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Types of O-Ring Seals: What You Need to Know

How much do you know about the types of O-ring seals, specifically profile rings? It’s ideal to gain more knowledge or refresh your memory. Below, you’ll find more details about its benefits.

Types of O-Ring Seals: What You Need to Know - KB Delta

In the industry world, there are many different parts and equipment that each play a vital role in the operation of a machine. Some parts are very different from each other, but many are quite similar in terms of the shape, such as sealing rings or O-rings. One of the many variations of O-rings is the profile ring.

Here, we’ll take a closer look at this specific O-ring seal, how to find the right one, and when replacement is necessary.


What is a Profile Ring?

Profile rings are generally small, circular rings made of various materials. Some of these include:

  • PEEK
  • Carbon PEEK
  • MT
  • Nylon

These thermoplastic rings are made using lathes, mills and only with the latest in technology. Because of the method in which they are created, profile rings are able to work exceptionally well, even into extremely high temperatures. They perform their proper jobs in this high heat in both chemical and mechanical fashions.


What Do They Do?

With profile rings being made to order and custom cut to any needed size, they can accomplish many different functions. Their aerodynamic design enables them to create a superior seal in many hydraulic applications, such in hydraulic presses, construction machinery, valves and many other connections that involve threaded tubing.

With their innovative shape, profile rings are able to withstand intense pressure which makes them ideal in uncompromising situations. This also gives them the edge to accommodate for flaws in the machinery that they create the seal between, effectively keeping out steam and other liquids. This helps to ensure that the parts you are running will operate efficiently.


Finding the Right One

Profile rings are generally made to order with the person ordering giving exact specifications. The rings are then formed in an exceedingly precise manner to ensure the perfect fit, no matter what you are using them for.

Finding the size that you require can really only be done by someone with suitable knowledge and equipment experience. Having accurate and detailed measurements will get you the correct dimensions and will guarantee a flawless seal for whatever you might need.

When you think about it, the rubber in sealing rings is an amazing material. It is a recent discovery, only introduced in 1736. It was not until 1700 that Joseph Priestley developed rubber in its first commercial use as a pencil eraser.

The usefulness of rubber lies in its elasticity, defined as the ability of rubber to deform reversibly under stress. When placed between two highly inelastic pieces of metal, it deforms to form a seal that is highly impervious to liquid or gas passage, even under extreme temperatures and pressures.

Thermoplastics are a modern form of elastic sealing material which forms the basis of high-performance profile rings in compressors.


What Makes Them Fail?

Much like our skin, which is also highly elastic when we are young, thermoplastic material loses its inelasticity with age. This process is sped up in the presence of extreme temperatures or caustic materials.

In other words, aged profile rings lose the ability to return to its original form. This reduces its ability to form an effective seal.


Symptoms of a Failing Seal

In many systems, the first symptoms of a failing seal are a visible leak at the seal joint. In a compressor system, the symptoms are less obvious. One of the key symptoms is a loss of pressure.

Although this can be attributed to the age or degradation in several parts of the system, the most common point of failure is the system. For this reason, monitoring pressure is an excellent way to determine when profile rings need to be replaced.

Failing rings are not like a flat tire. They do not fail all at once. The effect of their degradation is more like a slow leak. For this reason, the technician who monitors pressure as a means to determine the useful lifetime should have a boundary failure level for pressure, one well in advance of the pressure requirements of the system.


Replace Them All

Thermoplastic failure in a particular system is highly predictable. When one seal begins to fail, the others will soon follow. For this reason, it is a good idea to replace seals at the first sign of degradation, or alternately, on a fixed time schedule.



It’s always best to understand the types of O-ring seals and how they exactly work. They provide many benefits when it comes to your manufacturing or product needs. With that said, working with an experienced company is key in order to produce high quality parts.


Types of O-Ring Seals: What You Need to Know - KB Delta

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