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 Seal Set 0214
Merkel U-Ring Seal Set 0214
NBR U-ring
Back-up ring
Fabric
Fig. 1 Merkel U-Ring Seal Set 0214
Product description
Two-piece Merkel seal set comprising
an elastomer U-ring with an elastomer
sealing edge, fabric reinforcement on the
contact area and an active back-up ring.
Product advantages
Single-acting rod seal for use in hydrau-
lics and pneumatics
Low friction due to fabric
reinforcement
Large range of dimensions
Protection against extrusion through
activated back-up ring
Low deformation value
(not suitable for sealing systems)
Easily installed in non-axial housings
From 100 mm diameter.
Application
Injection moulding machines, iron and
steel technology, presses, special cylin-
ders, marine hydraulics, steel hydraulics
engineering, scrap cutters.
Material
U-Ring
Material Code
NBR 80 NBR B246
Cotton fabric BI-NBR B4 B248
Back-up ring
D Material Code
<300 mm Polyacetal POM POM PO202
>300 mm Polyamide PA 6.G200
Other materials like PTFE bronze back-up ring on enquiry.
Operating conditions
Material
80 NBR B246/BI-NBR B4B248/
POM PO202
80 NBR B246/BI-NBR B4B248/
PA 6.G200
Temperature range in °C
Hydraulic oils HL, HLP –30 … +100 –30 … +100
HFA fluids +5 … +60 +5 … +60
HFB fluids +5 … +60 +5 … +60
HFC fluids –30 … +60 –30 … +60
HFD fluids – –
Water +5 … +100 +5 … +100
HETG (rapeseed oil) –30 … +80 –30 … +80
HEES (synthetic ester) –30 … +80 –30 … +80
HEPG (glycol) –30 … +60 –30 … +60
Mineral greases –30 … +100 –30 … +100
Pressure p in MPa Hydraulic 25 or 40*
Pressure p in MPa Pneumatic 5
Running speed v in m/s 1,5
* max. pressure depends on the profile.
For Merkel U-Ring Seal Sets 0214, if long strokes are traversed, the max. pressure
should only be applied to the last part of the stroke (closing pressure); during the
stroke max. 16 MPa.
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 Seal Set 0214

2. © Merkel Freudenberg Fluidtechnic GmbH | Seals for Fluid Power Catalog 2007
Hydraulics | Rod Seals | Merkel U-Ring Seal Set 0214
Design notes
Please observe our general design notes in → Technical Manual.
Gap dimension X2
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.
Profile 16 MPa 26 MPa 32 MPa 40 MPa
D d X2 D d X2 D d X2 D d X2
<15 H10 f7 1,2 H10 f7 1,0 H10 f7 0,65 H10 f7 0,5
>15 H10 f7 1,8 H10 f7 1,4 H10 f7 0,9 H10 f7 0,7
The dimensions D1 and DF are to be viewed in connection with the sealing component used.
Tolerance recommendation
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.
Fitting & installation
Careful fitting is a prerequisite for the correct function of the seal.
→ Technical Manual.

3. © Merkel Freudenberg Fluidtechnic GmbH | Seals for Fluid Power Catalog 2007
Hydraulics | Rod Seals | Merkel U-Ring Seal Set 0214
Article list
H
h
R1 0,4
L
+0,2
<0,2
C
ØD
Ød2
Ød1
Ød
20°
rounded and burr-freerounded and burr-free
d D H L Profile C Material Article No.
140 170 18 19 15 7,5 80 NBR B246 24314112 DD
150 180 18 19 15 7,5 80 NBR B246 24296304 DD
170 195 18,5 20 12,5 6,5 80 NBR B246 24299328 DD
170 200 22 23 15 7,5 80 NBR B246 24294436 DD
180 210 18 19 15 7,5 80 NBR B246 24245484 DD
180 210 22 23 15 7,5 80 NBR B246 24315582 DD
190 220 22 23 15 7,5 80 NBR B246 24262669 DD
210 240 22 23 15 7,5 80 NBR B246 24251000 DD
220 250 19 20 15 7,5 80 NBR B246 24245485 DD
240 270 22 23 15 7,5 80 NBR B246 24243972 DD
250 280 22 23 15 7,5 80 NBR B246 24265061 DD
270 300 22 23 15 7,5 80 NBR B246 24266413 DD
280 310 22 23 15 7,5 80 NBR B246 24265062 DD
300 330 22 23 15 7,5 80 NBR B246 24237123 DD
300 340 24 25 20 10 80 NBR B246 24245487 DD
320 360 20 21 20 10 80 NBR B246 24245104 DD
320 360 30 32 20 10 80 NBR B246 24262827 DD
350 380 25 26 15 7,5 80 NBR B246 24248695 DD
350 390 30 32 20 10 80 NBR B246 49000836 DD
370 400 25 26 15 7,5 80 NBR B246 24310654 DD
380 420 30 32 20 10 80 NBR B246 24265065 DD
390 420 25 26,5 15 7,5 80 NBR B246 24289371 DD
420 450 25 26,5 15 7,5 80 NBR B246 24299742 DD
450 490 30 32 20 10 80 NBR B246 24227265 DD
480 520 30 32 20 10 80 NBR B246 24245108 DD
500 540 30 32 20 10 80 NBR B246 24245110 DD
530 560 25 26,5 15 7,5 80 NBR B246 24293085 DD
560 600 25 26 20 10 80 NBR B246 24287009 DD
580 620 30 32 20 10 80 NBR B246 24245106 DD
800 850 32 34 25 12,5 80 NBR B246 24300506 DD
850 890 30 32 20 10 80 NBR B246 24311337 DD
1000 1050 37,5 40 25 12,5 80 NBR B246 24293084 DD
BB Available from stockAvailable from stock DD On request: Tool is available, delivery at short noticeOn request: Tool is available, delivery at short notice

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.