and the average working pressure（Px）and confirm the
polytropic exponent at discharge time（n）from the graph shown in page 3. The polytropic exponent for charge time
（m）is n- 0.2.
（ To compensate the shortage of gas volume（V1）,the value of m is 0.2 less than the value of n.）
Ex. P2 = 16.1MPaA P3 = 21.6MPaA Average working pressure=18.85MPaA
If Tn is 1.5sec, "n" is confirmed as 1.85 by the graph shown in page 3.
If Tm is 120sec, "m" is confirmed as 1.48-0.2=1.28 by the graph shown in page 3.
※ In the case of isothermal change, n = m = 1.
※ In the case of n < m, make the value of "n" same as "m".
※ If the value of m is unclear because the change time is not fixed, we recommend to make the value of m as one
（1）
to put flexibility into the capacity.
③ Accumulator Gas Volume
Calculation Formula
<Energy Storage>
V1＝
ΔV×P2× P3
P2
1
ｍ
（　）
1
n
－1
（　）
｛　｝
P
P1×
P3
2
＝
ℓ×
MPaA
｛
MPaA
×
MPaA
×
（
MPaA
MPaA
（
1/
）
MPaA
1/
）
ℓ
＝
－1
｝
※ A distinctive idea such as "Gross efficiency of accumurator" defined in other maker's own right is not included in
our calculation formula.
Calculation Example
Assume that we select accumulator being installed in hydraulic pressure pipe line as energy storage. By using the
following calculation, we confirm the accumulator gas capacity and confirm the max allowable discharge flow. The
detailed specification is shown in the below table.
Conditions Precedent: Discharge time = 1.5 sec, Charge time = 120 sec, Ambient Temperature = 26 ℃ , Temperature
during operation = 50 ℃
Available Discharge Volume of Acc.
ΔV
Max Working Pressure
P3
Min Working Pressure
P2
Preharge Pressure
P1
Polytropic Exponents at for discharge
n
time
Polytropic Exponents at charge time
m
※ Refer to the polytropic exponents in ② Ex.
3.7ℓ
21.6 MPaA
16.1 MPaA
13.4 MPaA
1.85
1.28
Precharge pressure（P1）:
273 ＋ 26
P1 ＝——————× 0.9 × 16.1 ＝ 13.4MPaA
273 ＋ 50
Accumulator gas volume（V1）:
V1 ＝
ΔV×P2× P3
P2
1
ｍ
（　）
1
n
21.6
＝
－1
（　）
｛　｝
P
P1×
P3
2
3.7 × 16.1 ×（ 16.1
｛
13.4 × （
21.6
16.1
1/1.28
）
1/1.85
）
－1
＝32.5ℓ
｝
Confirmation of maximum allowable discharge Flow（Qmax）
Qmax＝
3.7ℓ×60
ΔV×60
＝
＝ 148ℓ/min
Tn
1.5sec
From the above calculation, the required accumulator's function is that the accumulator gas volume（V1）is 32.5ℓ
or more and the maximum allowable discharge flow is 148 ℓ/min.　In the case, the recommended accumulator
model is G/T230-30.
Please select the accumulator model from this catalogue in consideration of the maximum working pressure（P3）, the accumulator gas volume（V1）and the
maximum allowable discharge flow（Qmax）
28
NAKAMURA KOKI CALCULATION FORM for pulsation damping
Date:
System Name・Use Place
◎ Please use the absolute pressure in the calculation（Absolute pressure（MPaA）= Gauge pressure（MPaG）+ 0.1 ）
Pump Type
Average Working Pressure
（　）cylinder [ Single acting・Double acting ]
Px
F1：Pump Coefficient
MPaA Average pressure of the liquid
Max Allowable Pressure
Pm
MPaA Maximum pressure of the liquid
Precharge Pressure
P1
MPaA ①
Pump Delivery
Q
ℓ/min -
Revolution of Pump
N
rpm -
Pump Type
Simplex
Duplex
Pump Delivery per Revolution
q
Polytropic Exponent
n
②
Pump Coefficient
F1
From table shown on the right hand
Accumulator Gas Volume
V1
① Calculation for determining the
precharge pressure value
ℓ/rev q = Q（Pump delivery ）/ N（Revolution of pump ）
Quintuple
a. P1 = 0.6 × Px（Average working pressure）
0.60
Double acting
0.25
Single acting
0.25
Double acting
0.15
Single acting
0.13
Double acting
0.06
Single acting
0.10
Double acting
0.06
Single acting
0.06
Double acting
0.02
b. When there is temperature change, the below formula is
applied.
