SV 20 GB1-4X/V/12

Manufacturer: Bosch Rexroth

Material #: R978872250

Model : SV 20 GB1-4X/V/12

$1,259.00 USD

More are expected on September 22, 2025

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Qty	Price	Savings
5+	$1,227.52 USD	$31.48 USD

Status: This product is temporarily out of stock.

Qty: Delivered as early as September 22, 2025 when ordered in

This product is eligible for factory repair.

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For subplate mounting Porting pattern according to ISO 5781-06-07-0-00 (NG10), ISO 5781-08-10-0-00 (NG20), ISO 5781-10-13-0-00 (NG32) For threaded connection For the leakage-free blocking of one actuator port Pilot oil return, internal Version with pre-opening for dampened release, optional Various cracking pressures, optional Check valve installation sets available individually Corrosion-protected design

The isolator valve type SV is a releasable check valve for subplate mounting or threaded connection. It is used for the leakage-free blocking of one actuator port, also in case of longer standstill times.

The valve basically consists of a housing (1), a seat poppet (2), a compression spring (3), a control spool (4) as well as of an optional pre-opening as ball seat valve (5).

The seat valve can be flown through from A to B without external pilot pressure. In the opposite direction, the seat valve closes hydraulically tight.

Condition: pA > pB + cracking pressure (compression spring).

A sufficiently high pilot pressure at port X moves the control spool (4) in the direction of the ball seat valve (5) (version "A") and pushes the seat poppet (2) out of its seat. This allows for a free flow in both directions (active keeping open).

In order to ensure that the seat valve actively opens, the pressure ratios on both sides of the control spool (4) are just as important as the area ratios at the control spool (4) or seat poppet (2).

This results in the versions with pre-opening "A" and without pre-opening "B” for type SV (large annulus area). A3 (8); with pA connected).

Version "A" (with pre-opening)

This valve is provided with an additional pre-opening. By pressurization at the X port, the control spool (4) is moved to the right. As a result, the ball (5) is pushed off the seat first and the seat poppet (2) afterwards.

Notes:

Version "A”: The two-stage set-up with an increased control open ratio means even low pilot pressure can be unloaded securely. Avoidance of switching shocks due to dampened decompression of the pressure volume on the actuator side. Version "B”: In case of valves without pre-opening, the included pressure volume may be unloaded suddenly. Resulting switching shocks may lead to premature wear on installed components, as well as noise formation.

6	Area A1 (seat poppet)
7	Area A2 (ball)
8	AreaA 3 (control spool)
9	Area A4 (control spool)

Notice:

The modification of type SV to type SL is possible by exchange of plugs (10) and (11). One of the both plugs must always be installed.

NG	Plug (10)	Plug (11)
10	M3	M6
20	M4	M6
30	M4	M6

01	02	03	04	05	06		07		08		09	10	11	12	13	14
S	V					–	4X	/		–						*

01	Check valve	S
02	Pilot oil return, internal	V
03	Size 10	10
	Size 20	20
	Size 32	30
Type of connection
04	Subplate mounting	P
04	Threaded connection	G
05	With pre-opening	A
05	Without pre-opening	B
Cracking pressure
06	See characteristic curves (A → B)	1
		2
		3
		4
07	Component series 40 … 49 (40 … 49: unchanged installation and mounting dimensions)	4X
Spool position monitoring
08	Without position switch	no code
	With position switch 1)	QMG24
	For more information see "Electrical connection"
Orifice fitting channel Y
09	Channel Y closed (standard)	Y99
09	Orifice Ø** in channel Y 2)	Y**
Seal material
10	NBR seals	N
	FKM seals	V
	Observe compatibility of seals with hydraulic fluid used. (Other seals upon request)
Corrosion resistance
11	None	no code
11	Improved corrosion protection (240 h salt spray test according to EN ISO 9227)	J3
12	Standard	no code
	Pilot pressure ppilot from channel X	SO168
	Control open spool with shaft sealing (between channel X–Y and Y–A)	SO286
Connection thread (versions with threaded connection "G" only)
13	Pipe thread "G" according to ISO 228-1	no code
13	Pipe thread “UNF/UN” according to ANSI/ASME B 1.1	/12
14	Further details in the plain text	*

1)	Only version "B3"
2)	Order example: ** = dimension in mm x 10 – e.g. orifice Ø1,2 mm in channel Y = "Y12"

general

Size			10	20	32
Weight	Subplate mounting	kg	1.8	4.7	7.8
	Threaded connection	kg	2.1	5.4	10
Installation position			any
Ambient temperature range	NBR seals	°C	-30 … +80
	FKM seals	°C	-20 … +80
MTTFD values according to EN ISO 13849 1)		Years	150
Maximum storage time 2)		Months	12

