Walle produce all series of hydraulic seals,according to category by purpose,including rotary seals, all kinds of O ring(FKM O ring), step seal, glyd ring, oil seal and various of combination seals, gasket, spring energised seals, food machinery seals and so on.

1. © Merkel Freudenberg Fluidtechnic GmbH | Seals for Fluid Power Catalog 2007
Hydraulics | Rod Seals | Merkel U-Ring T 23
Merkel U-Ring T 23
PUR profile ring
POM back-up ring
Asymmetrical sealing lip
Fig. 1 Merkel U-ring T23
Product description
Two-piece Merkel seal set with shortened
inner lip and active back-up ring with
press fit at the outside diameter.
Product advantages
The Merkel U-Ring T 23 is mainly used
with high pressures and is designed for
housings according to ISO 5597
Bridges large gaps even with high
pressures
Wide operating temperature range
Very good static and dynamic
tightness
High resistance to wear.
Application
Earth moving equipment, steel hydraulics
engineering, heavy-duty mobile hydrau-
lics, marine hydraulics, support cylinders,
scrap cutters.
Material
Material Code Hardness
Polyurethane 95 AU V142 95 Shore A
Material Code
Polyacetal POM PO202
Operating conditions
Material 95 AU V142/POM PO202
Temperature range in °C
Hydraulic oils HL, HLP –30 … +110
HFA fluids +5 … +50
HFB fluids +5 … +50
HFC fluids –30 … +40
HFD fluids –
Water +5 … +50
HETG (rapeseed oil) –30 … +60
HEES (synthetic ester) –30 … +80
HEPG (glycol) –30 … +50
Mineral greases –30 … +110
Pressure p in MPa 50
Running speed v in m/s 0,1
Surface quality
Surface roughness Ra Rmax
Sliding surface 0,05 … 0,3 µm ≤2,5 µm
Groove base ≤1,6 µm ≤6,3 µm
Groove flanks ≤3,0 µm ≤15,0 µm
Percentage contact area Mr >50% to max. 90% at cutting depth c = Rz/2 and reference line C ref = 0%.
Merkel U-Ring T 23

2. © Merkel Freudenberg Fluidtechnic GmbH | Seals for Fluid Power Catalog 2007
Design notes
Please observe our general design notes in → Technical Manual.
Gap dimension
The decisive factor for the function of the seal is the largest gap dimension occurring
during operation on the non-pressurised side of the seal. → Technical Manual.
Tolerance recommendation and dimension D2
The admissible gap width, tolerances, guide play and deflection of the guide under
load are to be taken into account when designing D2. → Technical Manual.
Dimensions D1 and DF must be considered in connection with the guide element used.
16 MPa 26 MPa 32 MPa 40 MPa
Nominal
Ø D
Profile D d X2 D d X2 D d X2 D d X2
… 180
7,5 … 8,5
(BR 3,5)
H10 f8 0,8 H10 f8 0,7 H10 f8 0,50 H10 f8 0,4
>180 … 310
7,5 … 15,0
(BR 5,0)
H10 f8 1,2 H10 f8 1,0 H10 f8 0,65 H10 f8 0,5
>310 … 400
12,5 … 15,0
(BR 7,5)
H10 f8 1,8 H10 f8 1,4 H10 f8 0,90 H10 f8 0,7
Fitting & installation
Careful fitting is a prerequisite for the correct function of the seal. → Technical
Manual. Dimensions listed in the table of dimensions with "h" can be fitted by hand
into plunge-cut grooves. Articles identified with "w" can be easily fitted into plunge-cut
grooves with a fitting tool. We will be pleased to supply a design drawing for this on
enquiry.
Hydraulics | Rod Seals | Merkel U-Ring T 23

3. © Merkel Freudenberg Fluidtechnic GmbH | Seals for Fluid Power Catalog 2007
Hydraulics | Rod Seals | Merkel U-Ring T 23
Article list
DFØdØDØ
C
H
D2Ø D1Ø
L+0,2
R
1
0,4
30°
Rounded and free of burrs
Rounded and free of burrs R
2
<0,2
d D H L Profile C Fitting Housing Material Article No.
40 55 11,4 12,5 7,5 6 W ISO 95 AU V142 24302155 DD
50 65 11,4 12,5 7,5 6 W ISO 95 AU V142 24302156 DD
60 75 11,4 12,5 7,5 6 W 95 AU V142 24302157 BB
70 85 11,4 12,5 7,5 6 W ISO 95 AU V142 24295613 BB
80 95 11,4 12,5 7,5 6 W ISO 95 AU V142 24302158 BB
80 100 14,6 16 10 7 W ISO 95 AU V142 24332093 BB
90 110 14,6 16 10 7 W ISO 95 AU V142 24265875 BB
100 115 14,6 16 7,5 6 W 95 AU V142 24377482 DD
100 120 14,6 16 10 7 W ISO 95 AU V142 24302127 BB
110 125 14,6 16 7,5 6 W 95 AU V142 24377483 DD
110 130 14,6 16 10 7 W ISO 95 AU V142 24265876 BB
120 135 14,6 16 7,5 6 W 95 AU V142 24344467 DD
125 140 11,4 12,5 7,5 6 H 95 AU V142 24332131 DD
125 145 14,6 16 10 7 H ISO 95 AU V142 24302159 BB
140 160 14,6 16 10 7 H ISO 95 AU V142 24302160 BB
170 185 14,6 16 7,5 6 H 95 AU V142 24306416 BB
170 190 14,6 16 10 7 H 95 AU V142 24377490 DD
180 195 11,4 12,5 7,5 6 H 95 AU V142 24377491 DD
180 200 19,1 21 10 7 H 95 AU V142 24332132 BB
BB Available from stockAvailable from stock DD On request: Tool is available, delivery at short noticeOn request: Tool is available, delivery at short notice
Fitting: H = by hand; W = with fitting tool; blank = axially accessible housingFitting: H = by hand; W = with fitting tool; blank = axially accessible housing

4. © Merkel Freudenberg Fluidtechnic GmbH | Seals for Fluid Power Catalog 2007
Merkel Freudenberg
Fluidtechnic GmbH
Industriestr. 64
D-21107 Hamburg
Tel.: +49(0)40/75 30 6-0
Fax: +49(0)40/75 30 6-440
E-mail: merkel@freudenberg.de
www.merkel-freudenberg.de
The catalog details are based on the
experience of many years of research
in the development and production of
seals in the Freudenberg Group and
correspond to our current level of know-
how.
The sealing action of many catalog
products is, however, not only created
by the component itself. In many
cases – depending on the specific
application – it depends significantly on
the other parameters, such as installa-
tion point, counter surface, pressure,
operating temperature, media to be
sealed, lubrication, effects of vibration
and any ingress of dirt from outside.
These and other unknown factors in
practical use may noticeably influence
the functioning of the seals. Against this
background generalised statements
on the function of the catalog products
are not possible. Details in this catalog
merely represent general and non-bin-
ding reference values which make no
claim to be valid for every application.
We therefore recommend you to always
discuss specific applications with our
consultancy service. In the event of very
high and special loads, for example due
to aggressive media, the seal should be
selected in co-operation with us; trials to
check the functional reliability are often
indispensable.