KA6
Description
The KA6 profile is a type 6-flanged shaft seal composed of a single external metal cage, a metal reinforcement, a metal flange, a primary sealing lip without a spring and an additional anti-pollution sealing lip.
Advantages
Excellent radial rigidity, particularly for large diameters
Very good stability when assembled, preventing the bounce-back effect
Precise assembly in the housing with a flange
Sealing for high viscosity fluids
Primary sealing lip generating low levels of friction and heat
Protection against undesirable air contaminants
Technical data
Applications
All types of rotative applications
Machine tools
Agriculture
Construction
Transmissions
Gear boxes
Motors
Pumps
Materials
Rubber
ACM 70 - 75 Shore A
EPDM 70 - 75 Shore A
FKM 70 - 75 Shore A
HNBR 70 - 75 Shore A
NBR 70 - 75 Shore A
Metal cage
Steel - AISI 1010
Stainless steel - AISI 304
Stainless steel - AISI 316
for use
Dimensions
Materials
Metal cage
The table below shows the materials that we can offer for metal cages.
Application | Material | Standard | Characteristics |
---|---|---|---|
Metal cage | Non-alloy standard steel | AISI 1010 (DIN 1624) |
Cold rolled steel |
Metal cage | Nickel chrome steel | AISI 304 (DIN 1.4301 - V2A) |
Standard stainless steel |
Metal cage | Chrome-nickel-molybdenum steel | AISI 316 (DIN 1.4401 - V4A) |
Stainless steel highly resistant to corrosion |
Rubbers
ACM (Polyacrylate)
Polymers containing ethyl acrylate (or butyl acrylate) have a small amount of monomer, which is necessary for cross-linking; ACM is a material with better heat resistance than NBR. It is often used for automatic gearboxes.
Chemical resistance | Mineral oils (motor oils, gear box oils, ATF oils) Atmospheric and ozone agents |
---|---|
Compatibility issue | Glycol-based brake fluids (Dot 3 & 4) Aromatic and chlorinated hydrocarbons Water and steam Acids, alkalis and amines |
Temperature range | -25°C to + 150°C (short-term peak at +160°C) -35°C / +150°C with particular ACMs |
AEM (ethylene acrylate rubber)
As a methyl acrylate and ethylene copolymer, AEM is considered to be more resistant to heat than ACM. Its characteristics make it an intermediary between ACM and FKM.
Chemical resistance | Cooling fluids Aggressive mineral oils Atmospheric agents Water |
---|---|
Compatibility issue | Aromatic solvents Strong acids Brake fluids Gearbox oils ATF oils |
Temperature range | - 40°C to + 150°C |
CR (Polychloroprene)
This CR-based rubber is used in the refrigeration industry and for ventilation systems. This chloroprene was the first synthetic rubber to be developed and marketed.
Chemical resistance | Paraffinic mineral oils Silicone oils and greases Water and water-based solvents for use at low temperatures Refrigerant fluids Ammoniac Carbon dioxide Atmospheric and ozone agents |
---|---|
Limited chemical resistance | Naphthenic mineral oils Aliphatic hydrocarbons (propane, butane, petroleum) Glycol-based brake fluids |
Compatibility issue | Aromatic hydrocarbons (benzene) Chlorinated hydrocarbons (trichlorethylene) Polar solvents (ketone, acetone, acetic acid, ethylene-ester) |
Temperature range | -40°C / +100°C (short-term peak at +120°C) |
EPDM (Ethylene Propylene Diene Monomer rubber)
As an Ethylene Propylene Diene Monomer copolymer, EPDM is commonly used for hot water taps, cooling systems, brake systems, dishwashers and washing machines.
Chemical resistance | Hot water and steam up to +150°C Glycol-based brake fluids (Dot 3 & 4) and silicone-based brake fluids (Dot 5) Organic and inorganic acids Cleaning agents, sodium and potassium alkalis Hydraulic fluids (HFD-R) Silicone oils and greases Polar solvents (alcohols, ketones and esters) Atmospheric and ozone agents |
---|---|
Compatibility issue | Mineral oils and greases Hydrocarbons Low impermeability to gas |
Temperature range | -45°C / +150°C (short-term peak at +175°C) |
FFKM (perfluorinated rubber)
FFKM has the best characteristics for resistance to high temperatures, with an excellent chemical inertia. This FKM-based rubber is very often used for high-temperature hydraulic and pneumatic systems, industrial valves, injection/fuel systems, motor seals and high-vacuum systems.
