Seals help ensure safe, efficient, and leak-free operations, particularly in industries that demand high performance. From aerospace to oil and gas, rubber seals are integral to the function of complex systems. However, when operating in extreme conditions—such as high temperatures, high pressures, and corrosive environments—standard seals will not suffice. Seal products used in these settings must be specifically engineered to withstand harsh conditions without compromising performance. Proper seal selection is critical for ensuring operational integrity and longevity.
This blog post explores how rubber seals behave under extreme environmental conditions and identifies the material and design choices that enhance their durability and functionality.
How Seals Perform in Extreme Environments
Extreme conditions impact seals in several critical ways, requiring careful consideration of both material composition and component design.
High-Temperature Exposure
Rubber seals can undergo significant changes when exposed to high heat. Traditional rubber compounds may soften, lose their elasticity, or experience chemical degradation when subjected to extremely high temperatures. These changes reduce sealing efficiency and heighten the risk of failure. In real-world applications, such as in an engine compartment or near industrial furnaces, rubber seals must resist long-term thermal exposure to avoid cracking, hardening, or becoming brittle over time.
The type of rubber selected greatly influences performance. For instance, fluoroelastomers and silicone rubbers maintain their elasticity and sealing capabilities even at higher temperatures. These materials are especially valuable in industries where thermal resilience is essential, such as the aerospace, automotive, and chemical processing industries. Conversely, seals made from natural or standard synthetic rubber can degrade quickly in similar conditions, leading to premature failure.
High-Pressure Conditions
Seals in high-pressure systems, such as hydraulic pumps or deep-sea drilling equipment, must be tough enough to resist deformation or rupture. Under intense pressure, poorly designed seals can compress excessively, leak, or even break apart.
Materials like polyurethane, PTFE (polytetrafluoroethylene), and specialized rubber blends are better suited for these environments because they exhibit excellent pressure resistance, enabling a tight seal without distortion. Designers can also adjust the seal’s structure by increasing its thickness or incorporating backup rings and other reinforcements to help it maintain shape and effectiveness under stress.
Chemical and Corrosive Environments
Corrosive fluids and aggressive chemicals pose another major challenge. In industries like chemical processing and pharmaceuticals, seals come into direct contact with solvents, acids, and oxidizers that can erode or chemically alter the material. To combat this, seals must be chemically inert and non-reactive. Engineered rubber compounds and ethylene propylene diene monomer (EPDM) are often used for their excellent chemical resistance, which helps prevent contamination and product loss in addition to withstanding corrosion.
Key Features of High-Performance Seals
How well a seal performs in an extreme environment depends on its design and material composition. High-performance seals are developed with several essential features in mind:
Chemical resistance. When exposed to harsh environments, seals must resist a broad range of chemicals to protect sensitive equipment and prevent dangerous leaks or material degradation. This is especially important in environments dealing with acids, solvents, or hydrocarbons.
Reduced friction and wear. Lower friction levels prevent excessive wear on the seal and its adjoining equipment. This prolongs the operational life of components and minimizes maintenance requirements and costs.
Superior leak resistance. A leak-proof design is critical for seals placed in pressurized or hazardous environments. High-quality seals form tight barriers that prevent fluid escape, supporting both process integrity and environmental compliance.
Versatility across applications. A wide range of seal types can be designed to meet an application’s specific requirements, from cryogenic temperatures to ultra-high pressures or corrosive process fluids. This versatility makes them a reliable choice for various sectors, including oil and gas, food processing, pharmaceuticals, and aerospace.
Contact the Experts at Pneu-Draulics
For over 40 years, Pneu-Draulics has been a trusted global supplier of high-performance sealing solutions for both OEM and MRO markets. As an ISO 9001:2015 certified company, we are committed to delivering seals that meet the strictest dimensional, material, and customer specifications. Our expertise in design consultation and product engineering ensures you receive the right components for your unique environment.