1)	For further details, see data sheet 08012
2)	If the storage conditions are observed; refer to the operating instructions 07600-B

hydraulic

Size			10	20	32
Maximum operating pressure		bar	315
Cracking pressure		bar	1.5 / 3 / 6 / 10	2.5 / 5 / 7.5 / 10	2.5 / 5 / 8 / 10
Minimum pilot pressure		bar	5
Maximum pilot pressure		bar	315
Maximum flow			See characteristic curves
Direction of flow			Free from A → B, from B → A by opening
Hydraulic fluid			see table below
Hydraulic fluid temperature range	NBR seals	°C	-30 … +80
	FPM seals	°C	-20 … +80
Viscosity range		mm²/s	2.8 … 500
Maximum admissible degree of contamination of the hydraulic fluid, cleanliness class according to ISO 4406 (c) 1)			Class 20/18/15
Pilot volume	Port X	cm³	2.5	10.8	19.27
Control area A1 2)		cm²	1.33	3.46	5.72
Control area A2 2)		cm²	0.33	0.7	1.33
Control area A3 2)		cm²	3.8	10.17	16.61
Control area A4 2)		cm²	0.79	1.13	1.54

1)	The cleanliness classes specified for the components must be adhered to in hydraulic systems. Effective filtration prevents faults and simultaneously increases the life cycle of the components. For the selection of the filters, see www.boschrexroth.com/filter.
2)	Areas according to sectional drawing, see "Product description"

Hydraulic fluid		Classification	Suitable sealing materials	Standards	Data sheet
Mineral oils		HL, HLP, HLPD, HVLP, HVLPD	NBR, FKM	DIN 51524	90220
Bio-degradable	Insoluble in water	HETG 1)	NBR, FKM	ISO 15380	90221
	Insoluble in water	HEES 1)	FKM	ISO 15380
	Soluble in water	HEPG 1)	FKM	ISO 15380
Flame-resistant	Water-free	HFDU (glycol base)	FKM	ISO 12922	90222
		HFDU (ester base) 1)	FKM
		HFDR	FKM
	Containing water	HFC (Fuchs Hydrotherm 46M, Petrofer Ultra Safe 620) 1)	NBR	ISO 12922	90223
Important information on hydraulic fluids: For more information and data on the use of other hydraulicfluids, please refer to the data sheets above or contact us. There may be limitations regarding the technical valve data (temperature, pressure range, life cycle, maintenance intervals, etc.). The ignition temperature of the hydraulic fluid used must be 50 K higher than the maximum surface temperature. Flame-resistant - containing water: Maximum pressure differential 210 bar, otherwise, increased cavitation erosion Life cycle as compared to operation with mineral oil HL, HLP 30 … 100%. Maximum hydraulic fluid temperature 60 °C Bio-degradable and flame-resistant – containing water: If this hydraulic fluid is used, small amounts of dissolved zinc may get into the hydraulic system.

1)	Not recommended for corrosion-protected version "J3" (contains zinc)

For applications outside these parameters, please consult us!

(measured with HLP46, ϑOil = 40 ±5 °C)

Subplate mounting

Δp-qV characteristic curves

Size 10

Δp-qV characteristic curves

Size 20

Δp-qV characteristic curves

Size 32

Pilot pressure/load pressure characteristic curves

Without pre-opening

Pilot pressure/load pressure characteristic curves

With pre-opening

Threaded connection

Δp-qV characteristic curves

Size 10

Δp-qV characteristic curves

Size 20

Δp-qV characteristic curves

Size 32

Pilot pressure/load pressure characteristic curves

Without pre-opening

Pilot pressure/load pressure characteristic curves

With pre-opening

Calculation of the pilot pressure pSt dependent on pA and pB

Version “A” (with pre-opening)
Balance of forces:

Detailed formula

Simplified formula (Assumption pA = 0)

Version "B" (without pre-opening)
Balance of forces:

Simplified formula (Assumption pA = 0)

pA*	Type-dependent (for type SL: pA* = 0)
pSt	Pilot pressure
pA	Working pressure in A
pB	Working pressure in B
pF	Cracking pressure (spring)
A1 – A4	For areas see sectional drawing below "product description" and control area ratios below "technical data"

Pilot oil return, internal

Version "SO168"

Circuit examples

Function: "Load locking"; inlet side unloading

Function: Unlocking with external pilot pressure (version "SO168")

Inductive position switch type QM

The electrical connection is realized via a 4-pole mating connector (separate order, see "Accessories") with connection thread M12 x 1.

Connection voltage:	24 V +30 %/-15 %, direct voltage
Admissible residual ripple:	≤ 10 %
Load capacity:	maximum 400 mA
Switching outputs:	PNP transistor outputs, load between switching outputs and GND
Pinout:	1	+24 V
	2	Switching output: 400 mA
	3	0 V, GND
	4	Switching output: 400 mA

Switching logics

Subplate mounting

Dimensions in mm


Required surface quality of the valve contact surface

1	Port Y closed
2	Name plate
3	Locking pin
4	Identical seal rings for ports A and B Identical seal rings for ports X and Y
5	Valve with cracking pressure Version "1" and "2" (dimension L2)
6	Valve with cracking pressure version "3" and "4" (dimension L3)
7.1	6 valve mounting bores at NG32
8	Porting pattern according to ISO 5781
9	Version without position switch Tightening torque MA = 40 Nm (NG10), screwed in - medium-strength thread locker; Tightening torque MA = 70 Nm (NG20 and 30), screwed in - medium-strength thread locker
10	Version with position switch "QMG24" (circuitry see "Electrical connection")

