Prefill valve, actively operatable RE 20473/12.

06
Replaces: 06.06
/6

Type SFS

Sizes 200 to 300

Component series 4X
Maximum operating pressure 350 bar

SFS200

Table of contents Features

Contents Page – Hydraulically, actively switchable prefill valve (check valve) for
Features 1 flanged connection
Ordering code 2 – Reduced switching noise due to end position cushioning ef-
fective on both sides
Poppet geometry and determination
of minimum pilot pressure 2 – Optimised switching time characteristics
Function, section, symbol 3
Technical data 4
Maximum switching times 4
Unit dimensions 5
Maximum flow
for various applications 6

Information on available spare parts:

www.boschrexroth.com/spc
/6 Bosch Rexroth AG Hydraulics SFS RE 20473/12.06

Ordering code

SFS A 0 1 4X *

Prefill valve Further details in clear text

Size 200 = 200 Seal material
Size 250 = 250 No code = NBR seals
Size 300 = 300 Caution!
Type of connection Observe compatibility of seals
Flanged connection =A with hydraulic fluid used!

Without pre-compression feature =0 4X = Component series 40 to 49

(40 to 49: unchanged installation and
connection dimensions)
1 = Main piston can be actively controlled

Poppet geometry and determination of minimum pilot pressure

A1 = Effective area of main poppet

A3
A2 = Effective area of pilot piston for “closing“
X1 X A3 = Effective area of pilot piston for “opening“
s= Piston stroke
V1 = Pilot oil flow for opening the valve
s

V2 = Pilot oil flow for closing the valve

A2 pSt = Pilot pressure in port X
pB = Operating pressure in port B

Pilot pressure pp
Unchecking ratio =
B System pressure pB
A1

Size A1 A2 A3 s V1 V2 Unchecking ratio

in cm2 in cm2 in cm2 in mm in cm3 in cm3 in bar
200 216.4 36.4 50.3 42.0 211.0 153.0 4.3
250 373.2 67.4 95.0 52.5 503.7 353.8 3.9
300 572.6 92.86 143.1 63.0 901.8 585.0 4.0

Example (type SFS 200 A0…):

pB = 30 bar; pp = 4.3 x 30 bar = 129 bar
RE 20473/12.06 SFS Hydraulics Bosch Rexroth AG /6

Function, section, symbol

Valves of type SFS are hydraulically, actively operatable prefill The valves allow free flow from A to B while pilot port X1 is de-
valves (check valves). They are used for the leak-free isolation pressurised. In the opposite direction, poppet (2) is held on its
of pressurised working circuits, mainly in press cylinders. The seat by the pressure acting in port B. Due to pressure present
possibility of actively influencing the opening and closing proc- in pilot port X, poppet (2) is pushed off its seat. This allows a
ess results in a reduction in switching times when compared free flow through the valve also in the opposite direction. Clos-
with a conventional prefill valve. ing of the piston can be initiated via pilot port X1.
The valves basically consist of housing (1), poppet (2), connec- The opening and closing time can be influenced by means of
tion cover (3), pilot piston (4), mounting flange (5) and guide the pilot oil flow (throttling).
(6). For technical data for the calculation of the required pilot pres-
sure, see page 2.

Pilot port X: “opening“

Pilot port X1: “closing“

X1 X

A 1

6
Symbol

B X1

B B
A X

B
/6 Bosch Rexroth AG Hydraulics SFS RE 20473/12.06

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

General
Size 200 250 300

Weight kg 190 380 655

Installation orientation Optional

Port A DN 200 250 300
(flange to EN 1092-1/11…/ PN16)
Port X1 G1 G1 1/4 G1 1/4

Port X G1 1/4 G1 1/2 G1 1/2

Hydraulic
Maximum operating pres- – Port A bar 16
sure
– Port B bar 350

– Ports X and X1 bar 150

Hydraulic fluid Mineral oil (HL, HLP) to DIN 51524; fast bio-degradable hy-
draulic fluids according to VDMA 24568 (see also RE 90221);
HETG (rape seed oil); other hydraulic fluids on enquiry
Hydraulic fluid temperature range °C –30 to +80
Viscosity range mm2/s 10 to 800
Max. permissible degree of contamination of the Class 20/18/15 1)
hydraulic fluid - cleanliness class to ISO 4406 (c)

1) The
cleanliness classes specified for components must be For the selection of filters, see data sheets RE 50070,
adhered to in hydraulic systems. Effective filtration prevents RE 50076, RE 50081, RE 50086, RE 50087 and
malfunction and, at the same time, increases the service life RE 50088.
of components.

