LFA 50 DBW2-7X/400/12

Manufacturer: Bosch Rexroth

Material #: R978912001

Model : LFA 50 DBW2-7X/400/12

***Disclaimer: The following summary contains information gathered from various sources such as product descriptions, technical specifications and catalogs. While efforts have been made to provide accurate details, inaccuracies may occur. It is advised to verify all information by contacting Bosch Rexroth directly.***
The Bosch Rexroth LFA 50 DBW2-7X/400/12 (R978912001) is a sophisticated cartridge valve designed for precise pressure control in hydraulic systems. This model, part of the component series X, X, can withstand a maximum operating pressure of 400 bar. It is engineered to perform both pressure relief and pressure reducing functions, depending on the configuration. For the pressure relief function, this valve operates as a seat valve with no effective area at port B, ensuring that the spool is balanced and held closed by spring force until the set pressure is reached. Once this occurs, the spool opens to limit pressure at port A according to its characteristic curve. In contrast, for the pressure reducing function, it functions as a spool valve with an open rest position and similarly lacks an effective area at port B. The design allows free flow from port B to port A until the set pressure is attained, at which point the spool closes to reduce and maintain desired pressure levels. This model incorporates manual or electrically proportional pilot control valves for adjusting pressures. These pilot valves are either integrated into or mounted on top of the control cover, following DIN standards for mounting dimensions. The versatility of this product is further enhanced by its compatibility with various control covers that enable different pressure functions. The LFA 50 DBW2-7X/400/12 valve also includes options for manual adjustment and can be paired with directional valves in positions 'a' or 'b', facilitating integration into various hydraulic circuits whether they require open or blocked configurations. Its robust design ensures reliable operation in demanding applications where precise hydraulic control is essential.

$1,909.00 USD

More are expected on May 27, 2025

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Status: This product is temporarily out of stock.

Qty: Delivered as early as May 27, 2025 when ordered in

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General

2-way cartridge valves for pressure functions are pilot-operated valves in seat or spool design. The power section designed as cartridge valve (1) is installed into a receiving hole standardized according to DIN ISO 7368 and closed with a control cover (2).

The pilot control valve (4) for manual or electrically proportional pressure adjustment is integrated into the control cover (2) or is installed on the control cover (2) as pilot valve with mounting dimensions according to DIN 24 340.

By combination of cartridge valves with the control covers, different pressure functions can be realized. .

Pressure relief function

The cartridge valve (1) for the pressure relief function (type LC . DB...) is designed as seat valve without area difference (no effective area at port B). The effective pressure at port A is directed via the pilot oil supply orifice (5) to the spring side (6) of the element. Under the pressure set at the pilot control valve (4), the spool (3) is pressure-compensated and closed by the spring force.

On reaching the set pressure, the spool (3) is opened and the pressure at port A is limited according to the pressure-flow characteristics.

Pressure reducing function

Rest position open

The cartridge valve for the pressure reducing function is designed as spool valve without area difference (no effective areas at port B).

As pilot control valve, identical cover types as for the pressure relief function are applied (type LFA..DB...).

The effective pressure at port A is directed via the pilot oil supply orifice to the spring side of the spool. Under the performance limit and the pressure set at the pilot control valve, the spool is pressure-compensated and retained in open position by the spring force to enable free flow from port B to port A.

On reaching the set pressure, the spool is closed and the pressure at port A is reduced according to the pressure-flow characteristics.

	Size			Pilot control valve	manual pressure adjustment
	16 to 32	40 to 63	80 and 100	Pilot control valve	manual pressure adjustment
	•	•	•		with directional valve
• = available					Position "a"	Position "b"
• = available					Position "a"	Position "0"	Position "b"
Directional valve unloading	•	•		3WE6B9-...	open	DB function

	•			M-3SE.6C...
	•	•		4WE6D...	DB function	open

	•			M-3SE.6U...
			•	3WE10B9-...	open	DB function
			•	4WE10D...	DB function	open

open	Circulation circuit
blocked	Cartridge valve is hydraulically blocked
DB function	Pressure relief function

