Although technology is always evolving, certain things remain timeless. One of these items is the O-Ring, which was initially patented in 1896. What is an O ring seal? It is a doughnut-shaped loop intended to prevent liquids or gases from passing through it. It is one of the simplest precision mechanical parts ever created and remains one of the most extensively used sealing goods.
O Ring Seal Basics
An O Ring, sometimes known as a “torus,” functions in conjunction with the glands in which it is inserted. Normally, the gland is cut from the metallic hardware and seals with the O-ring. To ensure optimal functioning, the gland and O-ring must be developed together. O-Rings can be constructed of plastic or metal, but for the sake of this article, we’ll only discuss rubber – or elastomeric O-Ring design.
How does an O ring seal work?
Seals keep fluids from leaking via the spaces between mated parts of hardware. When a gland is at rest, the O-Ring sits in the center, but when pressure builds up in the sealing system, the O-Ring moves to the other side. Because the material is soft, the O-Ring is mechanically compressed to fill the gap between the two mating hardware components.
Advantages of O-ring Seals
Chemical compatibility is frequently one of the first considerations when selecting an O-Ring material.
Corrosion Resistance
When dealing with media that is incompatible with normal rubber compounds, as well as caustic or corrosive substances, PTFE is the ideal material choice. PTFE is impermeable to nearly all industrial solvents, making it one of the most corrosion-resistant materials accessible in any industry. And if chemical assault threatens the integrity of rubber composites, PTFE may be the solution.
Long shelf life.
Applications needing long-life or prolonged service intervals in corrosive conditions may also benefit from the usage of PTFE. While certain elastomers may survive in the near term or in intermittent exposure, deterioration over time might cause difficulties years later, whereas PTFE’s resistant qualities will continue permanently.
Wide temperature range capability.
Most elastomers cannot withstand temperatures ranging from -325°F to +500°F, while PTFE does. Applications in cryogenics or high temperature environments, such as ovens or combustion processes, may rule out any elastomer compound, making PTFE the ideal option.
Most rubber compounds will harden to the point that they lose their elastomeric qualities when exposed to extremely low temperatures. This, paired with material contraction, may result in the seal no longer functioning efficiently. In contrast, even at cryogenic temperatures, PTFE retains its flexural and pliability qualities.
Limitations of O Ring Seal Use
Although it has been stated that O-Rings offer a reasonable approach to the ideal hydraulic seal, they should not be considered an immediate solution to all sealing problems. There are still fundamental limits to employing O-Rings as a primary seal. These restrictions include:
- Rotary speeds exceed 1,500 feet per minute.
- Improper mating hardware design.
- Incompatible temperature, pressure, and fluid chemical compatibility.
Disadvantages of O ring seals
While chemical attacks or severe temperatures may leave you with no choice but to use PTFE, the material does have several drawbacks that may impair your project.
Higher hardness.
The hardness of virgin PTFE is 55 Shore D, which is significantly higher than that of a normal Nitrile O-Ring, which is 70 Shore A on a softer scale. Higher hardness reduces sealability because the material does not adapt to the mating hardware surfaces as easily.
Leakage Rate
While rubber O-Rings may adapt to “as machined” surfaces, PTFE may need post-process surface quality modifications to reduce leakage to acceptable levels. Under typical conditions, an O-Ring leaks more than any other elastomeric compound. The use of a PTFE O-Ring is not suggested for applications that do not need high temperatures or harsh chemical conditions.
Conclusion
O-rings provide several advantages in a variety of sectors, including aerospace, automotive, chemical, and food and beverage, to seal diverse components that require high-performance sealing solutions. If you need a high-performance sealing solution, explore our O-ring seals options on the website.
Horiaki India Private Limited
Horiaki India Private Limited was established in the year 1998 with an aim to manufacture and supply premium rubber bonded products in India as well as the international market.