LFA 50 DBU2A2-7X/400A050/12

Manufacturer: Bosch Rexroth

Material #: R978916349

Model : LFA 50 DBU2A2-7X/400A050/12

***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 DBU2A2-7X/400A050/12 (R978916349) is a sophisticated way cartridge valve designed for pressure functions, suitable for pilot-operated applications in seat or spool designs. This power section of the valve is intended to be installed into a standardized receiving hole according to DIN ISO and is securely closed with a control cover. The model features an integrated pilot control valve for either manual or electrically proportional pressure adjustment, which can be mounted directly onto the control cover or as an external pilot valve with mounting dimensions conforming to DIN standards. This valve enables various pressure functions by combining different cartridge valves with control covers. Specifically, it offers a pressure relief function as a seat valve without an effective area at port B, ensuring that the effective pressure at port A is channeled through the pilot oil supply orifice to the spring side of the element. This allows the spool to remain closed under preset pressures and open when those pressures are exceeded, limiting port A's pressure according to its pressure-flow characteristics. Additionally, it provides a pressure reducing function where in its rest position, it remains open. Similar to the relief function, this spool valve design doesn't have an effective area at port B and uses an identical cover type for pilot control. The spool stays open under set pressures allowing free flow from port B to A until reaching set pressures where it then closes to reduce port A's pressure based on its characteristics. The unit comes in various sizes within component series X and X and can operate at maximum pressures up to bar. It includes options for manual pressure adjustment and can be equipped with directional valves if required. With position indicators 'a' and 'b' for different states of operation, this model ensures precise performance in applications requiring reliable hydraulic blocking (DB function), circulation circuit controls, and efficient management of both pressure relief and reduction functions.

$2,582.00 USD

More are expected on April 25, 2025

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Status: This product is temporarily out of stock.

Qty: Delivered as early as April 25, 2025 when ordered in

This product is eligible for factory repair.

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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"
2 pressure ratings	•	•		4WE6H...	DBmax function	open	DB1 function
			•	4WE10H...		open	DB1 function
	•	•		4WE6D...		DB1 function
			•	4WE10D...		DB1 function

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

01	02	03	04		05		06	07	08
LFA		DBU2A		‒		/

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 2 manual pressure adjustments, electrical selection de-energized - DB1 (4WE.. D) normally open (4WE.. H)	DBU2A 1)
Adjustment type for pressure adjustment (specification only for DB1)
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 DBmax. (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 4)	420
Pressure rating DB1 (observe admissible pressure of the pilot control valve)
07	Set pressure up to 25 bar	A025
	Set pressure up to 50 bar	A050
	Set pressure up to 100 bar	A100
	Set pressure up to 200 bar	A200
	Set pressure up to 315 bar	A315
	Set pressure up to 400 bar	A400
	Set pressure up to 420 bar 4)	A420
Seal material
08	NBR seals	no code
08	FKM seals	V

	1) For set-up of a directional spool valve – see switching symbols
	2) Component series 7X for sizes 16…63.
	3) Component series 6X for sizes 80 and 100.
	4) NG 16 ... 32 only

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

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]		●

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.

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)

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!

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..DBU2A.-7X... NG 16, 25, 32

4 WE 6 D../...

4WE 6 H .. /...

LFA..DBU2A.-7X/... NG 40, 50, 63

4 WE 6 D../...

LFA...DBU2A.-6X/... NG 80, 100

4 WE 10 D../...

4WE 10 H.. /...

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

.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)	*) For DBmax, only adjustment type "2" possible

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"
9	Name plate
10	Lock nut
11	Valve mounting screws M5 x 90 are included in the scope of delivery of the control cover
12	Plug screw M6 conical at ..DBU 2A..
13	Plug screw M6 conical at ..DBU 2B..

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 M5 x 90 are included in the scope of delivery of the control cover
12	Plug screw M6 conical at ..DBU 2A..
13	Plug screw M6 conical at ..DBU 2B..

NG 40, 50

Dimensions in mm

1)	*) For DBmax, only adjustment type "2" possible

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"
9	Name plate
10	Lock nut
11	Valve mounting screws M5 x 90 are included in the scope of delivery of the control cover
12	Plug screw M6 conical at ..DBU 2A..
13	Plug screw M6 conical at ..DBU 2B..

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 M5 x 90 are included in the scope of delivery of the control cover
12	Plug screw M6 conical at ..DBU 2A..
13	Plug screw M6 conical at ..DBU 2B..

NG63

Dimensions in mm

1)	*) For DBmax, only adjustment type "2" possible

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"
9	Name plate
10	Lock nut
11	Valve mounting screws M5 x 90 are included in the scope of delivery of the control cover
12	Plug screw M6 conical at ..DBU 2A..
13	Plug screw M6 conical at ..DBU 2B..

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 M5 x 90 are included in the scope of delivery of the control cover
12	Plug screw M6 conical at ..DBU 2A..
13	Plug screw M6 conical at ..DBU 2B..

NG 80, 100

Dimensions in mm

1)	*) For DBmax, only adjustment type "2" possible

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"
9	Name plate
10	Lock nut
11	Valve mounting screws M5 x 90 are included in the scope of delivery of the control cover
12	Plug screw M6 conical at ..DBU 2A..
13	Plug screw M6 conical at ..DBU 2B..

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 M5 x 90 are included in the scope of delivery of the control cover
12	Plug screw M6 conical at ..DBU 2A..
13	Plug screw M6 conical at ..DBU 2B..

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 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
40	1.2	1.2	1	G1/4	60 -	17	32	27	40	125	69	76	68	47	12
50	1.5	1.5	2	G1/2	68 -	19.5	34	35	50	140	80	84	74.5	54.5	14
63	2.5	2	2.5	-	82 -	55	50	45	-	180	-	-	-	-	-

1)	Orifice Ø, orifice M6 conical

NG	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
80	3.5	3	2.5	250	100	30	45	52	75
100	3.5	3	2.5	300	100	30	51	52	85

1)	Orifice Ø, orifice M8 x 1 conical
2)	Orifice Ø, orifice G 1/4 conical

Configurator / CAD

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Configurator / CAD

General product information on hydraulic products

Installation, commissioning and maintenance of industrial valves

Spare parts & repair

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Spare parts & repair

LFA 50 DBU2A2-7X/400A050/12

Manufacturer: Bosch Rexroth

Material #: R978916349

Model : LFA 50 DBU2A2-7X/400A050/12

More are expected on April 25, 2025

This product is eligible for factory repair.

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

general

hydraulic

LFA..DBU2A.-7X... NG 16, 25, 32

LFA..DBU2A.-7X/... NG 40, 50, 63

LFA...DBU2A.-6X/... NG 80, 100

Installation bore and connection dimensions according to ISO 7368

NG16 ... 63

NG 80, 100

NG 16, 25, 32

NG 40, 50

NG63

NG 80, 100

Directional spool valves, direct operated, with solenoid actuation

WE 6...E

Directional spool valves, direct operated, with solenoid actuation

WE 6...E

4/3, 4/2 and 3/2 directional valve with wet-pin DC solenoids

WE 6...E...407

4/3, 4/2 and 3/2 directional valve with wet-pin DC solenoids

WE 6...E...407

Directional spool valves, direct operated, with solenoid actuation

WE 6...E...UR

Directional spool valves, direct operated, with solenoid actuation

WE 6...E...UR

Directional spool valves, direct operated, with solenoid actuation

WE 10...C

Directional spool valves, direct operated, with solenoid actuation

WE 10...C

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