Orifice symbol	Symbol in ordering code
A**	A**	This orifice is designed as screw-type orifice. If an orifice is to be installed, the respective code letter with the orifice Ø in 1/10 mm has to be entered in the type designation. Example: A12 = Orifice with Ø1.2 mm in channel A.
Ø1,2		This orifice is designed as bore. No specifications are made in the type designation. (Orifice Ø in mm)
Z12		This orifice is designed as screw-type orifice. This is a standard orifice. No specifications are made in the type designation. (Orifice Ø in 1/10 mm)

Pilot control valve		Control cover	Maximum operating pressure in bar Y, T			included in type	separate order
Type	Catalog sheet no.	NG	Maximum operating pressure in bar Y, T
Type	Catalog sheet no.	NG	X	at pressure control	static
DBD. 2 K2X/… 1)	upon request	16 to 32	420	depressurized (up to ≈ 2 bar)	315	●
DBD. 6 K1X/… 2)	25 402	40 to 63	400		315	●
DBD. 10 K1X/… 2)	25 402	80, 100	400		315	●
.WE 6 …	23 178	16 to 63	350		[si]210 (=); 160 (~)[/si][/imp]3050 (=); 2300 (~)[/imp]		●
.WE 10 …	23 327	80, 100	315		[si]210 (=); 160 (~)[/si][/imp]3050 (=); 2300 (~)[/imp]		●
M-3SEW 6 …	22 058	16 to 63	420		100		●
M-3SED 6 …	22 049	16 to 63	315		X-40		●
M-3SEW 10 …	22 075	80, 100	420		100		●
M-3SED 10 …	22 045	80, 100	315		X-40		●

Type
01	Control cover LFA	LFA
Size
02	NG 16	16
	NG 25	25
	NG 32	63
	NG 40	40
	NG 50	50
	NG 63	63
	NG 80	80
	NG 100	100
Version
03	With manual pressure adjustment, for electric unloading circuit	DBW 1)
Adjustment type for pressure adjustment
04	Rotary knob	1
	Sleeve with hexagon and protective cap	2
	Lockable rotary knob with scale (H-locking according to automotive standard)	3
	Rotary knob with scale	4
Component series
Component series
05	Component series 70 ... 79 (70 ... 79: unchanged installation and connection dimensions) 2)	7X
05	Component series 60 … 69 (60 … 69: unchanged installation and connection dimensions) 3)	6X
Pressure rating (observe admissible pressure of the pilot control valve)
06	Set pressure up to 25 bar	025
	Set pressure up to 50 bar	050
	Set pressure up to 100 bar	100
	Set pressure up to 200 bar	200
	Set pressure up to 315 bar	315
	Set pressure up to 400 bar	400
	Set pressure up to 420 bar	420
Seal material
07	NBR seals	no code
07	FKM seals	V

01	02	03	04		05		06	07
LFA		DBW		‒		/

Notice:

By combination of a 2-way cartridge valve with a pilot control valve, various valve functions can be realized.

In particular, the following devices come into question in porting pattern form A6 (up to NG 63) and form A10 (NG 80 to 100) DIN 24 340.

Valve mounting screws are included in the scope of delivery of the control cover.

General information on the ordering codes for control covers: Pilot control valves (maximum operating pressure)

Additional preferred types and standard units are specified in the EPS (standard price list).

general

Size	16	25	32	40	50	63	80	100

hydraulic

Size			16	25	32	40	50	63	80	100
Maximum operating pressure 1)		bar	420
Hydraulic fluid			see table
Hydraulic fluid temperature range	NBR seals	°C	-30 … +80
	FKM seals	°C	-20 … +80
Viscosity range		mm²/s	2.8 … 380
Maximum admissible degree of contamination of the hydraulic fluid 2)			Class 20/18/15 according to ISO 4406 (c)

1)	Attention: Observe pmax of the pilot control valves!
2)	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.