Our capabilities are backed by our quality certifications and government contracting codes:
ISO 9001:2015
CAGE Code: 8V217
UEI Number: NZLPJ3WBMDA8
NAICS Codes: 339991, 541330, 326291, 326299
Whether you need custom-engineered o-rings or expert recommendations, our technical specialists are here to help. Contact us to speak with an experienced team member, or request a quote to get started on your project.
Seals play a critical role in various industries, ensuring that fluids, gases, and other substances remain contained within systems and equipment. When they perform correctly, they prevent contamination and protect critical components. However, seal failures can lead to costly downtime, create serious safety hazards, and cause environmental concerns.
Understanding the root cause of a failure is the first step toward implementing an effective and lasting solution. This troubleshooting guide explores the most common types of seal failures to help you identify and resolve these issues.
Common Seal Failures
The following are some of the most frequent causes of seal failure in industrial applications.
Improper Installation
Improper installation is one of the most common sources of seal failure. Using the correct tools and procedures is critical to prevent seals from being damaged or installed in the wrong direction, both of which can lead to leakage. While careful training can mitigate many installation errors, another option is to redesign the housing. This is sometimes referred to as poka-yoke, a Japanese term for a mechanism that helps operators avoid mistakes.
Wear
While seals can wear over time, premature wear is often caused by contamination. Contaminants may originate from outside the system or be generated internally by moving parts like gears and pumps. Specialized seals can be used to exclude these contaminants, but if seals are breaking down faster than expected, you may also consider changing your hydraulic fluids. Additionally, higher-quality bearings will be less prone to deformation under load, which reduces the metal-to-metal contact that generates harmful particles.
Extrusion
In high-pressure applications, parts of a seal can break off and flow into the small gaps between hardware components. You can mitigate the risk of extrusion by incorporating backup rings, which provide additional support, or by switching from a standard elastomer seal to a more durable thermoplastic one. Redesigning the mechanism to minimize the clearance gaps between moving parts is another effective long-term solution.
Compression Set
Leakage that occurs at low pressure is often a sign that a seal has lost its elasticity, a phenomenon referred to as compression set. Rubber and polymer seals are particularly susceptible to this issue, as their performance depends on their ability to rebound and maintain pressure. Implementing a more frequent preventive maintenance schedule for seal replacement or switching to a material that is less susceptible to compression set over time can resolve this issue.
Pressure Trapping
If two seals are positioned next to each other, they should not seal in the same direction. When this occurs, fluid can become trapped between the seals, with fluid pressure building until it bursts through the weaker seal and causes a failure. To prevent this issue, we recommend utilizing a back-pumping design. A back-pumping design will allow the trapped fluid to be pumped back into the pressurized side of the system and relieve the pressure buildup.
Spiral Failure
This issue is more common with O-rings used in systems with long, fast strokes. This motion can cause an O-ring to twist within its groove and develop a series of spiral cuts across its surface. Consider switching to a different seal geometry, such as a square ring or X-ring, or using a more robust polymeric material that resists twisting to fix spiral failure.
Chemical Incompatibility
As companies switch to new hydraulic fluids to improve fire resistance or environmental safety, failures due to chemical incompatibility have become more common. Existing seal compounds may not be compatible with newer biodegradable or fire-resistant fluids, especially at certain temperatures. It is often necessary to change seal materials when changing fluids to ensure the seal life is not compromised.
Contact the Experts at Pneu-Draulics
For over 40 years, Pneu-Draulics, Inc. has been a trusted global supplier for the OEM and MRO markets, specializing in high-performance sealing solutions. Our ongoing commitment to quality is confirmed by our ISO 9001:2015 and other certifications (such as CAGE 8V217 and NAICS 339991, 541330, and 326291). We provide expert design consultation and a vast inventory of reliable seal equipment, including O-rings, U-cups, rod seals, and lubricants to meet your needs.
Liquid injection molding (LIM) creates precise, high-performance parts from liquid silicone rubber (LSR). Incorporating process automation, LIM injects a two-part compound of liquid silicone into the cavity of a heated mold, where the material quickly cures in the shape of the mold cavity.
