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BECA 391

BECA 391
beca_391_3d_v1
beca_391_3d_v2

Description

The BECA 391 profile is a rubber pneumatic cushioning seal.

Advantages

Effective and consistent damping effect with automatic centring

Technical data

Temperature

-30°C/+150°C

Pressure

1.6 MPa

Speed

1 m/s

Medias

Lubricated air
Oil-free air
Non-aggressive gases

Applications

Shock absorbers
Distributor
Standard cylinders

Materials

NBR 90 Shore A
FKM 90 Shore A

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Dimensions
Materials
Technical data

Dimensions

Installation drawingLogement Gorge Joint d'amortissement pneumatique - Housing Groove Pneumatic shock absorber seal - BECA 391

Materials

NBR

Nitrile rubber (NBR) is the general term for acrylonitrile-butadiene copolymer. The ACN content can vary between 18% and 50%. While the acrylonitrile content is important, the resistance to oil and fuel is more so. Conversely, the elasticity and compression set are not as good. The NBR has good mechanical properties and good wear resistance. However, its resistance to atmospheric agents and the ozone is relatively low.

Chemical resistance Aliphatic hydrocarbons (propane, butane, petroleum, diesel fuel)
Mineral oils and greases
Fire-resistant fluids (HFA, HFB and HFC)
Diluted acids, low-temperature alkaline and saline solutions
Water (up to +100°C max)
Compatibility issue Fuels with high aromatic content
Aromatic hydrocarbons (benzene)
Chlorinated hydrocarbons (trichlorethylene)
Polar solvents (ketone, acetone, acetic acid, ethylene-ester)
Strong acids
Glycol-based brake fluids
Atmospheric and ozone agents
Temperature range -30°C/+100°C

FKM

Depending on their structure and fluorine content, the chemical resistance and resistance to the cold in fluororubbers can vary. This FKM-based rubber is very often used for high-temperature hydraulics and pneumatics, for industrial valves, injection/fuel systems, motor seals and high-vacuum systems.

Chemical resistance Mineral oils and greases, ASTM n°1, IRM 902 and IRM 903 oils.
Fire-resistant liquids (HFD)
Silicone oils and greases
Mineral and vegetable oils and greases
Aliphatic hydrocarbons (propane, butane, petroleum)
Aromatic hydrocarbons (benzene, toluene)
Chlorinated hydrocarbons (trichlorethylene)
Fuel (including high alcohol content)
Atmospheric and ozone agents
Compatibility issue Glycol-based brake fluids
Ammonia gas
Organic acids with a low molecular weight (formic and acetic acids)
Temperature range -20°C/+200°C

Technical data

Housing Groove Pneumatic Shock Absorber Seal - BECA 391

Surface roughness

Roughness Dynamic surface area Static surface area Groove flanks
Ra 0.1 - 0.4 µm ≤ 1.6 µm ≤ 3.2 µm
Rz 0.63 - 2.5 µm ≤ 6.3 µm ≤ 10.0 µm
Rmax 1.0 - 4.0 µm ≤ 10.0 µm ≤ 16.0 µm

Only on request