Hydraulic fluid		Classification	Suitable sealing materials	Standards
Mineral oil		HL, HLP	FKM, NBR	DIN 51524
Bio-degradable	Insoluble in water	HEES (synthetic esters)	FKM	VDMA 24568
	Insoluble in water	HETG (rape seed oil)	FKM, NBR	VDMA 24568
	Soluble in water	HEPG (polyglycols)	FKM	VDMA 24568
Other hydraulic fluids on request

For applications outside these parameters, please consult us!

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

The characteristic curves were measured with external, depressurized pilot oil return. Due to the internal pilot oil return, the inlet pressure increases by the output pressure present in port B.

manual pressure adjustment

Type LC 16 DB.E… (with seat piston)

manual pressure adjustment

Type LC 16 DB.E… (with seat piston)

manual pressure adjustment

Type LC 16 DB.D… (seat-spool valve)

manual pressure adjustment

Type LC 16 DB.D… (seat-spool valve)

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

The characteristic curves were measured with external, depressurized pilot oil return. Due to the internal pilot oil return, the inlet pressure increases by the output pressure present in port B.

manual pressure adjustment

Type LC 25 DB.E… (with seat piston)

manual pressure adjustment

Type LC 25 DB.E… (with seat piston)

manual pressure adjustment

Type LC 25 DB.D… (with seat-spool piston)

manual pressure adjustment

Type LC 25 DB.D… (with seat-spool piston)

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

The characteristic curves were measured with external, depressurized pilot oil return. Due to the internal pilot oil return, the inlet pressure increases by the output pressure present in port B.

manual pressure adjustment

Type LC 32 DB.E… (with seat piston)

manual pressure adjustment

Type LC 32 DB.E… (with seat piston)

manual pressure adjustment

Type LC 32 DB.D… (with seat-spool piston)

manual pressure adjustment

Type LC 32 DB.D… (with seat-spool piston)

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

The characteristic curves were measured with external, depressurized pilot oil return. Due to the internal pilot oil return, the inlet pressure increases by the output pressure present in port B.

manual pressure adjustment

Type LC 40 DB.E… (with seat piston)

manual pressure adjustment

Type LC 40 DB.E… (with seat piston)

manual pressure adjustment

Type LC 40 DB.D… (with seat-spool piston)

manual pressure adjustment

Type LC 40 DB.D… (with seat-spool piston)

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

The characteristic curves were measured with external, depressurized pilot oil return. Due to the internal pilot oil return, the inlet pressure increases by the output pressure present in port B.

manual pressure adjustment

Type LC 50 DB.E… (with seat piston)

manual pressure adjustment

Type LC 50 DB.E… (with seat piston)

manual pressure adjustment

Type LC 50 DB.D… (with seat-spool piston)

manual pressure adjustment

Type LC 50 DB.D… (with seat-spool piston)

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

The characteristic curves were measured with external, depressurized pilot oil return. Due to the internal pilot oil return, the inlet pressure increases by the output pressure present in port B.

manual pressure adjustment

Type LC 63 DB.E… (with seat piston)

manual pressure adjustment

Type LC 63 DB.E… (with seat piston)

manual pressure adjustment

Type LC 63 DB.D… (with seat-spool piston)

manual pressure adjustment

Type LC 63 DB.D… (with seat-spool piston)

The control covers are equipped with standard orifice fitting – optimized in our test area. Orifice specification in the type key is not necessary. Deviating operating conditions may require respective adjustment of the orifice size. The orifices are designed as screw-type orifices.

Orifice representation in symbol

LFA..DBW.-7X/...NG 16, 25, 32

4WE 6 D../..

3WE 6 B9-../..

M-3SED 6 U../350…
M-3SEW 6 U../420…

M-3SED 6 C../350…

M-3SEW 6 C../420…

LFA..DBW.-7X/... NG 40, 50, 63

4WE 6 D../..

3WE 6 B9-../..

LFA..DBW.-6X/... NG 80, 100

4WE 10 D...

3WE 10 B9...

