PRESSURE CONTROLSLow Noise Type Pilot Operated Relief Valves
Pilot operated relief valves here have been particularly developed as low-noise types. Ableto protect pumps and control valves against excessive pressures, they are used to control
the pressure in the hydraulic system to a constant level.
Remote control and unloading are permitted by using vent circuits.

CMax. OperatingPres.
MPa

Model Numbers

Pres. Adj. Range
MPa

S−BG−03−＊−＊−4025

S−BG−06−＊−＊−40★ - 25

S−BG−10−＊−40

Max. FlowL/minApprox. Masskg

100

4.12005.040010.5

Low Noise Type■ Specifications★ See minimum adjustment pressure characteristics on page C-12.

■ Model Number Designation
S−Low NoiseTypeＳ：Low
NoiseTypeBG

Series Number

Type ofMounting

Ｂ：Pilot
Operated
ReliefValves

Ｇ：Sub-plate
Mounting−03−V

Valve SizeHigh Venting
Pres. Feature★

03
06
10−L

−40

Directionof Handle
V：For High Venting Viewed from pressure
Pressure Feature gauge connection
L: Left (Normal) R: Right(Omit if notrequired)—————（DesignNumber

Graphic Symbols） 4040
40

★ Use the high venting pressure type where it is necessary to reduce the changeover time from unloading to onloading.
We also product The Low Noise Type Solenoid Controlled Relief Valves
as below. For more details, please contact us.
Model Numbers
S−BSG−03−＊−＊−＊−＊−＊−53
S−BSG−06−＊−＊−＊−＊−＊−53
S−BSG−10−＊−＊−＊−＊−53

Max. Operating Max. Flow
Pres. MPa
L/min
100
25200
400

Vent Connection■ Accessories● Mounting Bolts
Valve Model Numbers

Socket Head Cap Screw

S−BG−03

M12×40L …… 4 Pcs.

S−BG−10

M20×60L …… 4 Pcs.

S−BG−06■ Instructions● If a remote control relief valve is used in the vent circuit, see page C-5.
In addition, if the internal volume of the vent line is too large,
chattering is likely to occur. Thus, as far as possible reduce the inside
diameter and the length of the pipe.
● To adjust the pressure, loosen the lock nut and turn the handle slowly
clockwise for higher pressures or anti-clockwise for lower pressures.
After adjustments, do not forget to tighten the lock nut.
● Piping of the tank line should not be connected to any tank line of theother valves, but connected directly to the reservoir.
● With a small flow, the setting pressure may be unstable. Use withminimum flow rate as the table below.
Valve Size
0306
10Min. Flow
5 L/min
8 L/minM16×50L …… 4 Pcs.

■ Sub-plates
Valve ModelNumbers
S−BG−03
S−BG−06
S−BG−10Sub-plateModel Numbers
BGM−03−20

BGM−03X−20
BGM−06−20
BGM−06X−20
BGM−10−20
BGM−10X−20

Thread Size
Rc
3／
81／2
3／
41

1 1／4
1 1／2

Approx.
Mass kg
2.4
3.1
4.7
5.7
8.4
10.3

● Sub-plates are available. Specify the sub-plate model number
from the table above. When sub-plates are not used, the mounting
surface should have a good machined finish. (1.6 )● The sub-plates are those for pilot operated relief valves. For
dimensions, see page C-9.

Low Noise Type Pilot Operated Relief Valves

C-11

03−＊−L−40
S−BG−06
S−BG−10−＊−40

Fully Extended J

Fully Extended
F

Mounting Surface
S−BG−03：ISO 6264−06−09−1−97
S−BG−06：ISO 6264−08−13−1−97
S−BG−10：ISO 6264−10−17−1−97"K" Dia. Through"N" Dia. Spotface
4 Places
Pressure Port

Opposite Handle Position

CE03−＊−R
S−BG−06AB

D★ Pressure is limited by collars fitted. Ifa working pressure cannot be attained,
remove some collars. One collar isequivalent to 10 MPa.

Fully Extended JZ

Tank Port
Pressure Adjustment Handle

Pressure Gauge Connection
Rc 1/4 Thd.

Two Collars★

INC.

Lock Nut
14 Hex.
44 Dia.

P

Vent Port

H

6

Mounting Surface(O-Rings Furnished)

Locating Pin
6 Dia.

