Low-Temperature O Rings
Low-Temperature O Rings – Manufactured From Approved Materials
For more than 50 years, M Barnwell Services has provided Low-Temperature O Rings to top Energy, Compressor Pump, and Valve, Chemical Processing, and Semiconductor companies worldwide. As one of the UK’s biggest independent fluid seal stockists and distributors, our customers can trust that they’ll receive the right product for their needs.
Our proficient team manages the entire production process, from prototyping and testing to final part manufacturing. Additionally, we offer specialised certification upon request.
If you would like more information about our range, download our catalogue, or contact a team member.
Low-Temperature O Ring Materials
It’s crucial to note that many elastomers offer alternative formulations to decrease their working temperature range. If a specific material is chosen for its chemical compatibility or mechanical attributes, there might be a low-temperature (LT) variant accessible. For temperatures below -25°C, the following materials are recommended: NBR, HNBR, VMQ, FVMQ, Kalrez®, PTFE, FEP Encapsulated O Rings, and Astra Seals®.
- Nitrile Low-Temperature (NBR LT)
– Temperature Range: -45°C to +110°C.
– Affordable, moderate resistance to oil, chemicals, and grease.
– Vulnerable to shrinking and reduced chemical resistance at low temperatures.
– Lowering acrylonitrile content in nitrile enhances low-temperature resistance. However, this adjustment affects fuel and oil resistance.
– Ideal for cost-effective sealing with moderate chemical exposure needs. - Hydrogenated Nitrile Low-Temperature (HNBR LT)
– Temperature Range: -50°C to +150°C.
– Enhanced chemical and oil resistance.
– Vulnerable to shrinking and reduced chemical resistance at low temperatures.
– Adjusting acrylonitrile content in hydrogenated nitrile (HNBR) impacts flexibility.
– HNBR outperforms NBR in mechanical properties, preventing extrusion and wear.
– Resistant to a broader array of oils, fuels, and chemicals.
– Notably resilient to aliphatic hydrocarbons, hydraulic fluids, and dilute acids.
– Unsuitable for chlorinated hydrocarbons, polar solvents, or strong acids. - Silicone (VMQ)
– Standard Temperature Range: -55°C to +200°C. Special LT Compound Temperature: -100°C to +220°C.
– Remarkable low-temperature resistance. Silicone excels at extreme temperature ranges, with a working limit down to -55°C. Special compounds extend this capacity to -100°C, 50°C below standard materials.
– Poor wear resistance and limited chemical compatibility.
– Resistant to animal and vegetable oils.
– Falls short in tear strength and wear resistance, unsuitable for dynamic uses.
– Susceptible to most acids, alkalis, hydrocarbon-based fuels, and petroleum oils. - Fluorosilicone (FVMQ)
– Fluorinated Temperature Range: -60°C to +200°C.
– A fluorinated version with -60°C working temperature.
– Offers some improvement in chemical resistance but is still limited against ketones, certain acids, brake fluids, and amines.
Universally Resistant Compounds
- Kalrez®
– Temperature Range: -42°C to +220°C.
– Exceptional chemical resistance across the board.
– For aggressive chemicals, FFKM is the most sought-after elastomeric material.
– Remarkable chemical resistance and elasticity. - PTFE
– Temperature Range: -200°C to +250°C.
– Remarkable low temperature and chemical resistance.
– Limited compression set, lacks memory.
– Remains unaffected by most acids, alkalis, and solvents.
– Low coefficient of friction grants a non-lubricated assembly due to its slippery surface.
– While durable and abrasion-resistant, PTFE’s minimal compression set makes it susceptible to denting, potentially compromising continuous pressure seals. - FEP Encapsulated O Rings
– Temperature Range: -60°C to +204°C.
– Versatile suitability for various working conditions. FEP encapsulated O Rings are adaptable to diverse environmental requirements.
– Leveraging PTFE’s exceptional chemical resistance, it envelops a standard O Ring as protection.
– This combination, with silicone inner O Ring, achieves low-temperature capability down to -60°C.
– Suitable for applications requiring FDA, USP CLASS VI, metal detectable, and semi-conductive properties. - Astra Seals®
– Temperature Range: -250°C to +204°C.
– Unmatched low-temperature compression set, no glass transition state.
– Suitable only for axial sealing without stretching.
– Optimal solution for extreme cold resistance, devoid of rubber.
– Consisting of a 302 stainless steel ribbon and an FEP encapsulated O Ring casing.
– Exceptional compression set and universal chemical compatibility.
– Preferred choice for applications like space shuttle rockets and astronomical needs.
Why Do Low-Temperature O Rings Fail?
When cooled, rubber loses its elasticity, impacting what’s called a ‘Compression Set‘ in elastomers. This measure assesses how well the elastomer bounces back to its original size after being compressed. A lower compression set means the material can better handle shifts in pressure (dynamic) and sustained strain (static), ensuring a dependable seal between the O Ring and its casing. However, in colder temperatures, the compression set can worsen, leading to seal leaks and O Ring failure.
To counteract this issue, a solution is to apply continuous pressure on the O Ring, known as ‘squeeze’. By setting a squeeze of 30% or more, it’s possible to mitigate O Ring failures in cold conditions. However, practicality dictates that dynamic applications shouldn’t exceed a squeeze of 16%, due to the constraints of friction and wear.
M Barnwell Services’ High-Temperature Seals:
- MBMS0493 Low-Temperature FFKM:
– Operates effectively in an expansive temperature range of -46°C to +250°C (-51°F to +482°F).
– Designed for top-tier chemical resistance, including acids and amines.
– Reduced susceptibility to swelling, ensuring prolonged performance in valves, pumps, and mechanical seals.
Numerous low-temperature seals are at your disposal. For details, contact our team or explore the FFKM O Ring/fluoroelastomer (FKM/Viton™) page.
Applications By Industry:
- Automotive
– Refrigeration systems for transport vehicles.
– Cold weather testing equipment.
– Air conditioning systems. - Aerospace and Defence
– Rocket fuel systems.
– Aircraft fuel tanks and lines.
– Spacecraft propulsion systems. - Oil and Gas
– Subsea equipment and connectors.
– Offshore drilling equipment.
– Arctic oil exploration equipment. - Chemical Processing
– Cryogenic distillation equipment.
– Low-temperature reactors.
– Chemical storage and transport containers.
– Liquid nitrogen systems. - Semiconductor
– Wafer processing.
– Vacuum systems.
– Cooling systems for chip testing. - Food and Beverage
– Industrial refrigeration systems.
– Cold storage facilities.
– Ice cream production equipment. - Pharmaceutical
– Ultra-cold storage containers for vaccines and drugs.
– Laboratory equipment for low-temperature research.
– Cryopreservation systems and cryosurgery devices.
– Blood storage systems.
– Cryogenic preservation of biological samples.
More Industry-Specific Extreme Seals
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As a reliable partner to global OEM manufacturers, M Barnwell Services ensures quality products and an exceptional service experience. With £5.1 million in sealing inventory and five UK branches strategically positioned, we’re primed to meet and surpass your needs.