Installation bore and connection dimensions according to ISO 7368

NG16 ... 63

Dimensions in mm

5	Bore for locating pin (cover pin assembled according to DIN 24 342)
6	Information on porting pattern NG 16: Length L1 (axis x–y bores) is 80 mm
8	Bore for locating pin at function as main pressure relief valve (reposition cover pin for assembly accordingly)

NG 80, 100

Dimensions in mm

5	Bore for locating pin (cover pin assembled according to DIN 24 342)

Mounting screws: Hexagon socket head cap screw according to DIN 912-10.9
Pilot control valve Type	Dimensions	Tightening torque in Nm
Pilot control valve Type	Dimensions	Tightening torque in Nm
M-3SEW 6 …	M5 x 45	8,9
M-3SEW 10 …	M6 x 40	15,5
M-3SED 6 …	M5 x 50	8,9
M-3SED 10 …	M6 x 40	15,5
.WE 6 …	M5 x 50	8,9
.WE 10 …	M6 x 40	15,5

Mounting screws (included in scope of delivery)
Hexagon socket head cap screw according to DIN 912-10.9
NG	Quantity	Dimensions	Tightening torque in Nm
16	4	M 8 x 45	32
25	4	M 12 x 50	110
32	4	M 16 x 60	270
40	4	M 20 x 70	520
50	4	M 20 x 80	520
63	4	M 30 x 100	1800
80	8	M 24 x 120	900
100	8	M 30 x 120	1800

Thread dimensions of orifice
D orifices at type ..DBE.. NG 25 to 63		M8 x 1 conical
Orifices for NG 80, 100		M8 x 1 conical (A, B, P, D) or G 1/4 (X, F)
other installed orifices		M6 conical

NG 16, 25, 32

Dimensions in mm

1	Port X optionally as threaded port
2	Port Y optionally as threaded port
3	Locating pin
4	Adjustment type "2"
5	Adjustment type "1"
6	Adjustment type "3"
7	Adjustment type "4"
8	Space required to remove the key
9	Name plate
10	Lock nut
11	Valve mounting screws are included in the scope of delivery of the control cover

NG 40, 50

Dimensions in mm

1	Port X optionally as threaded port
2	Port Y optionally as threaded port
3	Locating pin
4	Adjustment type "2"
5	Adjustment type "1"
6	Adjustment type "3"
7	Adjustment type "4"
8	Space required to remove the key
9	Name plate
10	Lock nut
11	Valve mounting screws are included in the scope of delivery of the control cover

NG63

Dimensions in mm

1	Port X optionally as threaded port
2	Port Y optionally as threaded port
3	Locating pin
4	Adjustment type "2"
5	Adjustment type "1"
6	Adjustment type "3"
7	Adjustment type "4"
8	Space required to remove the key
9	Name plate
10	Lock nut
11	Valve mounting screws are included in the scope of delivery of the control cover