VU

Model Numbers

ＡB

C

DEF

HKNPQSTUVXZ

S−BG−03

76

53.8

11.1

26.9

53.8

73.6

26.9 163.5 13.5

215013010321.5

10626.1

1336.1S−BG−1012082.6

18.7

41.3

88.9

46.1

44.9

3265

167

135

33.5

155

21.1

18

S−BG−0698

70

143566.7

58.8

J33.7 163.5 17.5
18060

Flow Rate L/min

80

0100

50

S-BG-03
0.9

Pressure

1.2

Low Vent
Pressure Type

0.2

0.8

4060

150

200

0Hydraulic Fluid: Viscosity : 35 mm²/s
Specific Gravity : 0.850

Flow Rate L/min

80

100

19.3

1321.3——S-BG-10100200300

Flow Rate L/min

400

Vent Pressure
Min. Adjustment Pressure

S-BG-10

1.6High Vent
Pressure TypeMPa 0.4MPaLow Vent Pressure Type020122

S-BG-06

0.60.4100

Flow Rate L/min

1.4High Vent
Pressure Type0.826252423221514
MPa 132.01.51.0Pressure

40103

Pressure

Pressure

Pressure

20■ Min. Adj. Pressure and Vent Pressure vs. Flow

Pressure

130252423151413
MPa 1.5
1.00.50050

S-BG-06

S-BG-03
252423151413
MPa 1.5
1.00.5

MPa

21.5

26

Hydraulic Fluid : Viscosity : 35 mm²/s
Specific Gravity : 0.850■ Nominal Override Characteristics

C-12Note:For dimensions of the valve mounting
surface, see the dimensional drawing(Page C-9) of the sub-plate usedtogether.

XTSQFor other dimensions, seethe figures shown left.

50100150

Flow Rate L/min

200

1.2High Vent
0.8 Pressure Type0.40100

Low Vent Pressure Type

200

300

Flow Rate L/min

Note: Vent Pressure means the relief pressure when the vent part open to the tank line.

Low Noise Type Pilot Operated Relief Valves

400

PRESSURE CONTROLSNoise Level

Noise Level

Flow Rate 50 L/min

7060

dB (A)

Measuring Position : At 1m back from the valve front.

S-BG-0680

Flow Rate 150 L/min

706040704812

Pressure MPa

164020C60500

Flow Rate 200 L/mindB (A)dB (A)

50

S-BG-1080

Noise Level

S-BG-0380

Viscosity : 35 mm²/s

5004812Pressure MPa

1640200481216

Pressure MPa

Low Noise Type

Measuring Condition
Back Pressure : 0.1 MPa■ Noise Level

20■ List of Seals
S−BG−03, 06, 1013 14 22 12 20 1110 26 23 24 157218919223225

19303145

S−BG−10183Item

Name of Parts

2526272829303132O-Ring
O-RingO-RingO-RingO-RingO-RingO-RingO-Ring

176S-BG-03
OR NBR-90 P9-N
OR NBR-70-1 P9-N
OR NBR-90 P9-N
OR NBR-90 P18-N
AS 568-024（NBR-90）
OR NBR-90 P28-N
OR NBR-90 P32-N————————

29 28 16 27

1

Part Numbers
S-BG-06
OR NBR-90 P9-N
OR NBR-70-1 P9-N
OR NBR-90 P11-N
OR NBR-90 P28-N
AS 568-024（NBR-90）
OR NBR-90 P28-N
OR NBR-90 P32-N————————

S-BG-10OR NBR-90 P9-N
OR NBR-70-1 P9-N
OR NBR-90 P9-N
OR NBR-90 P32-N
AS 568-128（NBR-90）
OR NBR-90 P36-N
OR NBR-90 P42-N
OR NBR-90 P14-N

Qty.
21121111■ Interchangeability Between Conventional Type and Low Noise TypeThe 40 design of low noise type S-BG-03, 06, 10 has mounting interchangeability with the 32 design of conventional type BG-03, 06, 10.
But the outside shape is different, for example the direction of pressure adjustment handle.
03
Low noise Type：S−BG−06, 40 Design
10AVent PortETPressure Adjustment Handle
Pressure PortUVAModel Numbers

ＡＢ

ＥＫＮ

BG−06

104

82

53.8

53.8

13.5

21124

82.6

88.9

21.5

32

BG−03

BG−10

70

66.7

17.5

"K" Dia. Through"N" Dia. Spotface
4 Places

B

Tank Port

26ＴＵＶ

117

55

78

175

45

65

141

38

58

B

Vent Port

Fully Extended J

Pressure Port

Pressure Gauge
Connection

Pressure Gauge
Connection"K" Dia. Through"N" Dia. Spotface
4 Places
Tank Port

Fully Extended E
F

44 Dia.

Fully Extended 145

03
Conventional Type：BG−06, 32Design
10W
44 Dia.

Pressure Adjustment
HandleModel Numbers

ＡＢ

Ｅ

ＦＫＮ

Ｊ

S−BG−03
S−BG−06

76

53.8

53.8

73.6

13.5

21163.5 20.5

S−BG−1098120

82.6

88.9

50.6

21.5

32

180

Low Noise Type Pilot Operated Relief Valves

7066.7

58.8

17.5

26

163.5

Ｗ25

32.5

C-13