2-WAY CARTRIDGE VALVES, PRESSURE FUNCTIONS

LC..DB (standard)

Material #: R900929152

Model : LC25DB00E7X/V

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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 closed

For the pressure reducing function with opening characteristic, a pressure limitation cartridge valve (type LC..DB40D...) and a control cover with a pressure reducing pilot control valve (type LFA..DR...) are applied. The pilot oil is directed from port A via the supply orifice and the opened pilot control valve to side B.

The main spool is opened and the flow from port A to port B is released.

On reaching the set pressure, the spool is closed and the pressure at port B is reduced according to the pressure-flow characteristics. Potential pressure increases on the secondary side are discharged to the tank via the 3rd way of the pilot control valve. Set-up of a directional valve enables realization of an additional blocking function (type LFA..DRW...).

Pressure sequencing functions

This function enables pressure-dependent connection of a second system.

The required switching pressure is set at the pilot control valve integrated into the control cover.

The pilot oil supply may either be realized externally (pilot oil port X) or internally (from port A via pilot oil ports X or Z2).

The pilot control spring chamber is directed via ports Y or Z1, depressurized to the tank.

Circuit examples

Example 1: (Circuit for pressure-dependent unloading of the low-pressure system)

In the illustrated circuit, the system is supplied via a high-pressure and a low-pressure pump. The system pressure pS acts externally from the high-pressure side via pilot oil port X on the pilot control valve, which sets the low-pressure side to depressurized circulation after the set pressure value is reached. The check valve RV (not included in the scope of delivery) prevents the connection of the high-pressure system with the now depressurized low-pressure system.

On reaching the pressure set at the pilot control spring, the pilot control valve is switched and the spring chamber of the main valve to the tank is unloaded. The main spool is opened and the connection A to B is released.

With the version LFA..DZW..., the required switching position can be selected besides the hydraulic circuit by means of an electrically operated pilot control valve (not included in the scope of delivery of the control cover LFA..DZ...).

Example 2: (Circuit for pressure-dependent connection of a second system)

With this circuit, system 2 is not connected before the pressure in system 1 complies with the specified value. Pilot oil discharge is realized internally from port A of the main valve.

01

02

03

04

05

06

07

LC

DB

/

Type

01

Cartridge valve

LC

Size

02

NG 16

16

NG 25

25

NG 32

32

NG 40

40

NG 50

50

NG 63

63

NG 80

80

NG 100

100

Version

03

Pressure relief function

DB

Cracking pressure

04

Cracking pressure 0 bar (without spring)

00

Cracking pressure approx. 2 bar

20

Cracking pressure approx. 3 bar

1)

30

Cracking pressure approx. 4 bar

40

Cracking pressure approx. 5 bar (NG16, 25 and 32 only)

50

Cracking pressure approx. 8 bar

2)

80

Damping

05

Seat piston without orifice (standard version)

E

Seat spool piston without orifice (standard version)

D

Seat piston without orifice

A

Piston without precision grooves

B

Component series

06

Component series 70 ... 79 (70 ... 79: unchanged installation and connection dimensions)

3)

7X

Component series 60 … 69 (60 … 69: unchanged installation and connection dimensions)

4)

6X

Seal material

07

NBR seals

no code

FKM seals

V

1) Cracking pressure 3.0 bar NG16 only, for set-up of a pilot-operated pressure relief valve type DBC . -5X/…SO187
2) Special installation space required (see compression spring dimensions)
3) Component series 7X for sizes 16...63
4) Component series 6X for sizes 80 and 100

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

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

HETG (rape seed oil)

FKM, NBR

Soluble in water

HEPG (polyglycols)

FKM

VDMA 24568

Other hydraulic fluids on request

hydraulic

Size

16 25 32 40 50 63 80 100

Maximum operating pressure

Port A

bar

420

Port B

bar

420

Maximum flow (recommendation)

Seat-cartridge valve "E" and "A"

l/min

300 450 600 1000 1600 2500 4500 7000

Spool-cartridge valve "D" and "B"

l/min

175 300 450 700 1400 1750 3200 4900

Hydraulic fluid

Mineral oil (HL, HLP) according to DIN 51524; fast biodegradable hydraulic fluids according to VDMA 24568 ; HETG (rape seed oil); HEPG (polyglycols); HEES (synthetic esters), other hydraulic fluids on request

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 1)

Class 20/18/15 according to ISO 4406 (c)
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.