NG 80, 100

Dimensions in mm

NG	ØD1H7	ØD2	ØD3/(ØD3*) 1)	ØD4H7	ØD5 2)	ØD6	ØD7H13	H1	H2		H3		H4	H5	H6	H7	H8	H9	L1	L2	L3	L4	L5	W	Ro 3)	Ru 3)
NG	mm	mm	mm	mm		mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm
16	32	16	16 25	25	M8	4	4	42.5	56	+ 0.1	43	+ 0.2	20	11	2	20	2	0.5	65 80	46	23	25	10.5	0.05	2	1
25	45	25	25 32	34	M12	6	6	57	72	+ 0.1	58	+ 0.2	25	12	2.5	30	2.5	1	85	58	29	33	16	0.05	2	1
32	60	32	32 40	45	M16	8	6	68.5	85	+ 0.1	70	+ 0.2	35	13	2.5	30	2.5	1.5	102	70	35	41	17	0.1	2	1
40	75	40	40 50	55	M20	10	6	84.5	105	+ 0.1	87	+ 0.3	45	15	3	30	3	2.5	125	85	42.5	50	23	0.1	4	1
50	90	50	50 63	68	M20	10	8	97.5	122	+ 0.1	100	+ 0.3	45	17	3	35	4	2.5	140	100	50	58	30	0.1	4	1
63	120	63	63 80	90	M30	12	8	127	155	+ 0.1	130	+ 0.3	65	20	4	40	4	3	180	125	62.5	75	38	0.1	4	1
80	145	80	80 100	110	M24	16	10	170.5	205	+ 0.1	175	+ 0.4	50	25	5	40	5	4.5	250	200	-	-	-	0.1	4	1
100	180	100	100 125	135	M30	20	10	205.5	245	+ 0.1	210	+ 0.4	63	29	5	50	5	4.5	300	245	-	-	-	0.1	4	1
16	32	16	16 25	25	M8	4	4	42.5	56	+ 0.1	43	+ 0.2	20	11	2	20	2	0.5	65	46	23	25	10.5	0.05	2	1
25	45	25	25 32	34	M12	6	6	57	72	+ 0.1	58	+ 0.2	25	12	2.5	30	2.5	1	85	58	29	33	16	0.05	2	1
32	60	32	32 40	45	M16	8	6	68.5	85	+ 0.1	70	+ 0.2	35	13	2.5	30	2.5	1.5	102	70	35	41	17	0.1	2	1
40	75	40	40 50	55	M20	10	6	84.5	105	+ 0.1	87	+ 0.3	45	15	3	30	3	2.5	125	85	42.5	50	23	0.1	4	1
50	90	50	50 63	68	M20	10	8	97.5	122	+ 0.1	100	+ 0.3	45	17	3	35	4	2.5	140	100	50	58	30	0.1	4	1
63	120	63	63 80	90	M30	12	8	127	155	+ 0.1	130	+ 0.3	65	20	4	40	4	3	180	125	62.5	75	38	0.1	4	1
80	145	80	80 100	110	M24	16	10	170.5	205	+ 0.1	175	+ 0.4	50	25	5	40	5	4.5	250	200	-	-	-	0.1	4	1
100	180	100	100 125	135	M30	20	10	205.5	245	+ 0.1	210	+ 0.4	63	29	5	50	5	4.5	300	245	-	-	-	0.1	4	1

1)	Due to the use of a bore with ØD3, port B protrudes over the upper limit of the area intended in ISO 7368. This is, however, possible due to the sealing concept and reduces the pressure loss during flow through the valve. Thus, we recommend a bore with ØD3.
2)	Mounting thread for version "/12" see data sheet 08936
3)	Maximum dimension

Notice:

The dimensions are nominal dimensions which are subject to tolerances.

NG	Ø Orifice P** 1)	Ø Orifice X** 1)	Ø Orifice F** 1)	Ø Orifice D** 1)	H1	H2	H3	H4	H5	L1	L2	L3	L4	L5	L7
NG	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm
16	1	0.8	1	0.8	40	17	15	19	28	65	80	36.5	32.5	35	17
25	1	0.8	1	0.8	40	19	24	19	28	85	85	49	45.5	36	27
32	1	1	1.2	1	50	26	28	26	37	100	100	56.5	53	57	34.5

1)	Orifice Ø, orifice M6 conical

NG	Ø Orifice A** 1)	Ø Orifice P** 1)	Ø Orifice F** 1)	Ø Orifice D** 1)	D1	H1	H2	H3	H4	H5	▢ L1	L3	L4	L5	L7	T1
NG	mm	mm	mm	mm		mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm
40	0.8	1.2	1.2	1	G1/4	60	46	32	27	40	125	62.5	76	68	47	12
50	0.8	1.5	1.5	2	G1/2	68	51	34	35	50	140	67.5	84	74.5	54.5	14

1)	Orifice Ø, orifice M6 conical

NG	Ø Orifice A** 1)	Ø Orifice F** 1)	Ø Orifice D** 1)
NG	mm	mm	mm
63	1	2	2.5

1)	Orifice Ø, orifice M6 conical

NG	Ø Orifice A** 1)	Ø Orifice B** 1)	Ø Orifice P** 1)	Ø Orifice X** 2)	Ø Orifice F** 2)	D2	H1	H2	H3	H4	L8
NG	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm
80	1.2	3	3.5	3	2.5	250	100	30	45	52	75
100	1.5	3	3.5	3	2.5	300	100	30	51	52	85