273+Min temprature（℃）
P1 ＝ ×0.6 × Px（Average working pressure）
273+Max temprature（℃）
Check the average working pressure（Px）and confirm the polytropic exponent from the graph shown in page 3.
Please contact our sales office if you have any questions.
③ Gas Volume Calculation Formula
of the Accumulator
<Pulsation Damping>
Quadruplex
ℓ ③
※ Please apply the value of a or b.
② Polytropic Exponents
Triplex
F1
Single acting
V1＝
Px
ℓ/min
1
rpm
（　）
P
q×F1×
Px
1
n
（　）
P
1－
m
＝
× 1－
（
MPaA
×（
MPaA
MPaA
）
1/
ℓ
＝
）
MPaA
※ A distinctive idea such as "Gross efficiency of accumurator" defined in other maker's own right is not included in
our calculation formula.
Calculation Example
Assume that we control the pump pulsation within 3% of the average working pressure. By using the following
calculation, we confirm the accumulator gas capacity. The detailed specification is shown in the below table.
Pump type：Plunger Pump Simplex Single acting
Average Working Pressure
Px 5.1  MPaA
Max Allowable Pressure
Pm 5.25 MPaA
Precharge Pressure
P1
3.1  MPaA
Pump Delivery
Q
32 ℓ/min
Revolution of Pump
N
62 rpm
0.60
Pump Coefficient
F1
Polytropic Exponent
n
1.51
Accumulator gas volume（V1）
V1＝
Px
（　）
P
q×F1×
1
Px
Pm
1
n
（　）
1－
＝
5.1
32
× 0.60 ×（ 3.1
62
5.1 1/1.51
1－
（
5.25
）
）
＝ 26.8ℓ
From the above calculation, the accumulator gas volume（V1）
of 26.8ℓ or more is required to control the pressure within
3% of the average working pressure.（In the practical aspect,
※ P olytropic exponent at the average working because the flow velocity and the length of the connecting pipe
pressure 5.1MPaA is determined from the table is involved, it becomes a target value.）
In the case, the recommended accumulator model is G/T175-30.
in page 3.
As to the effects of pulsation dampener, please refer the sample
in page 7.
Please select the accumulator model from this catalogue in consideration of the maximum working pressure（Pm）and the accumulator gas volume（V1）.
29
NAKAMURA KOKI CALCULATION FORM for surge absorption
Date:
System Name・Use Place
◎ Please use the absolute pressure in the calculation（Absolute pressure（MPaA）= Gauge pressure（MPaG）+ 0.1 ）
.
Normal Working Pressure
PA
MPaA Pressure in the pipe where the surge pressure has not been generated.
Max Allowable Pressure
PB
MPaA Maximum allowable surge pressure
Precharge Pressure
P1
MPaA ①
Inside Diameter of Pipe
d
mm
Length of Pipe
L
m
Fluid Density
ρ
kg/m³
Mass of Fluid in Line
M
Flow Rate of Fluid
Q
Flow Velocity
ν
m/sec ④
Polytropic Exponent
n
②
Accumulator Gas Volume
V1
ℓ ⑤
① Calculation for determining the
precharge pressure value
Petroleum-based hydraulic oil
≒ 900 kg/m³
Phosphoric acid ester-based hydraulic oil
≒ 1100 kg/m³
Water ≒ 1000 kg/m³
kg ③
ℓ/min
b. When there is temperature change, the below formula is
applied
a. P1 = 0.9 × PA
273+Min temprature（℃）
P1 ＝ ×0.9 × PA
273+Max temprature（℃）
※ Please apply the value of a or b.
② Polytropic Exponent
Check the normal working pressure（PA）and confirm the polytropic exponent from the graph shown in page 3.
Please contact our sales office if you have any questions.
③ Mass of Fluid in Line（M）
Calculation formula
π
π
－3 2
M ＝　×ｄ2×L×ρ＝　×（ Inside diameter ×10 ）× Length × Fluid density ＝
４
４
④ Flow Velocity（ν）Calculation
formula
⑤ Accumulator Gas Volume
Calculation Formula
<Surge Absorption>
Flow rate
Q
m/sec
υ＝ 21.23 ×　＝
21.23 × ＝
2
2
Inside Diameter
d
V1 ＝
M × v 2 ×（n－1）
n-1
B n
＝
×
kg
2
m/sec
×（　－1）
－1
×（
（　）
｛　｝ 2000 × ｛
P
2000×P1×
P
kg
MPaA
MPaA
A
MPaA
□－1
□
）
ℓ
＝
｝
－1
※ A distinctive idea such as "Gross efficiency of accumurator" defined in other maker's own right is not included in
our calculation formula.