Compared to conventional molding methods, LIM achieves consistent, superior quality and precision while producing less waste for products like custom-molded hydraulic seals. Durable liquid injection molding seals are ideal for hydraulic systems as they will perform better and more reliably than alternatives produced through compression or transfer molding.
At Pneu-Draulics, Inc., we pride ourselves on offering some of the most dependable hydraulic sealing solutions on the market today. Read on to learn more about the benefits of LIM seals and how the experts at Pneu-Draulics can support your operation.
Why Use LIM in Seal Manufacturing?
LIM is an adaptable production technique that’s compatible with multiple silicone durometers and can create tight-tolerance seals with precision, even for those with complex designs. It offers many benefits over traditional molding processes, enhancing efficiency through shorter cycle times.
Key Advantages of LIM
LIM lends seals an array of distinct advantages, such as:
Better durability under pressure. Liquid injection molding seals are a great option for hydraulic applications because they provide exceptional compression set resistance, and high-pressure operating conditions won’t negatively impact their integrity.
Consistency in complex geometries. As a low-viscosity material, LSR easily flows into intricately designed seal molds during the LIM process. This not only enhances seal uniformity but also minimizes the potential for defects regardless of the complexity of a seal’s geometry.
Faster production and lower scrap rates. As an automated production method offering shorter production cycles and fast part-curing times, LIM enables higher throughput and lower costs and scrap waste.
LIM vs. Traditional Molding Methods
LIM’s distinctive advantages make it the proper technique for many projects over more traditional methods like compression and transfer molding.
Compression Molding
Compression molding is sufficient for creating products with simplistic designs. The process inserts a pre-measured amount of LSR into the cavity of a heated, two-part mold. Upon closing the mold, the material will cure to form the desired shape. Cycle times for this technique are longer than those of LIM, however, and the process may increase scrap waste generation.
Transfer Molding
Forcing your material into a closed mold cavity utilizing a plunger, transfer molding achieves greater dimensional control compared to the compression molding process. That said, this technique still can’t reach the level of precision you can attain when using the LIM method.
Applications Across Key Industries
LIM is useful for a broad range of applications, such as:
Aerospace and defense. LIM seals are a good choice for mission-critical systems in aerospace and defense applications because of their supreme reliability. They’re capable of withstanding various environmental conditions through properties like LSR’s high thermal stability.
Heavy equipment and mining. Machinery and systems for the heavy equipment and mining sectors rely on rugged components that can handle the harsh environmental conditions to which they’ll be exposed. Resilient, durable LIM seals are up to the task.
MRO and aftermarket repair. LIM-made seals are ideal for maintenance, repair, and overhaul (MRO) projects for their consistent quality as well as their ability to minimize downtime and required maintenance. In turn, this leads to lower costs.
Final Thoughts on Using LIM Seals
Many engineers choose LIM over conventional molding methods because it reliably generates durable, high-quality liquid injection molding seals with uniform precision. LIM provides an efficient production solution while still delivering the versatility necessary to handle diverse hydraulic seal designs with applications across myriad industries.
Partner With a Trusted LIM Seal Supplier
When you partner with the Pneu-Draulics team as your LIM seal supplier, you’ll benefit from our extensive experience, multi-industry expertise, dependable supply chains, and a commitment to quality assurance that’s second to none. Contact us today to learn more about our LIM seal offerings and how custom-molded hydraulic seals from Pneu-Draulics can meet the specific needs of your next project.
HNBR is a highly saturated elastomer produced by special hydrogenation of nitrile butadiene rubber (NBR). Since its creation in the 1930’s, the petroleum-based synthetic rubber, NBR has long been the standard for general purpose, low cost and low heat applications while FKM (fluorcarbon)has been the choice for higher heat.
In the 1980’s, HNBR was introduced as an alternative between NBR and FKM (fluorcarbon). While NBR is inexpensive, it only has a temp range of -30°F to +250°F. FKM has a higher temp range,15°F to +400°F, but it can be cost prohibitive. HNBR offers a compromise between the two with a temp range of -20°F to +302°F. It also offers a higher tensile strength, higher operating temperatures, and excellent resistance to chemicals and ozone. Since its development, HNBR has been polymer of choice in air conditioning systems and many other sealing applications.
