preenchimento sfa - re20485

1/10

Information on available spare parts: www.boschrexroth.com/spc

Prefill valve

Type SFA

RE 20485/04.08Replaces: 07.06

Table of contents Features

– Pilot operated check valve • for threaded connection (sizes 25 and 32) • for flange connection to ISO 6162-1 (from size 40)

– For direct mounting onto a working cylinder – With or without pre-decompression, optional– Integrated high-pressure port

H6714

Inhalt SeiteFeatures 1Ordering code 2Symbols 2Function, section 3Technical data 4Characteristic curves 5Unit dimensions 6 to 8Valve fixing screws and connections 9Poppet geometry and calculation of minimum pilot pressure 9Maximum flow for various applications 10

Sizes 25 to 80Component series 1XMaximum operating pressure 350 bar

InhaltTable of contents 1Features 1Ordering code 2Symbols 2Function, section 3Technical data (for applications outside these parameters, please consult us!) 4Characteristic curves (measured with HLP46, ϑoil = 40 °C ± 5 °C) 5Unit dimensions: Threaded connection (only size 25) (dimensi-ons in mm) 6Unit dimensions: Threaded connection (only size 32) (dimensi-ons in mm) 7Unit dimensions: Flange connections (size 40 to size 80) (dimensions in mm) 8Valve fixing screws and connections 9Poppet geometry and calculation of the minimum pilot pressure 9Maximum flow qV in l/min (A to B) for various applications 10Notes 11Notes 12

2/10 Bosch Rexroth AG Hydraulics SFA RE 20485/04.08

Ordering code

Symbols

Type SFA… Type SFA…T… (from size 32)

AX

B

P

A B

P T

AX

B

P

T1 T2

A B

P T

Note!Proposed circuit with directional valve and orifice in channel P for a single pre-fill valve. In the case of parallel connection of pre-fill valves, a separate orifice must be provided for each pilot line!

Prefill valve Size 25 = 25 Size 32 = 32 Size 40 = 40 Size 50 = 50 Size 63 = 63 Size 80 = 80Type of connection (port A) for threaded connection (only sizes 25 and 32) = G for flange connection (from size 40) = FWithout tank bore = No codeWith tank bore (from size 32) = TWith pre-decompression (from size 32) = 1 Without pre-decompression = 0

Further details in clear textConnection version

01 = Female pipe thread to ISO 228, DIN 3852 part 2

Seal materialM = NBR seals

(other seals on enquiry) Caution!

Observe compatibility of seals with hydraulic fluid used!

1X = Component series 10 to 19 (Series 10 to 19: unchanged installation and

connection dimensions)

SFA 1X M 01 *

T1/T2

B

3

4

B

A

B

X1

3

2

5

6

P

T1/T2

B

Hydraulics Bosch Rexroth AGRE 20485/04.08 SFA 3/10

Valves of type SFA are pilot operated check valves. They are used for the leak-free isolation of pressurised working circuits (e.g. press cylinders). Due to their good flow characteristics and relatively low closing force of the compression spring (6) on the main poppet, it is ideally suited for the anti-cavitation function and for filling, e.g. main cylinders on presses during fast closing. The integrated pressure port P allows high pres-sure to be built up in the press cylinder! The valves basically consist of housing (1), control spool (2), main poppet (3), pilot poppet (4) and compression springs (5) and (6).A nozzle insert must be provided in channel P of the direc-tional valve. The nozzle diameter must correspond to the size of the prefill valve (see below).Version without pre-decompression The valve allows free flow from A to B. In the opposite di-rection, main poppet (3) is held on its seat by compression spring (6) and the pressure acting in port B. When pressure is applied in pilot port X, control spool (2) is forced down against compression spring (5) and pushes main poppet (3) off its seat. Fluid can now also flow through the valve in the oppo-site direction.Version with pre-decompression The function of this variant largely corresponds to that of the version without pre-decompression.

nozzle insert 1)

Size Nozzle Ø in mm

25 0,832 0,840 0,850 0,863 0,880 1,0

Type SFA..FT1-1X/M/01 (with pre-decompression)

Type SFA..GT0-1X/M/01 (without pre-decompression)

Function, sectionWhen pressure is applied to pilot port X, control spool (2) ini-tially opens pilot poppet (4). This ensures a shock-free de-compression of the compressed hydraulic fluid.

1) Not included in the scope of supply


Technical data (for applications outside these parameters, please consult us!)

GeneralSizes NG 25 32 40 50 63 80Weight kg ca. 4,5 ca. 6 ca. 7 ca. 10,5 ca. 16 ca. 23Installation orientation OptionalAmbient temperature range °C –30 to +80 (NBR seals)

1) Pressure differential across the main poppet to overcome the spring force

2) The cleanliness class stated for the components must be adhered too in hydraulic systems. Effective filtration pre-vents faults from occurring and at the same time increases the component service life.