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)

electrically proportional pressure adjustment

Type LC 16 DB.E… (with seat piston)

electrically proportional pressure adjustment

Type LC 16 DB.E… (with seat piston)

electrically proportional pressure adjustment

Type LC 16 DB.D… (seat-spool valve)

electrically proportional 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)

electrically proportional pressure adjustment

Type LC 25 DB.E… (with seat piston)

electrically proportional pressure adjustment

Type LC 25 DB.E… (with seat piston)

electrically proportional pressure adjustment

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

electrically proportional 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)

electrically proportional pressure adjustment

Type LC 32 DB.E… (with seat piston)

electrically proportional pressure adjustment

Type LC 32 DB.E… (with seat piston)

electrically proportional pressure adjustment

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

electrically proportional 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)

electrically proportional pressure adjustment

Type LC 40 DB.E… (with seat piston)

electrically proportional pressure adjustment

Type LC 40 DB.E… (with seat piston)

electrically proportional pressure adjustment

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

electrically proportional 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.D… (with seat-spool piston)

manual pressure adjustment

Type LC 50 DB.E… (with seat piston)

manual pressure adjustment

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

electrically proportional pressure adjustment

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

electrically proportional pressure adjustment

Type LC 50 DB.E… (with seat piston)

electrically proportional pressure adjustment

Type LC 50 DB.E… (with seat piston)

electrically proportional 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)

electrically proportional pressure adjustment

Type LC 63 DB.E… (with seat piston)

electrically proportional pressure adjustment

Type LC 63 DB.E… (with seat piston)

electrically proportional pressure adjustment

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

electrically proportional pressure adjustment

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

Version "E"

Version “D”

Area ratio
A1 : A2 = 2 : 1
Version "…A.E…"

Area ratio
A1 : A2 = 14.3 : 1
Version "…B.E…"

Area ratio
A1 : A2 = 2 : 1
Version "…A.D…"

Area ratio
A1 : A2 = 14.3 : 1
Version "…B.D…"

Installation bore and connection dimensions according to ISO 7368

Dimensions in mm

1

Depth of fit

2

Control dimension

3

If a different diameter is used for port B than ØD3 or (ØD3*), the distance from the cover support surface to the bore center must be calculated.

4

Port B may be positioned around the central axis of port A. However, it must be observed that the mounting bores and the control bores are not damaged.

7

At Ø ≤45 mm → Fitting H8 admissible

NG

ØD1

ØD2

ØD3/(ØD3*)

ØD4

ØD5

ØD6 1)

ØD7

H1/(H1*)

H2

H3

H4

H5

H6

H7

H8

H9

L1

ØL1

L2

ØL2

L3

L4

L5

W

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 H7
-
16 16
25
25 H7
-
M8 4 4 H13
-
34
29.5
56 43 - 20 11 2 20 2 0.5 65
80
- 46 - 23 25 10.5 0.05
25 45 H7
-
25 25
32
34 H7
-
M12 6 6 H13
-
44
40.5
72 58 - 25 12 2.5 30 2.5 1 85
-
- 58 - 29 33 16 0.05
32 60 H7
-
32 32
40
45 H7
-
M16 8 6 H13
-
52
48
85 70 - 35 13 2.5 30 2.5 1.5 102
-
- 70 - 35 41 17 0.1
40 75 H7
-
40 40
50
55 H7
-
M20 10 6 H13
-
64
59
105 87 - 45 15 3 30 3 2.5 125
-
- 85 - 42.5 50 23 0.1
50 90 H7
-
50 50
63
68 H7
-
M20 10 8 H13
-
72
65.5
122 100 - 45 17 3 35 4 2.5 140
-
- 100 - 50 58 30 0.1
63 120 H7
-
63 63
80
90 H7
-
M30 12 8 H13
-
95
86.5
155 130 - 65 20 4 40 4 3 180
-
- 125 - 62.5 75 38 0.2
80 145 H7
-
80 80
100
110 H7
-
M24 16 10 H13
-
130
120
205 175 ± 0.2 50 25 5 40 5 4.5 -
-
250 - 200 - - - 0.2
100 180 H7
-
100 100
125
135 H7
-
M30 20 10 H13
-
155
142
245 210 ± 0.2 63 29 5 50 5 4.5 -
-
300 - 245 - - - 0.2
1) Maximum dimension