Before choosing which compound may work best for your application, don’t forget the role that the fluid, operating temperature,and pressure play in a healthy operating environment. We’ve made a list of the pro’s and con’s of HNBR below.
HNBR Advantages
Wide Temperature range
Abrasion resistance
Resistance to weather, ozone, fuels, oils, sour gas, steam, fats, automotive fluids, and extended service life
Typically green in color or easy identification
Available in both o-rings or various hydraulic cylinder packings
HNBR Disadvantages
Higher Cost
Limited resistance to aromatic oils and polar organic solvents
Poor electrical properities and poor flame resistance
Custom machined seals are a great sealing option when product isn’t available, cylinders have been modified, or when prototypes are needed, (without the expense and leadtime of tooling). There hundreds of profiles and materials available, made on demand with some lead times as quick as the next day.
Our sales staff will work with you to determine the profiles and materials best suited for your application. We will also work with our partners to engineer new sealing solutions. We’ve added a quick custom seal form to help you with your specialty seal selection. Just remember, when dealing with custom seals, S.T.A.M.P.S.S.
S-Size of current housing, groove dimensions
T-Temperature (operating) of system
A-Application where the system is to be used
M-Media/fluid to be sealed
P-Pressure
S-Speed system cycles
S-Surface finish of rod and/or bore
Rubber seals play a crucial role in various industries, providing effective sealing solutions for applications ranging from automotive and aerospace to construction and manufacturing. As sealing technologies continue to advance, the future of rubber seals holds several exciting trends and advancements and Pneu-Draulics will be there every step of the way.
Below are some key areas:
The rise of the Internet of Things (IoT) and smart manufacturing has opened doors for intelligent rubber seals. These seals can incorporate sensors and actuators to monitor and control parameters like pressure, temperature, and wear. Smart seals enable real-time monitoring, predictive maintenance, and improved efficiency by providing data-driven insights into seal performance and potential failures.
Self-healing materials are gaining attention in the field of rubber seals. Researchers are exploring the integration of microcapsules or reversible bonds within the seal material to enable automatic repair of small cracks or damages. Self-healing seals have the potential to significantly increase the lifespan and reliability of seals in demanding environments.
Sustainability is a growing concern, and the future of rubber seals includes a focus on eco-friendly alternatives. Manufacturers are exploring bio-based rubber seal materials derived from renewable sources. Additionally, recycling and waste reduction efforts are being implemented to minimize the environmental impact of seal production and disposal.
The adoption of additive manufacturing, particularly 3D printing, is revolutionizing the production of rubber seals. This technology allows for complex geometries and customization, reducing lead times and costs. 3D printing enables the creation of seals with optimized designs, tailored to specific applications, resulting in improved sealing performance.
Computer-aided design (CAD) and simulation tools are becoming increasingly sophisticated, enabling engineers to optimize seal designs for better performance. Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) simulations help predict seal behavior, improve sealing efficiency, and reduce leakage. Virtual prototyping and testing reduce the need for physical iterations, saving time and resources.
Surface treatments and coatings are being developed to enhance the performance of rubber seals. These technologies aim to improve properties such as friction, wear resistance, and chemical resistance. Nano-coatings and low-friction surface modifications are being explored to minimize seal friction and extend service life.
Industries such as oil and gas, aerospace, and high-performance automotive applications require seals that can withstand extreme conditions. Future advancements will focus on developing seals capable of withstanding high temperatures, high pressures, corrosive environments, and harsh chemicals, ensuring optimal performance and safety in demanding applications.
The future of rubber seals holds great potential for advancements that will enhance their performance, durability, and sustainability. These innovations will contribute to increased efficiency, reduced maintenance costs, and improved reliability in various industries, supporting technological progress and addressing evolving challenges.
O-rings are essential components used for sealing applications in various industries. Understanding key terminology related to durometer and Shore hardness is crucial when selecting the correct O-ring material. In this article, we will delve into the meaning of these terms and their significance in relation to FKM (fluorocarbon rubber), urethane, and NBR (nitrile butadiene rubber) materials.