For the selection of filters see catalogue sheets RE 50070, RE 50076, RE 50081, RE 50086, RE 50087 and RE 50088.

HydraulicMaximum operating pressure

– Port B, P bar 350– Port X bar 150– Port A bar 16

Cracking pressure 1) bar ≈ 0,12Maximum flow l/min See Applications on page 10Hydraulic fluid Mineral oil (HL, HLP) to DIN 51524; other hydraulic fluids on

enquiryHydraulic fluid temperature range °C –30 to +80 (NBR seals)Viscosity range mm2/s 10 to 800Max. permissible degree of contamination of the hydraulic fluid - cleanliness class to ISO 4406 (c)

Class 20/18/15 2)

100 3000 600200

0,3

0,1

0,2

0,42

3

4

500 700400

1

0

0,3

0,1

0,2

0,4

400 800 1200

5 6

200 600 1000100 300 500 700 900 1100


Characteristic curves (measured with HLP46, ϑoil = 40 °C ± 5 °C)

Pressure differential ∆p between ports A and B in relation to flow qV with flow in suction direction from A to B.

Sizes 25, 32, 40 and 50

Pres

sure

diff

eren

tial in

bar

→

Flow in l/min →

Sizes 63 and 80

Pres

sure

diff

eren

tial in

bar

→

Flow in l/min →1 Size 252 Size 323 Size 404 Size 505 Size 636 Size 80

36M14

22

30

0,01/100mm

Rz1max 4

A 6985

G1/4

X

G1

1/4

43,5

67,5110

42,5

39,5 56

15,5

5614

,585

6,5

85

61

Ø25 max

1


1 Nameplate6 4 valve fixing screws

For valve fixing screws, see page 9

Unit dimensions: Threaded connection (only size 25) (dimensions in mm)

3046M16

8 1)

26

8

8 1)

X

A

P

BT1/T2 1)

22

95105

555

1)

T1 1)

T2 1)

17,5

62,552,5

77,8

77,8

105

780,1

1)45

1)

13,6 1) 1,4

1)

5 2 4

6 1

3

0,01/100mm

Rz1max 4

T1/T2 1)G

1/2

76

6G1/4 G1 1/2

3,5

1±0,5

30 max


1 Nameplate2 Seal ring 3 Provide bore Ø6.5 x 6 deep on the mounting face for

valve centring!4 2 off groved dowel pins 6 x 125 Plug screw6 4 valve fixing screws

For valve fixing screws, see page 9

Unit dimensions: Threaded connection (only size 32) (dimensions in mm)

1) Only with version “T“

H12

5 1)

T1 1)

T2 1)

4 x D4

L4L33,5

L2

H8H7

45 1

)

D30,1 1

)

X

A

P

BT1/T2 1)

1

H6

H4H

3

5 2 4

A

3

D1 1)

D2 1) 1,4

1)

D8; H13

L1

H1

H2

T1/T2 1)

D5D6

D7 1)

H10

30

H9

H11

1)

Rz1max 4

0,01/100mm

H5D9 m

ax

7

D10 max

6


Unit dimensions: Flange connections (size 40 to size 80) (dimensions in mm)

Size L1±0,2 L2 L3 L4 ØD1 ØD2 ØD3±0,1 ØD4 ØD5 D6 ØD7 D8 D9 max ØD10 max

40 35.7 88.4±0.2 58 62 10 15.7 90 17.5 58 M16 10 M12 38 4050 42.9 102.5±0.2 70 72 13 19 104 22 71 M20 13 M12 51 5063 50.8 113.15±0.2 80 82 13 19 120 26 90 M24 13 M12 64 6380 61.9 134+0.3 92 95 13 19 140 30 107 M27 13 M16 76 78.5

Size H1 H2±0,2 H3 H4 H5 H6 H7 H8 H9 H10 H11±0,1 H12 H1340 85 69.9 109 102 85 22 116 88.4±0.2 10 26 92 54 1850 101 77.8 132 124 101 22 141 102.5±0.2 12 32 108 66 1863 125 88.9 152 144 125 30 160 113.15±0.2 14 38 130 83 1880 140 106.4 170 158 140 30 185 134+0.3 16 43 150 90 21

1 Nameplate2 Seal ring 3 Provide bore Ø6.5 x 6 deep on the mounting face for

valve centring!4 2 off grooved dowel pins 6 x 125 Valve fixing screw (only with version “T“)6 4 valve fixing screws7 Flange connection to ISO 6162-1

