O-Rings are commonly used sealing elements in automotive, machinery and other industrial areas for it’s assembling facility, simple shape and low cost. They are suitable for both dynamic and static applications.
Using O-Rings provides some certain advantages. Like:
- Low costs,
- Savings from space. Requiring less volume than other sealing elements which work identical,
- Sealing on both sides,
- Requiring less experience on assembling, without dangerous state on reverse aseembling,
- Easy machining of O-Ring grooves,
- Being used more efficiently on low tolerated surfaces than other gaskets on static working.
Operation Features
Sealing efficiency of O-Ring is based on the axial and radial deformation while assembling occurs. This deformation can be found with optimized design of the housing. The ensuing reaction force of rubber gives the contact pressure which is necessary for sealing, and this is additionally supported by the pressure of media.
O-Ring’s material acts like a type of fluid which viscosity is very high. If the radial space between the sealing surface and groove corners is too much and pressure at which O-rings can work without extrusion failure is therefore controlled by the hardness of the O-ring and the working gap. If there won’t be any leaking clearance and O-Ring will be used in static conditions there is not an exact pressure rate to resist.
It is simple to scale the O-Ring grooves. While scaling, it is needed to be careful about groove heights for defining ratio of compression. There are types of O-Ring grooves like; dynamic (hydraulic and pneumatic), radial compressed, axial compressed (static), triangle and trapeze.
The hardness of O-Ring material changes between 60 to 90 Shore A. While soft materials (60 Shore A) are suitable for ensuring a better sealing at low pressure (static operations <160 bar, dynamic operations <63 bar), harder materials (90 Shore A) are suitable for sealing at high pressure (static operations >160 bar, dynamic operations >63 bar). Common used O-Rings have 70 Shore A hardness.
Pressure and operation clearance are the major factors at determining the hardness or O-Ring. It is suitable to use a harder material when pressure and operation clearance increases.
Assembling Suggestions
- The place (table etc.) that assembling will be on, must be clean.
- There must not be any dust, dirt etc. on the part or O-Ring that will be assembling.
- Suitable oilers and lubricants must be used, after searching elastomer’s reaction to them.
- O-Ring must not be harmed of the rolling during the assembling.
- There must not be any sharp edges, parts or holes around the are that O-Ring will be mounted.