Tag Archives: seals

How Temperature and Pressure Affect Seal Performance

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Small components, such as seals, play a major role in keeping industrial systems running smoothly. Whether it is an HVAC unit, a hydraulic system, an automotive engine, or a manufacturing line, seals, including specialty seals designed for demanding applications, prevent leaks, maintain pressure, and protect equipment from contaminants. To prevent breakdowns, minimize downtimes, and extend the life of your machinery, it is important to understand how temperature and pressure affect seal performance.

How Temperature and Pressure Affect Seal Performance

Temperature

One of the biggest factors that influences how well a seal performs is temperature. Regardless of material, whether rubber, silicone, PTFE, nitrile, or fluorocarbon, there is a specific temperature range in which it works best. Working outside this window can cause rapid deterioration.

1. Heat Can Accelerate Material Degradation: High temperatures cause seal materials to weaken over time. Sustained exposure to heat can lead to:

  • Softening – can result in extrusion under pressure
  • Hardening – makes the seal brittle and prone to cracking
  • Loss of elasticity – results in poor sealing performance
  • Chemical breakdown – particularly in oils, fuels, and chemical processing applications

For instance, a nitrile seal is expected to perform excellently at moderate temperatures. But in a high-heat environment like that found in engine components, it can quickly degrade.

2. Cold Temperatures Can Cause Shrinkage and Embrittlement

Low temperatures can make many materials rigid. This can cause:

  • Seal shrinkage, which can lead to gaps
  • Reduced flexibility, reducing the seal’s ability to maintain contact
  • Cracking, especially when there are rapid temperature drops

3. Rapid Temperature Changes Leading to Thermal Shock

Frequent heating and cooling may cause seals to expand and contract repeatedly. This can cause stress on the material, reduce its lifespan, and increase the risk of leaks. Compressors, industrial ovens, and similar systems should therefore use seals that withstand thermal cycling without deformation.

Pressure

You want your seals to maintain a tight, leak-free barrier. Pressure is the determining factor in how well your seals perform. However, while there are specific temperature ranges, they are also designed for specific pressure ranges. Exceeding those limits can mean failure. 

  1. High pressure Can Lead to Extrusion: When seals are exposed to pressure that they are not designed to withstand, the material can be pushed or extruded, resulting in:
    • Material deformation
    • Rapid wear
    • Complete seal blowout
  2. Low Pressure Can Lead to Insufficient Seal Compression: Low pressure can prevent seals from fully compressing, leading to leaks. This is common in pneumatic systems, such as industrial automation, dental drills, air brakes on buses and trains, and tools like nail guns.
  3. Pressure Fluctuations Increase Wear: Pumps, valves, hydraulics, and other equipment that frequently switch between high and low pressure require seals with high resistance and durability.

Combined Effects of Temperature and Pressure Together

Real-world operations usually require simultaneous temperature and pressure. The problem with them working together is that their effects are amplified.

  • High temperature + high pressure: This leads to the acceleration of chemical and mechanical wear
  • Low temperature + high pressure: Low temperature makes seals less flexible and slightly shrinks. This is when the seal can easily crack or split in high temperatures because it cannot deform to relieve stress.
  • Wide temperature fluctuations + pressure changes: This creates complex stress patterns that lead to loss of elasticity, material fatigue, microcracks, and leakage. 

How to Improve Seal Performance in Varying Conditions

Here are some steps you can take to help ensure seals last as long as possible.

  • Choose the appropriate material for both temperature and pressure ranges.
  • Use backup rings for high-pressure applications.
  • Avoid exposing seals to sudden extreme temperature shifts if you can help it.
  • Follow the manufacturer’s instructions and recommendations.
  • Schedule a regular inspection to catch wear and hardening before they become bigger problems.

Ensure Your Machinery Performs at Its Best

Seals may be small, but they have a big role in ensuring that your systems work smoothly. Two of the most critical factors that affect their performance are temperature and pressure. By understanding how they influence material behavior, you can choose the right seal materials for the operating environment.

If you have a machine that operates under demanding temperature and pressure conditions, selecting the right sealing solution is crucial. Whether you are looking for durable elastomers, specialty seals, or an engineered thermoplastic mechanical component designed for extreme environments, we will help you find the perfect match for your application. 

Make sure your machine performs at its best, no matter the condition. Contact us today to get expert guidance.

Engineering & Design Support – What exactly does this mean?

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Engineering is defined as “The creative application of scientific principles to design or develop structures, machines, apparatus, or manufacturing processes, or works utilizing them singly or in combination; or to construct or operate the same with full cognizance of their design; or to forecast their behavior under specific operating conditions; all as respects an intended function, economics of operation or safety to life and property”.  As products become more intricate, detailed, and performance specific, the discipline of engineering has become more specialized.  Technological innovation, advances in processing, and ever present economic changes make it extremely difficult to remain on the cutting edge of all of the technologies that drive OEM products.  As OEM’s feel growing pressure to reduce engineering costs, the prevalent result is to turn to suppliers for support.  While engineering support can take many forms, Real Seal supports customer engineering primarily with:

  • Materials Engineering
  • Design Engineering
  • Design for Tooling
  • Design for Assembly

Materials Engineering – With a polymer chemist on staff, Real Seal has supported and developed hundreds of materials for specific applications.  Most of the applications reflect the market, with modified versions of primary materials, designed to meet specific criterion for performance enhancement.  Recently developed materials include an EPDM rubber material designed to meet water purification regulatory requirements, but with enhanced tear strength; a polyurethane material with enhanced physical properties as well as processing improvement; an HNBR material which exhibits the same physical properties as conventional, but with reduced cost.  Real Seal can offer these enhanced material options with relatively little cost, and normally achieve results in a fraction of the time it would take large manufacturers.

Design Engineering – Rubber and plastics are unique materials, and behave differently in applications than one may expect.  Real Seal has been instrumental in numerous applications with design suggestions that have improved the dynamics, longevity, and efficiency of OEM products.  Using the latest CAD 3D software, Real Seal creates virtual models of the application and components, and highlights the relative positioning, location, and dynamics of the application in its desired use.

Design for Tooling – Real Seal has entertained numerous projects where a review of the tooling necessary to meet design criterion can be modified to save considerable money on tooling costs.  The intricate aspects of tool design, including gate locations, parting lines, radii as opposed to sharp corners, and symmetry wherever possible can make a difference of thousands of dollars in tooling costs, depending on the intricacy of the design and number of cavities.

Design for Assembly – We have experienced numerous situations where the application engineering is on target, but when the part is supplied, engineers responsible for final assembly of the completed product struggle.  This may be due to an inability to locate or position the part properly in the assembly, or it could be as simple as not considering right hand and left hand versions of the design, which must be clearly identified to avoid confusion when the components make their way to final assembly.  Real Seal has the experience and resource base to make suggestions that would impact these considerations, which may add considerable value.

You can see more detailed video articulation of these concepts on our website (www.real-seal.com), and always feel free to contact us here at Real Seal.