Calculation Example
Assume that we reduce the surge pressure caused by sudden close of the valve that installed at the end of a pipe.
The detailed specification is shown in the below table.
Condition Precedent: External diameter = 8 B × Sch 40 (JIS: 216.3 mm × Thickness 8.2 mm)
Normal Working Pressure
Max. Allowable Pressure
Prechargie Pressure
Inside Diameter of Pipe
Length of Pipe
Fluid Density
Mass of Fluid in Line
Flow Rate
Flow Velocity
Polytropic Exponent
PA
PB
P1
d
L
ρ
M
Q
ν
n
0.85 MPaA
1.35 MPaA
0.75 MPaA
199.9 mm
700 m
900 Kg/m3
19772 kg
4500 ℓ/min
2.4 m/sec
1.407
Mass of Fluid in Line
π
π
－3
2
2
M＝　×ｄ
×L×ρ＝　×
（199.9×10 ）×700×900＝19772 kg
４
４
Flow Velocity
Q
4500
v ＝21.23 × 2.4m/sec
2 ＝ 21.23 × ＝
d
199.92
Gas volume
V1＝
M × v 2 ×（n－1）
n-1
B n
2
＝
19722 × 2.4 ×（1.407 －1）
1.35
－1
（　）
｛　｝2000×0.75×
P
｛（ 0.85 ）
2000×P1×
P
A
1.407－1
1.407
－1
＝ 216ℓ
｝
※ Polytropic exponent at the average working From the above calculation, the accumulator gas volume（V1）is
pressure 1.1MPaA is determined from the 216ℓ or more is required.
table in page 3.
In the case, the recommended accumulator model is TL175-230".
Please select the accumulator model from this catalogue in consideration of the maximum working pressure（PB）and the accumulator gas volume（V1）.
30
Title:中村工機-P31.ec6 Page:19 Date: 2014/12/15 Mon 09:30:00
Safety Precautions for Accumulators
The accumulator is a pressure vessel containing pressurized fluid in it. Read the operation manual and well understand its content before
using the vessel.
To prevent injury to persons or damage to the accumulator, observe the safety precautions below.
1. Selecting an accumulator
！CAUTION : Accumulators are pressure vessels which are controlled under laws and regulations according to their place of use, pressure,
and capacity. When selecting an accumulator, be aware of such regulations.
！CAUTION : Select an accumulator which is compatible with its usage conditions, such as operating pressure, amount of work oil to be
pressurized, operating temperature, type of fluid to be charged in the accumulator, environmental considerations, and
applicable regulations. If a wrong accumulator were selected, it could not only fail to perform to expectations but also
adversely affect interconnected machines.
2. Installing an accumulator
！WARNING＊: Do not attempt to weld any thing to or drill a hole in an accumulator. Such an act would jeopardize its safety and could cause
it to explode.
！CAUTION : Secure an accumulator to the frame or wall with a band or other suitable means. If such a support were neglected, vibration
(due to normal operation or earthquake) would excessively stress the accumulator, and could eventually loosen its fasteners.
！CAUTION : Do not subject an accumulator to external heat.
Put up a heat shield around the accumulator if it is near a heat source or exposed to direct sunlight. If an accumulator were
heated from outside, the fluid inside could build up a dangerously high pressure.
！CAUTION : As a safety measure, provide a pressure control valve in the piping system at a location near and directly connected to the
accumulator so that its maximum allowable pressure will never be exceeded.
3. Charging an accumulator with nitrogen gas (precharging)
！WARNING＊: Only use nitrogen gas as the fluid precharged in an accumulator. Never use oxygen or flammable gas because it could
cause a fire or explosion.
！CAUTION : While no regulatory qualification is required (in Japan) for a person to charge an accumulator with nitrogen gas, it is
important for personal safety that the person be trained for handling high-pressure gases. When charging an accumulator
with nitrogen gas, use a charging assembly which is compatible with the accumulator.
4. Using a charging assembly
！CAUTION : A charging assembly is used for precharging, replenishing, or pressure calibration. Attach a charging assembly to an
accumulator only before use, and always remove it from the accumulator after use. A charging assembly as permanently
attached to an accumulator could increase the possibility of gas leak or damage to its instruments.
