A Technical Guide to Choosing O-Rings
A Technical Guide to Choosing O-Rings
TECHSiL are proud to be a preferred distributer of Trelleborg Sealing Solutions for O-Rings and Bonded Seals. O-Rings are used across all industries for sealing applications, meaning there are lots of considerations to assess before choosing the correct O-Ring.
Why is Choosing the Right O-Ring Important?
If an incompatible material is chosen or the O-Ring is made to the wrong dimensions then damage and leakages can occur, costing money, time, and even safety hazards. Industry standards also have to be considered when choosing the appropriate material for the O-Ring to be developed from. Lastly the installation process must be considered otherwise the O-Ring could be damaged during manufacturing, creating a loose seal and reducing the longevity of equipment.
What should be considered when choosing an O-Ring?
Material Selection – What material is compatible for the application?
- Types of materials used include elastomers, metal, polyurethane, or PTFE
- Application parameters
- Temperature and environmental conditions
- Mechanical properties required i.e. hardness or flexibility
- Medium to be sealed
- Working pressure
- Type of use - static or dynamic seal
- Chemical resistances, contact with fluids like oil or lubricants
- Applicable standards or approvals (e.g. defence standards and institutional approvals for drinking water application)
Housing Layout - What dimensions are needed for the seal?
- If the O-ring is too small, the seal won’t be efficient, too big an O-Ring and it’ll be hard to install
- Initial compression of the O-Ring
- Surface finish of the groove diameter, groove flanks and the mating surface
- Groove width, height, and design
- Housing height
- Radial clearance (sealing gap)
- Elongation - Outside diameter interference of the O-Ring; Groove fill; Tolerances
- Method of O-Ring installation/type of use - Axial (static) or Radial (dynamic or static)
- Rounded edges and lead-in chamfers for easier installation
O-Ring Quality - Are there specific standards which need to be met?
- Required standards vary by country and industry i.e. military or government grade standards
- Dimensional tolerances - Inside diameter, Cross section ISO 3601-1 is recommended
- ISO 3601 is the international standard
Correct O-Ring Installation - How will the O-ring be installed?
- Level and speed of stretching
- O-Ring Twisting – lubrication, assembly tools
- O-Ring damage - usage and design of assembly tools
Why Choose TECHSiL?
TECHSiL are proud to be a preferred distributor of Trelleborg Sealing Solutions for O-Rings and bonded seals, offering high performance solutions across industries. Specifying the right O-Ring for the required application can be difficult, reach out to our Technical Team today for advice and more information!