When deciding what kind of seal is best for a given application, it’s best to choose one that will last the longest. It’s impossible to tell exactly how long a seal will last, but knowing what forces wear down seals – and the materials that best stand up to such forces – will ensure that your seals have the longest life possible.

Sometimes it’s possible to extrapolate a general idea of how long a seal might last based on similar applications, although this is only educated speculation. The only way to find out how long a certain seal will last for sure is to put it into a specific application and measure how long it takes for the seals to fail, plus averaging it out over time. The high end of this spectrum tends to be around three years, with some extremely hostile operations being much shorter. Allowing a seal to run until it fails can lead to catastrophic consequences, major failure, and loss of product. It’s imperative to err on the side of caution when it comes to replacing seals.

Shelf life is another story. Most seals have an expected shelf life that can be much more accurate than application life duration estimates. Higher quality seals will degrade much slower over time than cheap knock-offs. Rubbers tend to have a shelf life of around fifteen years. Fluorocarbons and silicone have much longer shelf lives, degrading much slower than any timeline relevant to business.

The most common reasons and forces that act upon seals leading to failure and shorter lifespans are much more readily available and preventable than guessing a given seal’s life span in a certain application.

Initial Failure

If a seal fails much quicker than expected, chances are the wrong seal was chosen. When selecting a seal, it’s imperative that the correct material is chosen. Many of the fluids seals must contain within their systems are corrosive or reactive to certain seal materials, causing the seals to weaken much faster than they should. This is not the only reason for a quick failure. It also me be the wrong shape, size, or design for the application. If a seal is designed for static applications and put into a dynamic operation, it will fail much faster than intended. This is why it is so important to have an expert on seals guide you through the selection process, as these failures can be extremely costly due to the loss of product, damaged machinery, and lost time.

Random Failure

A random failure typically happens when the conditions surrounding a seal change. The most common cause of this failure is a kind of mechanical or procedural failure that precipitates a large amount of strain on the seal. A rapid increase in pressure, temperature, or physical force on the seal could all be a cause. These issues are more of a mechanical problem than a sealing problem; unless these changes are routine and expected, then the seal must be able to withstand both ranges of force.

These types of failures can also be caused by environmental factors. If the place in which the machine is located is exposed to the elements, then a change in seasons or weather can have a large impact on a seal’s ability to withstand the forces acting upon it.

Wear Failure

A seal that degrades over time in a predictable way is the aim of all operations. If a seal has a relatively predictable lifetime, then it can be replaced to prevent failure and there is no loss outside of the small amount of time it takes to change the seal.

Finding the Right Seal

All of this comes down to finding the best seal for your application. Heat, pressure, chemical composition, and other factors all play a role in how long a seal might last, so it’s best to have an expert who knows how to compensate for the myriad forces acting on a seal. Real Seal is an expert in the sealing business and will be able to point you to or design the seal that has the best potential for a long lifespan in your application. Contact Real Seal today to find the right seal for your operations.

Any manufacturing operation that moves product through some kind of tubing requires a seal. With so many variables in each operation, sometimes it seems that no individual seal will fit the wide range of requirements; that’s where specialty custom seals come in. Real Seal has expertise in creating unique solutions for equally unique problems, ensuring quality operations and results. Specialty seals are designed to meet different engineering challenges with unique shapes and design.

X-Rings

Standard o-rings have a circular cross section, creating a large mating surface. In some operations with low speed oscillation or reciprocation the basic o-ring may twist, which can cause leakage and damage to the ring as well as the surfaces it is mated to.

When pressure is exerted upon the x-ring, four contact points are made due to the x-shaped profile. Because of the x-ring’s design, it requires less compression to seal the surfaces it is attached to. Another advantage is that the seam of the x-ring is between its mating surfaces; some o-rings may have leakage problems in this parting section, but with x-rings this problem is virtually eliminated.

Most commonly used in reciprocating applications, x-rings have reduced friction and have a better durability and anchoring for this kind of motion. In some rotational settings a normal o-ring will also experience warping, x-rings are recommended for these applications, as well. To ensure quality operations in reciprocating and rotational operations use these kinds of specialty rings.

Square Rings

Originally, square rings were designed as a cheaper alternative to o-rings, but as the cost of o-rings has fallen square rings have been out-competed in dynamic operations. Square rings do still have their place in static operations or in places where costs must be kept to an absolute minimum. Static sealing with a square ring is perhaps the most effective when a high load force is required. Square rings are not recommended for operations with movement, as they are more prone to failure. So, in high load static operations specialty square rings will make sure that your operation is producing top quality.

Back-up Rings

Back-up rings aren’t used all on their own, but in conjunction with other seals, usually o-rings, to prevent extrusion and leakage. In high pressure applications a more rigid back-up ring is used to hold the o-ring in place while allowing it to continue to do its job of preventing leakage. Some back-up rings can also increase the temperature resistance for the o-ring, as well as friction resistance. Back-up rings are extremely important because they allow for more solutions in an application having issues with o-ring failure without having to retool the entire machine to compensate. Most back-up rings are designed to fit standard o-ring sizes, but more specialized back-up rings can be used for other kinds of sealers than o-rings, too. If your operation is suffering due to extrusion or leakage, a back-up ring can increase the quality and durability of your seal.

U-Rings and V-Rings

U-rings and V-rings are similar to o-rings in design, but have a U or V shaped groove in the counter-face of the ring. These rings have reduced wear and friction due to their unique shape, plus they can fit in some uniquely shaped joints that require a nonstandard sealing shape. Due to the groove in the ring some of these rings are also designed to reduce contamination and leakage.

O-Ring and Specialty Ring Experts

No matter what kind of application, Real Seal will have the expertise to point you in the direction of the correct type of sealing ring. Their twenty plus years of experience has given them the experience they need to make sure your operation is running at the highest quality and safety. They can make recommendations based on your needs and even design specialty custom rings if the operation calls for it. Contact Real Seal today!