5. Using an accumulator
！WARNING : Ensure that an accumulator is used at pressures not exceeding its maximum working pressure (design pressure). Excessive
pressure could cause the accumulator to explode.
！CAUTION : Do not leave an accumulator charged only with pressurized fluid but not with work oil for more than two weeks. Otherwise,
the bladder rubber could permanently stick to the inside surface of the shell.
6. Maintaining an accumulator
！CAUTION : To ensure maximum performance of an accumulator and the integrity of its bladder, check and adjust an accumulator right
after precharging, one week after the precharging, and every three months thereafter. When measuring the pressure of the
fluid in an accumulator, the pressure inside the work oil circuit must be equal to the pressure of the outside atmosphere.
7. Disassembling, reassembling, or discarding an accumulator
！WARNING＊: Reduce the pressure inside the work oil circuit to the pressure of the atmosphere and completely discharge the fluid from
the accumulator before attempting to disassemble it. If you attempted to disassemble it with some pressure inside, you
could be injured by the pressure.
！WARNING＊: Before discharging the fluid from an accumulator, ensure that the area is well ventilated. Otherwise, there could be a
danger of oxygen deficiency. Also ensure that there is no person or objects that could be easily flown away in the direction
in which the fluid is to be discharged. Otherwise, the high-pressure jet of the discharged fluid could injure a person or
damage objects.
！WARNING : After disassembling an accumulator, check and ensure that there is no significantly corroded, scratched, or deformed part in
it before reassembling it. Any degraded part used undetected could endanger the safety of the accumulator.
！CAUTION＊: If a T-series accumulator is disassembled and its bladder is removed off through the top portion, discharge away any fluid
remaining at the bottom before replacing a new bladder. Otherwise, the new bladder could be deformed and damaged by
the buoyancy from the remaining fluid.
！CAUTION＊: When discarding an accumulator, first release both work oil and fluid pressures to the atmosphere, and then disassemble it
and take necessary measures to make it unusable.
Note : The WARNING or CAUTION statements with the word WARNING or CAUTION indicated by the asterisk (＊) above are also marked
on an accumulator in the form of a label.
³
Title:表4のみ.ec6 Page:1 Date: 2014/12/19 Fri 14:12:08
Ever since our company started to deliver bladder type
accumulators in 1962, we do continuously achieve customer
satisfaction by supplying the unique products in high quality
and special technic.
If you have any questions or if we can be of help in any way,
please don't hesitate to let us know.
We are looking forward to do business with you in near future!
〈PRODUCT LINE〉
Bladder type accumulators
Piston type accumulators
Diaphram type accumulators
Accumulator stop valve
Hydro-Lung
N2 gas boosters for charging gas
Accumulators with sensors
In-line type accumulators
O-rings and special packings
(NOTE: There is a possibilly that the contents of this brochure is changed without notice.)
HANGZHOU NAKAMURA KOKI HYDRO TECHNICA CO., LTD.
The factory is approved by CE, AQSIQ (China), METI (Japan), and certified by ASME
(USA), ISO 9001 (Headquarter factory・accumulater)
Headquarter 18-43 Heizaemoncho, Amagasaki-shi, Hyogo-ken 660-0087, Japan
factory Tel:81-6-6419-3791
FAX:81-6-6419-3795
E-Mail : nak@hyd-acc.co.jp
http : //www.hyd-acc.co.jp
Head office: 18-43 Heizaemoncho, Amagasaki-shi, Hyogo-ken 660-0087, Japan
Tel:81-6-6419-7600
FAX:81-6-6419-3795
E-Mail : nakosaka@hyd-acc.co.jp
Tokyo office : 5-7-13-202 Shinbashi, Minato-ku, Tokyo 105-0004, Japan
Tel:81-3-3435-1621
FAX:81-3-3435-1624
E-Mail : naktokyo@hyd-acc.co.jp
Hiroshima office :5-28 Fukuro-machi, Naka-ku, Hiroshima-shi, Hiroshima-ken 730-0036,
Japan
Tel:81-82-248-4093
FAX:81-82-248-4096
E-Mail : nakhiro@hyd-acc.co.jp
Factory in China :22-15-9 Sreet 22 HEAD Hangzhou, 310018 Zhejiang China.
Tel:+86-571-2887-1126
FAX:+86-571-2887-1125
E-Mail : nakchina@hyd-acc.co.jp
14.08A 1000