Durometer is a measure of the hardness of an elastomer material, such as rubber. Shore hardness is the most commonly used durometer scale, developed by Albert F. Shore. It quantifies the hardness by measuring the resistance to indentation. The Shore hardness scale consists of different scales, including Shore A, Shore B, and Shore D.
Shore A durometer measures the hardness of relatively soft elastomers, particularly rubber materials. It has a scale ranging from 0 to 100, where higher values indicate a harder material. O-rings made from materials like NBR are typically measured using Shore A durometer. For instance, a Shore A durometer reading of 70 indicates a relatively hard material.
Shore B durometer is used to measure the hardness of elastomers that are slightly harder than those measured with Shore A durometer. It also has a scale from 0 to 100, with higher values representing increased hardness. However, Shore B durometer is less commonly used for O-rings, as materials like FKM and NBR generally fall within the Shore A measurement range.
Shore D durometer measures the hardness of rigid materials, including hard rubbers, plastics, and thermoplastic elastomers. It has a scale ranging from 0 to 100, where higher values indicate greater hardness. Although Shore D durometer is not typically used for O-rings, it can be relevant when evaluating materials like urethane, which can have higher hardness compared to traditional elastomers.
Understanding durometer and Shore hardness scales is crucial when selecting the right O-ring material for specific applications. Shore A durometer is commonly used for measuring the hardness of FKM and NBR O-rings, while Shore B and Shore D durometers are more relevant for harder materials like urethane. By considering the appropriate hardness for each material, businesses can ensure the selection of O-rings that offer optimal sealing performance, durability, and resistance to specific operating conditions.
Per- and polyfluoroalkyl substances (PFAs) are an ever-present part of our lives, from our cookware to our clothing and, notably, the sealing industry. However, these man-made chemicals have been the focus of increasing scrutiny. What is the future of PFAs and how will it shape the sealing industry?
PFAs are synthetic chemicals known for their ability to resist heat, water, and oil. This has made them incredibly useful in various industries, including the manufacture of gaskets, seals, and O-rings.
However, PFAs have been labeled “forever chemicals” due to their persistence in the environment and in our bodies, leading to potential health risks. As more research uncovers these impacts, the future of PFAs looks increasingly uncertain.
In the past, the sealing industry has been a significant user of PFAs due to their unique properties. PFAs provide exceptional performance in high-temperature applications and in environments exposed to aggressive chemicals. But with potential regulatory changes on the horizon, the industry is faced with an impending challenge. How do we maintain high-performance sealing solutions without relying on PFAs?
A possible alternative is the use of perfluoroelastomers (FFKMs), which maintain many of the desirable properties of PFAs but have a different chemical structure that may pose less environmental and health risk.
The development of greener manufacturing processes and materials also holds promise for creating PFAs-free seals and gaskets. These new materials must meet the rigorous demands of the industries served, a challenge that the sealing industry is determined to meet.
The future of PFAs presents a complex challenge for the sealing industry. However, as regulatory pressures mount, the industry is showing it’s ready to innovate, seeking out alternatives that deliver the same high performance without the environmental and health impact. This is an exciting time in the industry, a time of change and innovation. The sealing industry may soon unveil new materials that revolutionize the way we think about high-performance seals.
Sources:
Per- and Polyfluoroalkyl Substances and Your Health
Sealing Technology, “The Impact of PFAs on Sealing”
Revolutionizing High-Temperature Stability and Chemical Resistance
In today’s fast-paced and demanding industrial landscape, engineers and manufacturers are constantly seeking advanced materials that can withstand extreme conditions while delivering reliable performance. Parker Hannifin has introduced their newest FFKM compound FF156, which offers exceptional high-temperature stability and broad chemical resistance. The remarkable features and applications of Parker’s FF156 compound shows its value and why it will become the preferred choice of engineers in critical environment industries.
