The Integral Role Seals Play in Engineering and Design

Engineering and designing of any kind is filled with variables. Any process that requires a seal to ensure that no fluid or material escapes has its own set of unique design challenges. When designing a system, it’s important to remember every force and factor acting upon the seal, otherwise it could lead to catastrophic failure.

Product Pressure

With any application of a seal, pressure is a concern. If the wrong seal is chosen, pressure can cause product to escape. Under extreme pressures, if the seal is incorrectly chosen, it will simply break and cause complete failure. A seal should be able to withstand the entire range of pressures a system may undergo during different phases and with shifting loads. As pressure increases, the fluid film becomes thinner (this means more friction on the seal) – and the inverse is true, as well; lower pressure means a thicker film.

When prototyping, it’s important to run at the highest ranges so that you know exactly what ranges are required of your seals. The seal should be able to withstand the peaks and valleys of the system. High pressure systems need to be extremely vigilant about maintaining a tight seal, as contaminants have a much higher impact upon these systems due to their higher velocity, thus increased friction and damage.

System Load

Seals must be able to withstand the forces of the system that they are sealing. In order to maintain alignment and proper guidance of the piston, rod, or other moving part, it is essential to choose a seal with a high enough load bearing capacity. When prototyping, it’s important to factor in the entire force of the application, not just isolated pieces. The cumulative effect of a system can be much higher when put together and not just piece by piece.

Temperature

The temperature of a seal comes from a myriad of places including: product, environmental conditions, and friction. Simply knowing how much heat a system outputs is not enough. It’s vital to know the entire set of factors when selecting a seal. The range of temperature is also important to consider, as a high variance will alter the seal’s ability to maintain its shape.

High heat, of course, deforms and melts seals, but low temperatures also have negative impact upon the seal. Always account for environmental conditions when it comes to seals, especially for outdoor applications: rain, snow, or intense heat are all going to have an effect on the seal and the system it is attached to, requiring a wide range of temperature tolerance. Again, it is not enough to have just the isolated pieces tested; the entire system must be taken into account when it comes to heat.

Velocity

The speed at which any given system operates is a huge factor in sealing. Not only does it affect the wear and tear of a seal, but also the temperature due to friction. Fluid properties can also be altered during speed changes and high speed environments, causing alterations in the fluid film. Systems that have a variance of speed can undergo rapid changes in pressure or temperature, requiring durable seals with high ranges of tolerance.

Chemical Properties

Perhaps the most specialized area of sealing is the various chemical requirements of different systems. Some seals will wear down when exposed to acids, oils, and all kinds of chemicals. Just because a seal is solid doesn’t mean it can’t have a reaction with the fluid it is housing. Also, seals must be able to keep out any unwanted contaminants; some products simply can’t have water enter the system, while others need a barrier against biological contaminants.

Expertise

When it comes to design and engineering, seals play an integral role; if only one of these many factors aren’t taken into account, catastrophic failure can occur, causing major loss in product and damage to machinery. Make sure to work with an expert in sealing and the materials seals are made of when designing any system. Real Seal has years of experience designing solutions for all kinds of applications. Contact Real Seal today to ensure your systems are properly sealed.