Lens gaskets0 pages
Lens gaskets
The proven high-pressure gaskets
Lens gaskets are reusable, as the sealing effect is generally achieved by elastic deformation of the surfaces.
We can also specially produce bellows lenses, lens blind
spectacle gaskets and half-lenses.
The projected sealing width bG is calculated in relation to the
angle a, which forms the sealing surface against the direction of the force (tubular axis) depending on the E modulus
EG and the surface pressure exerted by bG = 100 · σ / EG · r ·
sinα.
Lens blind spectacle gaskets are made of a sealing lens
and a lens blind, which are connected by a ligament. It is
also usual to use lens blinds on their own. In this case, it is
useful to weld on a small plate to render the lens blind distinguishable.
Gasket profiles
Profile
Profile A5BS
Specify DN, PN, size
a and d when ordering
Cross-section
06
A5
A5S
A5BS
Steel type
designation
Lens gaskets are impervious to overpressure. With increasing loads, the contact surface between the spherical lens
surface and the spherical flange groove increases, so that
the surface pressure only increases to a lesser extent.
A disadvantage with standard sealing lenses is that, at high
pressures and temperatures, the sealing lens can bulge
along the circumference and weaken the tension of the connection. Also, at greater nominal diameter, the flange can
become stuck in the area of the raised face diameter d5 and
lift up at the sealing diameter.
Material
number
For circulatory
temperatures
Code designation
on the outer edge
S235JRG2
P265GH
16Mo3
13CrMo4-5
10CrMo9-10
X6CrNiTi18-10
12CrMo19-5
1.0038
1.0425
1.5415
1.7335
1.7380
1.4541
1.7362
to 425 0C
to 425 0C
425 to 475
425 to 520
520 to 580
350 to 550
max. 650 0C
none
none
1 Punch mark
2 Punch marks
3 Punch marks
4 Punch marks
1 notch
X6CrNiMoTi17-12-2
1.4571
max. 550 0C 3 notches
Further technical data see section “Materials commonly used”.
Recommended max. roughness
of the flange surfaces
µm
Surface pressure
limits for 20 °C
N/mm2
N/mm2
E modulus at 20 °C
Surface pressure
limits for 300 °C
N/mm
N/mm2
E modulus at 300 °C
kN/mm2
Monel 2.4360
Steel 1.4541
silver-plated
Steel St 35
copper-plated
Stainless steel
1.4828
Stainless steel
1.4541
von
bis
3,2
6,3
3,2
6,3
3,2
6,3
1,6
3,2
1,6
3,2
3,2
6,3
6,3
12,5
3,2
6,3
3,2
6,3
σv
σϑ
235
525
300
675
400
900
335
750
400
900
135
600
100
750
135
300
260
660
210
210
210
200
200
210
200
128
178
235
315
300
585
400
730
335
630
400
750
135
390
100
630
135
150
260
650
185
185
190
186
186
185
186
114
175
kN/mm2
2
Heatresistant mild
steel 1.7362
Materials
Heat-resistant
mild steel
1.5415
A5, A5S, A5BS
Iron 1.1003
Profile
Copper 2.0090
Gasket limiting values
σv
σϑ
Kempchen Dichtungstechnik GmbH · Tel. +49 (0)208 8482 0 · Fax. +49 (0)208 8482 285 · info@kempchen.de · www.kempchen.de
Lens gaskets
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