Chemical resistance | Aliphatic and aromatic hydrocarbons Polar solvents (ketones, esters and ethers) Organic and inorganic acids Water and steam High-vacuum system |
---|---|
Compatibility issue | Coolants (R11, R12, R13, R113, R114, etc.) PFPE |
Temperature range | -15°C/+320°C |
FKM (fluorinated rubber)
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 (short-term peak at +230°C) -40°C / +200°C with particular FKMs |
FVMQ (fluorosilicone rubber)
The FVMQ has mechanical and physical properties that are very similar to those of the VMQ. However, the FVMQ offers better resistance to fuels and mineral oils. However, resistance to hot air is not as good as that of the VMQ.
Chemical resistance | Aromatic mineral oils (IRM 903 oil) Fuels Aromatic hydrocarbons with low molecular weights (benzene, toluene) |
---|---|
Temperature range | -70°C/+175°C |
HNBR (Hydrogenated Nitrile Butadiene Rubber)
This HNBR-based rubber is obtained through selective hydrogenation of the NBR's butadiene groups. It is commonly used for power-assisted steering and for air conditioning.
Chemical resistance | Aliphatic hydrocarbons Mineral and vegetable oils and greases Fire-resistant fluids (HFA, HFB and HFC) Diluted acids, saline solutions and bases for operation at an average temperature Water and steam up to +150°C Atmospheric and ozone agents |
---|---|
Compatibility issue | Chlorinated hydrocarbons Polar solvents (ketones, esters and ethers) Strong acids |
Temperature range | -30°C / +150°C (short-term peak at +160°C) -40°C / +150°C with particular HNBRs |
NBR (Nitrile Butadiene Rubber)
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 (short-term peak at +120°C) -40°C / +100°C with particular NBRs |
VMQ (silicone rubber: methyl vinyl polysiloxane)
This FVMQ-based rubber is very often used in fuel systems.
Chemical resistance | Animal and vegetable oils and greases Water for operation at an average temperature Diluted saline solutions Atmospheric and ozone agents |
---|---|
Compatibility issue | Superheated steam up to +120°C Chlorinated hydrocarbons with a low molecular weight (trichlorethylene) Aromatic hydrocarbons (benzene, toluene) |
Temperature range | -60°C / +200°C (short-term peak at +230°C) |
The table below gives an overview of the physical, chemical and mechanical characteristics for each of the materials.
Characteristics/Materials | ACM | AEM | CR | EPDM | FFKM | FKM | FVMQ | HNBR | NBR | VMQ |
---|---|---|---|---|---|---|---|---|---|---|
Abrasion resistant | 2 | 3 | 2 | 2 | 4 | 2 | 4 | 2 | 2 | 4 |
Resistance to acids | 4 | 3 | 2 | 2 | 1 | 1 | 3 | 1 | 3 | 3 |
Chemical resistance | 4 | 2 | 2 | 1 | 1 | 1 | 1 | 2 | 2 | 2 |
Resistance to cold | 4 | 2 | 2 | 2 | 3 | 4 | 2 | 2 | 2 | 2 |
Dynamic properties | 3 | 3 | 3 | 2 | 3 | 2 | 4 | 1 | 2 | 4 |
Electrical properties | 3 | 3 | 3 | 2 | 1 | 4 | 1 | 3 | 3 | 1 |
Flame resistant | 4 | 4 | 2 | 4 | 1 | 1 | 2 | 4 | 4 | 3 |
Heat resistant | 1 | 1 | 2 | 2 | 1 | 1 | 1 | 1 | 2 | 1 |
Sealing water | 1 | 1 | 2 | 2 | 2 | 2 | 4 | 2 | 2 | 4 |
Oil resistant | 1 | 3 | 2 | 4 | 1 | 1 | 2 | 1 | 1 | 2 |
Ozone resistant | 1 | 1 | 2 | 1 | 1 | 1 | 1 | 2 | 4 | 1 |
Tearing resistant | 2 | 3 | 3 | 1 | 4 | 3 | 4 | 2 | 2 | 4 |
Traction resistant | 3 | 2 | 2 | 1 | 2 | 1 | 3 | 1 | 2 | 4 |
Water/vapour resistant | 4 | 4 | 3 | 1 | 2 | 3 | 3 | 1 | 2 | 3 |
Resistance to atmospheric agents | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 3 | 1 |
1. Excellent properties 2. Good properties 3. Average properties 4. Poor properties
Chemical compatibility
A "Chemical compatibility guide" catalogue can be downloaded from the Documentation section. You can also use our online "Chemical compatibility" tool free of charge.