For valve fixing screws and connections, see page 9

1) only with version “T“

B

A

A2

A1

A3

X

F2F1

H1H2

pö 0,12 bar

VSt


Valve fixing screws and connectionsValve fixing screws (separate order)For reasons of strenght, use exclusively the following valve fixing screws:

4 socket head cap screws to ISO 4762 - 10.9 or DIN 912 - 10.9 Friction coefficient µtotal = 0.09 to 0.14

Poppet geometry and calculation of the minimum pilot pressure

Without pre-decompression With pre-decompression

Size A1 in cm2

A2 1) in cm2

A3 in cm2

H1 in mm

H2 in mm

F1 in N

F2 in N

Vst in cm3

Unlocking ratio2) in bar 3) in bar

25 5.31 – 1.33 6.2 5 6 bis 14 38 bis 70 0.66 4.0 –32 8.04 0.5 2.01 8.5 6.5 9 bis 22 58 bis 109 1.30 4.0 0.340 13.52 0.78 3.14 10 7 14 bis 29 93 bis 162 2.20 4.3 0.350 21.24 1.13 4.71 12.5 9 23 bis 49 149 bis 261 4.20 4.5 0.363 32.67 1.77 7.07 14.5 11 35 bis 63 206 bis 348 7.80 4.6 0.380 49.02 2.54 10.18 17 13 57 bis 127 310 bis 579 13.20 4.8 0.3

1) Not provided with version „without pre-decompession“ (SFA...0...)

2) Without pre-decompression3) With pre-decompression

A1 = Effective area of main poppetA2 = Effective area of pilot poppetA3 = Effective area of control spoolH1 = Main poppet strokeH2 = Control spool strokeF1 = Spring force of valve springF2 = Spring force of control spool compression springVst = Pilot flow for opening the valvepÖ = Cracking pressure (pressure differential across the

main poppet for overcoming spring force F1)pSt = Pilot pressure in port XpB = System pressure in port B

Unlocking ratio = Pilot pressure pSt

System pressure pB

Example: Type SFA32…G0; pB = 30 barpSt = 4.0 x 30 bar = 120 bar

Valve fixing screws ConnectionsSize Dimensions Tightening torque MT in Nm (±4 %)

A P XSocket head cap screws

ISO 4762 - 10.9Socket head cap screws

DIN 912 - 10.925 M14 x 90 170 – G1 1/4 – G1/432 M16 x 100 280 – G1 1/2 G1/2 G1/440 M16 x 110 280 – DN38 1) G1/2 G1/450 M20 x 130 560 – DN51 1) G1/2 G1/463 M24 x 160 960 – DN64 1) G3/4 G1/480 M27 x 180 – 1400 DN76 1) G3/4 G1/2

1) to ISO 6162-1


Bosch Rexroth AG HydraulicsZum Eisengießer 197816 Lohr am Main, Germany Phone +49 (0) 93 52 / 18-0 Fax +49 (0) 93 52 / 18-23 [email protected] www.boschrexroth.de

© This document, as well as the data, specifications and other informati-on set forth in it, are the exclusive property of Bosch Rexroth AG. It may not be reproduced or given to third parties without its consent.The data specified above only serve to describe the product. No statements concerning a certain condition or suitability for a certain application can be derived from our information. The information given does not release the user from the obligation of own judgment and verification. It must be remembered that our products are subject to a natural process of wear and aging.

Maximum flow qV in l/min (A to B) for various applications

Size 25 32 40 50 63 80Application 1 125 200 300 500 800 1200Application 2 90 170 250 400 650 1000Application 3 60 140 220 360 560 900Application 4 40 100 150 240 380 620Application 5 20 70 110 170 280 450

Applications

Important!If the prefill valve or the selected pipe are too small, gases may be released from the hydraulic fluid with the related consequences, which can often lead to damage to cylinder seals in the long run.

Application 1 Application 2 Application 3

a

4

321

AB

a

b

2

1

A

Bc a

b

2

1 B

A

Capacity of the filling tank min. 1.5 x cylinder volume

Application 4 Application 5 Notes on applications 2 to 5

a

b

2

1

A

B

a

b

2

1A

B h

A

B

In the case of operating parameters close to limit values, please consult us. It is, however, often sufficient to select

the next larger size of pipes.

1 Cylinder2 Prefill valve3 This metal sheet is not included in the scope of supply.

It prevents the formation of suction vortexes in the case of small tank sizes or at minimum hydraulic fluid level (a).

4 Take note of the supply cross-section - differs depend-ing on size!

a Min. 300 mm with extended cylinderb Up to 1000 mm with the specified maximum flowsc ≥ 500 mmh ~300 mm to max. 500 mm




Notes

preenchimento sfa - re20485

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