One of the standout features of compound FF156 is its extraordinary high-temperature stability. Capable of withstanding temperatures of up to 527°F/275°C, FF156 ensures reliable sealing even in the most demanding applications. This exceptional heat resistance makes it suitable for use in environments such as high-temperature reactors, downhole drilling systems, exhaust and turbo systems, and steam applications. Engineers can have peace of mind knowing that their equipment can operate efficiently at elevated temperatures without compromising on sealing integrity.
In addition to its impressive high-temperature capabilities, FF156 also boasts broad chemical resistance. It exhibits exceptional resistance to aggressive media, including acids, amines, hot water, ketones, aldehydes, esters, ethers, aromatics, and many more. This versatility enables FF156 to thrive in chemically demanding environments, making it ideal for applications in the chemical processing, oil and gas, and pharmaceutical industries. Furthermore, FF156 has received USP Class VI approval, ensuring its compliance with the strict regulatory standards required in medical and pharmaceutical applications.
FF156 FFKM is available in a range of geometries, including O-rings, molded shapes, extruded profiles, and spliced configurations. This versatility allows engineers to choose the most suitable form for their specific application requirements. Whether it’s mechanical seals, pumps, valves, instrumentation equipment, high purity filters, or any other critical component, FF156 delivers outstanding sealing performance across various industries.
Parker Hannifin’s O-Ring and Engineered Seals Division has gained the reputation of being the preferred choice of engineers in critical environment industries. Aerospace, oil and gas, and chemical processing are just a few of the sectors that rely on Parker’s expertise and products to ensure the safe and reliable operation of their equipment.
You can trust Pneu-Draulics with our extensive experience, commitment to innovation, and exceptional customer support, to guide you every step of the way when determining the best material and profile for your application.
When it comes to rubber and urethane seals, understanding their shelf life is essential to ensure optimal performance and reliability. Seals are commonly used in various industries, including automotive, manufacturing, and engineering. Knowing how long these seals can be stored before their properties begin to degrade is crucial for maintaining their effectiveness.
Understanding Rubber Seals
Rubber seals, commonly made from materials such as neoprene, nitrile, or silicone, are widely used for their flexibility, resistance to temperature extremes, and durability. However, rubber seals are not invincible and can deteriorate over time when not stored or used correctly.
The shelf life of rubber seals can vary depending on several factors.
Rubber seals should be stored in a cool, dry environment away from direct sunlight, chemicals, ozone, and extreme temperatures. Exposure to these elements can accelerate the aging process and lead to premature deterioration.
Different types of rubber have varying resistance to environmental factors. It’s important to consult the manufacturer’s guidelines to determine the expected shelf life of a specific rubber seal material.
The quality and formulation of the rubber material used in the seals can impact their overall shelf life. Higher-quality seals are often designed to last longer and maintain their properties for an extended period.
Understanding Urethane Seals
Urethane seals, also known as polyurethane seals, are valued for their excellent wear resistance, high load-bearing capabilities, and resistance to oil and solvents. They are commonly used in hydraulic systems, pneumatic applications, and heavy machinery.
The shelf life of urethane seals can also be influenced by various factors:
Similar to rubber seals, urethane seals should be stored in a controlled environment with low humidity and moderate temperatures. Exposure to excessive moisture and heat can degrade their properties.
The formulation of the urethane material, including additives and fillers, can affect its resistance to environmental factors and determine its expected shelf life.
It is crucial to follow the manufacturer’s guidelines for the storage and handling of urethane seals. They may provide specific instructions or recommendations for prolonging the shelf life of their products.
Inspecting and Replacing Seals
Regardless of the type of seal, it’s important to regularly inspect them for signs of deterioration or damage, even if they are within their expected shelf life. Common indicators of seal degradation include cracks, hardening, swelling, or a loss of elasticity. If any of these signs are present, it is advisable to replace the seals to prevent potential failures and maintain system integrity.
The shelf life of rubber and urethane seals can vary depending on storage conditions, seal type, and material quality. Proper storage in controlled environments and adherence to manufacturer’s recommendations are essential for prolonging the lifespan of these seals. Regular inspections and proactive replacement when signs of degradation are detected will help ensure the optimal performance and reliability of the seals in various industrial applications.