Maximum switching times

Maximum switching time in ms

Size (at X, X1 = 150 bar)
Closing Opening
200 60 70
250 70 80
300 110 90
The switching time depends on the line resistance, pilot valve
and pilot oil flow.
RE 20473/12.06 SFS Hydraulics Bosch Rexroth AG /6

Unit dimensions (nominal dimensions in mm)

B1
ØD1
D9 B4 D8 N1; 12 x ØD6
B2
B3 X1 X
1
ØD2
1
5
ØD
A
ØD4
ØD3

H1
H3
2
3 H5
H4

N2 1 Housing can be mounted steplessly rotat-

ØD7
H2

ed through 360°

B 2 Flange to EN 1092-1/11…/PN16
3 Nameplate
ØD10 T2 Depth of fit
ØD11 N2 Number of valve fixing screws arranged
at equally spaced intervalls on the bolt cir-
cle (separate order)
The following valve fixing screws are rec-
ommended:
ØD13±0,2
Hexagon socket head cap screws
ØD12H7
ISO 21269 - 10.9
0,01 ØD15 min Friction coefficent µtotal = 0.12 to 0.17
0,01

D14
Rz16

Size Dimensions Tightening

Rz63

N2
Rz8

20 in mm torque MT in
R1
T3

Nm
200 M36 x 3 x 150 3100
T2
T1

250 M42 x 3 x 180 5100

T4 min

300 M42 x 3 x 220 5100

Size B1 B2 B3 B4 ØD1 ØD2 ØD3 ØD4 ØD5 ØD6 ØD7 D8 D9 ØD10

200 275 24 3 60 168 273 268 340 295 22 40 G1 1/4 G1 350
250 330 26 3 80 225 356 320 405 355 26 46 G1 1/2 G1 1/4 445
300 380 28 4 94 250 419 378 460 410 26 46 G1 1/2 G1 1/4 525
Size ØD11 ØD12 ØD13 ØD14 D15 H1 H2 H3 H4 H5 N1 N2 T1 T2 T3 T4 R1
200 420 290 350 M36 x 3 270 445 180 255 35 100 12 15 37 26 5 50 3
250 530 380 445 M42 x 3 355 571 240 320 55 120 12 18 57 42 8 60 5
300 610 450 525 M42 x 3 425 684 305 390 55 160 12 24 57 42 8 75 5
/6 Bosch Rexroth AG Hydraulics SFS RE 20473/12.06

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

Size 200 250 300 Caution!

Application 1 5600 10000 14000 Too small a prefill valve or an insufficiently dimensioned pipe
results in gas escaping from the hydraulic fluid with the asso-
Application 2 4340 6775 9750
ciated consequences and frequently to long-term damage to
Application 3 3770 5890 8480 cylinder seals.
Application 4 1510 2360 3400

Applications

Application 1 Application 2
b
a

a
c

b
2 1
1
Size of the prefill tank
min. 1.5 x cylinder volume

Application 3 Application 4
b b 1 Cylinder

2 2 2 Prefill valve
a Min. 300 mm with extended cyl-
a

1 1
h

inder
b Up to 1000 mm with specified
a

maximum flows
c ≤ 500 mm
h 300 mm ≤ h < 500 mm
Note on applications 1 to 4

For applications close to the limiting pa-

rameters, please consult us. It is, howev-
er, often sufficient to select the pipe one
size larger.

Bosch Rexroth AG © This document, as well as the data, specifications and other information
Hydraulics set forth in it, are the exclusive property of Bosch Rexroth AG. Without
Zum Eisengießer 1 their consent it may not be reproduced or given to third parties.
97816 Lohr am Main, Germany The data specified above only serve to describe the product. No state-
Phone +49 (0) 93 52 / 18-0 ments concerning a certain condition or suitability for a certain application
Fax +49 (0) 93 52 / 18-23 58 can be derived from our information. The information given does not release
documentation@boschrexroth.de the user from the obligation of own judgment and verification. It must be
www.boschrexroth.de remembered that our products are subject to a natural process of wear and
aging.
RE 20473/12.06 SFS Hydraulics Bosch Rexroth AG /6

Notes

Bosch Rexroth AG © This document, as well as the data, specifications and other information
Hydraulics set forth in it, are the exclusive property of Bosch Rexroth AG. Without
Zum Eisengießer 1 their consent it may not be reproduced or given to third parties.
97816 Lohr am Main, Germany The data specified above only serve to describe the product. No state-
Phone +49 (0) 93 52 / 18-0 ments concerning a certain condition or suitability for a certain application
Fax +49 (0) 93 52 / 18-23 58 can be derived from our information. The information given does not release
documentation@boschrexroth.de the user from the obligation of own judgment and verification. It must be
www.boschrexroth.de remembered that our products are subject to a natural process of wear and
aging.
/6 Bosch Rexroth AG Hydraulics SFS RE 20473/12.06

Notes

Bosch Rexroth AG © This document, as well as the data, specifications and other information
Hydraulics set forth in it, are the exclusive property of Bosch Rexroth AG. Without
Zum Eisengießer 1 their consent it may not be reproduced or given to third parties.
97816 Lohr am Main, Germany The data specified above only serve to describe the product. No state-
Phone +49 (0) 93 52 / 18-0 ments concerning a certain condition or suitability for a certain application
Fax +49 (0) 93 52 / 18-23 58 can be derived from our information. The information given does not release
documentation@boschrexroth.de the user from the obligation of own judgment and verification. It must be
www.boschrexroth.de remembered that our products are subject to a natural process of wear and
aging.