These two tools give you the option of measuring the behaviour of our materials that come into contact with the majority of existing fluids. The data displayed is the result of rigorous testing of the ambient temperature and in consultation with previous publications. Test results are not fully representative due to the specific features of your application. The tests performed actually do not consider additives and impurities that may exist under the actual conditions of use, nor the potential elevation of temperatures. Other parameters can also alter the behaviour of our materials, such as the hardness, persistence, abrasion, etc. We therefore recommend performing your own tests to verify the compatibility of our materials according to your specific application. Our technical team can provide you with any additional information.
Conditions for use
Speed
The table below indicates the relationships between the linear speed, the rotation speed and the recommended material.
Linear speed calculation:
s (m/s) = [Ø shaft (mm) x speed (rpm) x π] / 60,000
Pressure
The shaft seals with a primary sealing lip and without a spring are used only in pressurised environments.
We recommend using shaft seals with springs for use in pressurised environments between 0.02 and 0.05 MPa (max).
For even higher pressures, we recommend using high-pressure SCHP - TCHP shaft seals which, because of their specific design (shorter sealing lip, thicker rubber membrane, metal cage closer to the shaft), can support pressures of up to 0.1 MPa with speeds reduced to 0.3 m/s.
Temperature
The table below indicates the temperature limits, depending on the materials and fluids used.
Media | Maximum temperature, depending on the materials | |||||||
---|---|---|---|---|---|---|---|---|
ACM | AEM | EPDM | FKM | HNBR | NBR | VMQ | ||
Mineral oils | Oils for motors | +130°C | +130°C | - | +170°C | +130°C | +100°C | +150°C |
Oils for gearboxes | +120°C | +130°C | - | +150°C | +110°C | +80°C | +130°C | |
Oils for hypoid gears | +120°C | +130°C | - | +150°C | +110°C | +80°C | - | |
ATF oils | +120°C | +130°C | - | +170°C | +130°C | +100°C | - | |
Hydraulic oils | +120°C | +130°C | +150°C | +130°C | +90°C | - | ||
Greases | - | +130°C | - | - | +100°C | +90°C | - | |
Fire-resistant fluids |
HFA group - Emulsion with more than 80% water | - | - | - | - | +70°C | +70°C | +60°C |
HFB group - Opposite solution (water in oil) | - | - | - | - | +70°C | +70°C | +60°C | |
HFC group - Polymer aqueous solution | - | - | +60°C | - | +70°C | +70°C | - | |
HFD group - Water-free synthetic fluids | - | - | - | +150°C | - | - | - | |
Other fluids | EL + L heating oil | - | - | - | - | +100°C | +90°C | - |
Air | +150°C | +150°C | +150°C | +200°C | +130°C | +90°C | +200°C | |
Water | - | - | +150°C | +100°C | +100°C | +90°C | - | |
Water for washing | - | - | +130°C | +100°C | +100°C | +100°C | - | |
Temperature range | Min. | -25°C | -40°C | -45°C | -20°C | -30°C | -30°C | -60°C |
Max. | +150°C | +150°C | +150°C | +200°C | +150°C | +100°C | +200°C |
The lip of the seal for the rotary shaft endures a higher temperature due to shaft rotation, and the significant pressure and friction on the mechanical parts. Good lubrication is therefore necessary to allow for a better release of heat and thus limits the temperature rise in the parts subjected to friction.
By definition, the temperature at the edge of the seal is raised when the rotation speed (and thus the linear speed) as well as the shaft diameter increases. The graph below gives an overview of the increase in temperature (in °C) at the point of contact on the sealing lip.
Fluids
Greases
Greases are generally applied to bearings etc. and require specific adaptation to provide favourable operating conditions for the rotary shaft seal. To prevent the lip of the seal from sustaining more significant pressures than planned, we recommend positioning the lip seal on one side of the bearing in such a way so that the lip is not prematurely destroyed. We also recommend reducing the rotation speed by 50% when lubricated, to ensure that less heat escapes during friction.