NG	L1	L2	L3	L4	L5	L6	L7	L8	L9	L11	L12	L13	L14	B1	B2	B3	B4	B6	H1	H2	H3
NG	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm
10	100.8	15.5	15.5	87.8	13	42.9	18.5	7.2	35.8	21.5	-	31.8	105	84	67.7	44	58.8	33.3	51	29	36
20	135	17.7	47.7	117	18	60.3	27.5	11.1	49.2	20.6	-	44.5	96.5	100	79.4	67	73	39.7	81	45	55
32	156.1	36.1	46.1	134	22.1	84.2	39	16.7	67.5	24.6	42.1	62.7	117	118	96.8	75	92.8	48.4	85	42.5	70

Valve mounting screws (separate order)

Size	Quantity	Hexagon socket head cap screws	Material number
10	4	ISO 4762 - M10 x 50 - 10.9 Tightening torque MA = 75 Nm ±20 %	-
20	4	ISO 4762 - M10 x 70 - 10.9 Tightening torque MA = 75 Nm ±20 %	-
32	6	ISO 4762 - M10 x 85 - 10.9 Tightening torque MA = 75 Nm ±20 %	-

Notice:

The specified tightening torques were calculated with total friction coefficient μtotal = 0.09 ... 0.14; adjust in case of modified surfaces.

Subplates (separate order)

with porting pattern according to ISO 5781-06-07-0-00 (NG10), ISO 5781-08-10-0-00 (NG20), ISO 5781-10-13-0-00 (NG32) see data sheet 45100.

Threaded connection

Dimensions in mm

1	Port Y closed
2	Name plate
5	Valve with cracking pressure Version "1" and "2" (dimension L2)
6	Valve with cracking pressure version "3" and "4" (dimension L3)
7.2	2 valve mounting bores
9	Version without position switch Tightening torque MA = 40 Nm (NG10), screwed in - medium-strength thread locker; Tightening torque MA = 70 Nm (NG20 and 30), screwed in - medium-strength thread locker
10	Version with position switch "QMG24" (circuitry see "Electrical connection")

NG	L1	L2	L3	L4	L5	L6	L7	L8	L9	L10	L11	B1	B2	B3	H1	H2
NG	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm
10	100.8	15.5	15.5	87.8	13	56.5	10.5	33.5	22.5	17.3	105	87	66.7	33.4	44	22
20	133	17.7	47.7	115	18	74.5	17	50.5	36	27	96.5	105	79.4	39.7	68	34
32	156.1	35.7	45.7	134	22.1	101	24	84	49	18	117	130	96.8	48.4	85	42.5

Ports

NG	A	B	X	Y
NG	"G"	"UNF/UN"	"G"	"UNF/UN"
10	G1/2	3/4-16 UNF	G1/4	7/16-20 UN
20	G1	1 5/16-12 UN	G1/4	7/16-20 UN
32	G1 1/2	1 7/8-12 UN	G1/4	7/16-20 UN

Valve mounting screws (separate order)

Size	Quantity	Hexagon socket head cap screws	Material number
10	2	ISO 4762 - M10 x 60 - 10.9	-
20	2	ISO 4762 - M10 x 85 - 10.9	-
32	2	ISO 4762 - M10 x 100 - 10.9	-

Connection adapter / reducing pieces

Material number	Male thread	Internal thread	Seal (separate order)
Material number	Male thread	Internal thread	NBR	FKM
R900173685	G1	G3/4	R900012475	R900012509
R900173689	G1 1/2	G1 1/4	R900012477	R900012511

Spare parts & repair

SV 20 GB1-4X/V/12

Manufacturer: Bosch Rexroth

Material #: R978872250

Model : SV 20 GB1-4X/V/12

More are expected on September 22, 2025

View Bulk Pricing Discounts

This product is eligible for factory repair.

general

hydraulic

(measured with HLP46, ϑOil = 40 ±5 °C)

Subplate mounting

Δp-qV characteristic curves

Δp-qV characteristic curves

Δp-qV characteristic curves

Pilot pressure/load pressure characteristic curves

Pilot pressure/load pressure characteristic curves

Threaded connection

Δp-qV characteristic curves

Δp-qV characteristic curves

Δp-qV characteristic curves

Pilot pressure/load pressure characteristic curves

Pilot pressure/load pressure characteristic curves

Calculation of the pilot pressure pSt dependent on pA and pB

Pilot oil return, internal

Version "SO168"

Circuit examples

Function: "Load locking"; inlet side unloading

Function: Unlocking with external pilot pressure (version "SO168")

Inductive position switch type QM

Switching outputs:

Pinout:

Switching logics

Subplate mounting

Valve mounting screws (separate order)

Threaded connection

Valve mounting screws (separate order)

Connection adapter / reducing pieces

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