O-RING NBR 70 107,63 X 2,62

Product description:

• O-rings are closed, circular seals, the operation of which is based on the deformation of their cross-section
• O-rings are produced as continuous coils from elastomeric materials, such as NBR, FKM (Viton), EPDM etc., by vulcanisation in moulds
• The simple design and reliability of the sealing function of O-rings are ingenious
• O-rings are therefore the most widely used type of seal
• Their cost-effective manufacture and straightforward installation make O-rings unrivalled
• The specification of O-rings consists of the inner diameter and the cross-section thickness in mm, together with the material designation and its hardness

Standard material colour:

• EPDM 70, black
• FKM 75, green
• FKM 75, brown
• FKM 80, green
• FKM 80, brown
• FKM 80, black
• FKM 90, green
• FKM 90, black
• HNBR 70, black
• NBR 70, black
• NBR 80, black
• NBR 90, black
• VMQ 70, reddish-brown
• FKM/FEP, transparent/black
• VMQ/FEP, transparent/reddish-brown

Tolerances:

• In accordance with DIN 3771 / ISO 3601

Operating parameters:

• Temperature EPDM 70 Sulphur: -45 °C to +130 °C
• Temperature EPDM 70 peroxide: -50 °C to +150 °C
• Temperature (FKM): -15 °C to +200 °C
• Temperature HNBR: -30 °C to +150 °C
• NBR temperature range: -30 °C to +100 °C
• Temperature VMQ 70: -55 °C to +200 °C

Areas of application:

• O-rings are primarily used to seal stationary machine and plant components (static applications) against liquid and gaseous media, e.g. flange and cover seals, threaded pipe connections, and cylinder heads and bases in hydraulic cylinders
• Under certain conditions, O-rings can also be used in reciprocating and rotating movements (dynamic applications)
• With a professionally designed and well-constructed installation space and the correct choice of material, pressures of up to 1000 bar can be sealed
• Support rings may need to be used
• O-rings are used in numerous sectors, such as hydraulics, pneumatics, vacuum applications, the fittings industry, the automotive industry, as well as in mechanical engineering and plant construction

Mounting spaces:

• The installation spaces (grooves) for O-rings should, where possible, be cut rectangular and machined with care
• Burrs, scratches and nicks must be avoided
• The dimensions for the required groove depth and width depend on the application and the O-ring's strength
• Design tips and tables with dimensions can be found in our O-ring catalogue
• To facilitate installation, we can offer various surface treatments on request

Selection of groove depth and width:

• To achieve a good sealing function, you should select O-rings with the highest possible cord strength
• The hardness of the O-ring material to be selected depends on the pressure, the gap size, the sealing method (static/dynamic) and the surface quality of the machine components
• For standard applications, we recommend a hardness of 70 Shore A when selecting the material
• You should also ensure the correct pre-tension, elongation or compression, and groove fill

Materials:

• EPDM
  • EPDM materials are generally highly resistant to hot water, water vapour, ageing and chemicals, and enable a wide range of thermal applications
  • They are divided into sulphur- and peroxide-vulcanised types, with the peroxide-vulcanised types being able to withstand higher thermal loads and exhibiting significantly lower residual deformation
  • EPDM is highly resistant to hot water and water vapour, detergents, sodium and potassium alkalis, silicone oils and greases, many polar solvents, and many diluted acids and chemicals
  • Special compounds must be used with glycol-based brake fluids
  • EPDM materials are absolutely not resistant to mineral oil-based products (lubricating oils, motor fuels)
  • Permissible temperatures range from -45°C to +130°C (-50°C to +150°C for peroxide mixtures)
• FKM
  • FKM materials are characterised by their excellent resistance to high temperatures and chemicals
  • It should also be noted that they are highly resistant to ageing and ozone, have low gas permeability (making them very suitable for vacuum applications) and exhibit self-extinguishing fire behaviour
  • The standard FKM material for O-rings is highly resistant to mineral oils and greases, aliphatic, aromatic and chlorinated hydrocarbons, motor fuels, the flame-retardant fluids HFD and many organic solvents and chemicals
  • In addition to the standard FKM materials, various special compounds are available which, due to their different molecular structures and varying fluorine contents (65% to 71%), are ideally suited to specialised applications
  • FKM is generally not resistant to hot water, water vapour, polar solvents, glycol-based brake fluids and low-molecular-weight organic acids
• HNBR
  • HNBR is produced by the complete or partial hydrogenation of NBR
  • This significantly improves its heat, ozone and ageing resistance and results in very good mechanical properties
  • Its resistance to media is comparable to that of NBR
  • They are used at temperatures ranging from approximately -30 °C to +150 °C
• NBR
  • NBR is the most commonly used material for O-rings due to its good mechanical properties and resistance to mineral oil-based lubricants and greases
  • These properties are largely determined by the acrylonitrile content (ACN between 18% and 50%)
  • A low ACN content results in good flexibility at low temperatures but limited resistance to oils and motor fuels; as the ACN content increases, flexibility at low temperatures decreases whilst resistance to oil and motor fuel increases
  • Dichtomatik's standard NBR material for O-rings has a medium ACN content, covering a wide range of applications
  • This material possesses good mechanical and processing properties, e.g. high wear resistance, low gas permeability and good resistance to mineral oil-based lubricating oils and greases, hydraulic oils H, H-L, H-LP, flame-retardant fluids HFA, HFB, HFC, aliphatic hydrocarbons, silicone oils and greases, and water up to approx. 80°C
  • NBR is generally not resistant to aromatic and chlorinated hydrocarbons, motor fuels with a high aromatic content, polar solvents, glycol-based brake fluids and the flame-retardant fluids HFD
  • NBR is less resistant to ozone, weathering and ageing
  • In the vast majority of applications, however, this has no adverse effect
• VMQ
  • Silicone compounds are characterised by their wide range of thermal applications and their excellent resistance to ozone, weathering and ageing
  • The mechanical properties of silicone are inferior to those of other elastomers
  • In general, silicone materials are non-toxic; they are used, for example, in the food and medical industries
  • Standard silicone material can be used at temperatures ranging from -55°C to +200°C and is resistant to water (up to 100°C), aliphatic engine and gear oils, animal and vegetable oils and fats
  • Silicone is generally not resistant to motor fuels, aromatic mineral oils, water vapour (brief exposure up to 120°C is possible), silicone oils and greases, acids and alkalis

Fitting:

• During installation, care must be taken to avoid any damage to the O-ring, as this may otherwise lead to leaks
• Furthermore, the following guidelines must be observed:
  • The O-ring must not be stretched to its yield point
  • Edges must be free of burrs; rounded sections and chamfers must be fitted seamlessly
  • Dust, dirt, metal shavings and other particles must be removed
  • Sharp points on the thread and installation spaces for other seals and guide elements must be covered using a mounting sleeve
  • Mounting surfaces and O-rings must be lubricated with a suitable grease
  • Heating in oil or hot water to approx. 80°C makes elastomers more pliable. This makes it easier to stretch the O-ring for fitting
  • Any fitting tools, such as mandrels or sleeves, must be made of a soft material (e.g. POM) and must not have any sharp edges
  • The O-ring must not be rolled over the mounting surfaces. When fitting into the groove, the O-ring must not twist