Aggressive fluids
It is critical to choose the correct material to better resist different aggressive fluids (acids, solvents, chemical products, etc.). For applications in a rotating environment, we recommend using materials such as FKM rather than NBR. For operations that are dry or use very little lubrication, and where the rubbers do not resist certain aggressive fluids, we advise you to use our PTFE seals for the rotary shaft.
Seal design
Tolerance for the outside diameter of the seal (ØD)
The table below indicates the pre-tightening for shaft seals on the housing diameter according to standard ISO 6194-1.
Bore diameter ØD1 (mm) |
Tolerances on the outside diameter ØD of the ring | Roundness tolerance | |||
---|---|---|---|---|---|
Apparent metal cage | Rubber coating | Coating with grooves | Apparent metal cage | Rubber coating | |
ØD1 ≤ 50.0 | +0.10 / +0.20 | +0.15 / +0.30 | +0.20 / +0.40 | 0.18 | 0.25 |
50.0 < ØD1 ≤ 80.0 | +0.13 / +0.23 | +0.20 / +0.35 | +0.25 / +0.45 | 0.25 | 0.35 |
80.0 < ØD1 ≤ 120.0 | +0.15 / +0.25 | +0.20 / +0.35 | +0.25 / +0.45 | 0.30 | 0.50 |
120.0 < ØD1 ≤ 180.0 | +0.18 / +0.28 | +0.25 / +0.45 | +0.30 / +0.55 | 0.40 | 0.65 |
180.0 < ØD1 ≤ 300.0 | +0.20 / +0.30 | +0.25 / +0.45 | +0.30 / +0.55 | 0.25% of ØD | 0.80 |
300.0 < ØD1 ≤ 500.0 | +0.23 / +0.35 | +0.30 / +0.55 | +0.35 / +0.65 | 0.25% of ØD | 1.00 |
500.0 < ØD1 ≤ 630.0 | +0.23 / +0.35 | +0.35 / +0.65 | +0.40 / +0.75 | - | - |
630.0 < ØD1 ≤ 800.0 | +0.28 / +0.43 | +0.40 / +0.75 | +0.45 / +0.85 | - | - |
Tolerance for the inside diameter of the seal (Ød)
Free and without constraint, the inside diameter of the sealing lip is always smaller than the diameter of the shaft. The pre-tightening or interference denotes the difference between these two values. Depending on the shaft diameter, the diameter of the sealing lip is generally considered to be less, between 0.8 and 3.5 mm.
Shaft design
Shaft material
Suitable materials are:
- ordinary C35 and C45 steels used in mechanical construction
- 1.4300 and 1.4112 stainless steels for sealing water
- sprayed carbide coatings
- graphite
- malleable cast iron
- materials with a CVD and PVD coating
Not appropriate:
- chrome coatings solidified through non-uniform wear
- plastic materials resulting from low thermal conductivity, which can lead to a disturbance in the transport of heat, an increase in temperature in friction areas with the shaft seal, as well as a potential softening
Shaft hardness
Shaft hardness will depend on the linear speed (in m/s) and the level of pollution.
Rotation speed | Hardness in HRC |
---|---|
s ≤ 4.0 m/s | 45 HRC |
4.0 < s ≤ 10.0 m/s | 55 HRC |
s > 10.0 m/s | 60 HRC |
Surface roughness
The recommendations below must be considered for the quality of the shaft surface area.
Standard conditions:
- Ra = 0.2 to 0.8 µm and 0.1 for demanding applications
- Rz = 1.0 to 4.0 µm
- Rmax ≤ 6.3 µm
Shaft tolerance
The shaft must have a tolerance of h11, in line with standard ISO 286-2
Shaft diameter Ød1 (mm) |
Tolerance h11 (mm) |
---|---|
Ød1 ≤ 3.0 | -0.060 / 0 |
3.0 < Ød1 ≤ 6.0 | -0.075 / 0 |
6.0 < Ød1 ≤ 10.0 | -0.090 / 0 |
10.0 < Ød1 ≤ 18.0 | -0.110 / 0 |
18.0 < Ød1 ≤ 30.0 | -0.130 / 0 |
30.0 < Ød1 ≤ 50.0 | -0.160 / 0 |
50.0 < Ød1 ≤ 80.0 | -0.190 / 0 |
80.0 < Ød1 ≤ 120.0 | -0.220 / 0 |
120.0 < Ød1 ≤ 180.0 | -0.250 / 0 |
180.0 < Ød1 ≤ 250.0 | -0.290 / 0 |
250.0 < Ød1 ≤ 315.0 | -0.320 / 0 |
315.0 < Ød1 ≤ 400.0 | -0.360 / 0 |
400.0 < Ød1 ≤ 500.0 | -0.400 / 0 |
Chamfer and radius
You are strongly advised to install a chamfer on the shaft so as not to alter the primary sealing sealing lip of the shaft seal during assembly. Please refer to the table below.
Shaft diameter Ød1 (mm) |
Chamfer diameter Ød3 (mm) |
Radius R (mm) |
---|---|---|
Ød1 ≤ 10.0 | Ød1 - 1.50 | 2.00 |
10.0 < Ød1 ≤ 20.0 | Ød1 - 2.00 | 2.00 |
20.0 < Ød1 ≤ 30.0 | Ød1 - 2.50 | 3.00 |
30.0 < Ød1 ≤ 40.0 | Ød1 - 3.00 | 3.00 |
40.0 < Ød1 ≤ 50.0 | Ød1 - 3.50 | 4.00 |
50.0 < Ød1 ≤ 70.0 | Ød1 - 4.00 | 4.00 |
70.0 < Ød1 ≤ 95.0 | Ød1 - 4.50 | 5.00 |
95.0 < Ød1 ≤ 130.0 | Ød1 - 5.50 | 6.00 |
130.0 < Ød1 ≤ 240.0 | Ød1 - 7.00 | 8.00 |
240.0 < Ød1 ≤ 500.0 | Ød1 - 11.00 | 12.00 |
Shaft run out and eccentricity
The shaft run out is a deviation between the current shaft axis and the theoretical rotation axis. It is important to reduce the shaft run out as much as possible by positioning the shaft seal as close as possible to the bearing.
The shaft and housing must be assembled centred on one another in order to remove any unilateral radial load at the sealing lip of the ring.
Shaft machining
Correct shaft machining is essential to the proper operation of the sealing system.
- Plunge grinding: preferred machining method that ensures the absence of striations on the shaft (0 +/- 0.05°)
- Turning: suitable for shafts used with a unidirectional sense of rotation
Machining guidelines for surface adjustments
Parameters | Requirements |
---|---|
Speed of the part to be machined | 30 to 300 rpm |
Wheel speed | 1500 to 1700 rpm |
Surfacing feed | < 0.02 mm/turn |
Dressing tool | multi-grain dressing diamond, single drain dressing diamond |
Grinding rate feed | approximately 0.02 mm |
Spark duration | full spark, min. 30 secs |
Passing depth | > Rmax of the old machining operation |
Eccentricity of the tool and part to be machined | the best possible |
Housing design
Tolerance of the bore diameter of the housing
The bore diameter of the housing must have a tolerance of H8, in line with standard ISO 286-2
Bore diameter ØD1 (mm) |
Tolerance |
---|---|
3.0 < ØD1 ≤ 6.0 | 0 / +0.018 |
6.0 < ØD1 ≤ 10.0 | 0 / +0.022 |
10.0 < ØD1 ≤ 18.0 | 0 / +0.027 |
18.0 < ØD1 ≤ 30.0 | 0 / +0.033 |
30.0 < ØD1 ≤ 50.0 | 0 / +0.039 |
50.0 < ØD1 ≤ 80.0 | 0 / +0.046 |
80.0 < ØD1 ≤ 120.0 | 0 / +0.054 |
120.0 < ØD1 ≤ 180.0 | 0 / +0.063 |
180.0 < ØD1 ≤ 250.0 | 0 / +0.072 |
250.0 < ØD1 ≤ 315.0 | 0 / +0.081 |
315.0 < ØD1 ≤ 400.0 | 0 / +0.089 |
400.0 < ØD1 ≤ 500.0 | 0 / +0.097 |
500.0 < ØD1 ≤ 630.0 | 0 / +0.110 |
Groove width dimensions
The table below provides information on the width of the groove and the recommended radius.
Height H1 |
Width | Radius Max R2 |
|
---|---|---|---|
L2min (H1 x 0.85) | L1min (H1 x +0.3) | ||
7.00 | 5.95 | 7.30 | 0.50 |
8.00 | 6.80 | 8.30 | |
10.00 | 8.50 | 10.30 | |
12.00 | 10.30 | 12.30 | 0.70 |
15.00 | 12.75 | 15.30 | |
20.00 | 17.00 | 20.30 |
Only on request