Low-Temperature Sealing: O-Rings and Materials for Cryogenic and Arctic Applications
Updated: Aug 25, 2025
From LNG valves and cryogenic pumps to arctic wellheads, satellites, and vacuum instruments, low-temperature environments present a unique set of challenges for elastomer seals. As temperatures fall, many common rubber compounds approach their glass transition region: the polymer chains lose mobility, the material stiffens, and resilience (the ability to spring back and maintain contact pressure) drops sharply. The result is a higher risk of startup leakage, brittle cracking, spiral failure, and accelerated wear—especially when systems cycle between hot and cold.
This guide explains why sealing gets harder as temperature drops, compares the best O-ring materials for cryogenic and arctic duty, and outlines design and maintenance tactics that keep systems sealed. It includes links to Canyon Components’ product and reference pages for quick specification, including:
- Low-Temperature Elastomers & O-Rings
- Combining Low-Temperature and AED FKM Viton™ for Extreme Oil & Gas
- Low-Temperature PVMQ Silicone
- Low-Temperature Viton™ (FKM)
Why low temperatures cause seals to fail
Low temperatures affect elastomers in multiple ways—and these effects stack up:
- Brittleness and loss of elasticity
Near the glass transition, elastomers stiffen and cannot rebound after compression. Contact stress plummets, especially at startup, and micro-leak paths open. Depending on the material, a seal that was tight at ambient can seep or whistle at subzero temperatures, or cryogenic conditions. - Thermal contraction and differential shrinkage
Metals and elastomers contract at different rates. If the O-ring shrinks more (or the hardware expands less), squeeze can fall out of spec. With insufficient squeeze, the O-ring may not seal, especially under low pressure. - Lubrication challenges
Many lubricants thicken or solidify at low temperature, increasing startup friction. Higher friction encourages spiral failure in reciprocating service if groove design and material choice aren’t optimized. - Increased risk of explosive decompression in gas service
Rapid decompression of absorbed gas can cause subsurface rupture (RGD/AED failure), and the risk can be worse when seals are brittle. Balancing low-temperature flexibility with AED resistance is key in oil & gas duty (see: Combining Low-Temperature and AED FKM Viton™). - Outgassing in vacuum/cryogenic
In ultra-clean systems, even minute outgassing at cryogenic temperatures can contaminate optics or sensors. Materials chosen for low-temperature resilience should also be compatible with vacuum cleanliness goals.
What to ask before you select a low-temperature seal
Gather this data first—then match to materials below:
- Lowest continuous and startup temperatures, plus low temp duration
- Thermal cycling profile (frequency, ramp rate, dwell times)
- Media (e.g., LNG, liquid oxygen, CO₂, H₂, vacuum, water/glycol) and purity requirements
- Motion (static, slow reciprocating, high-frequency oscillation, rotary, etc.) and pressure (steady vs pulsing)
- Compliance (e.g., FDA/USP for sanitary, AED/NORSOK for oil & gas, cleanliness for vacuum)
- Maintenance plan (inspection intervals, expected replacements at seasonal or cycle-count triggers)
Use this with Canyon’s selection pages for a faster, higher-confidence choice:
Material deep-dive: elastomers that work in the cold
1) Silicone (VMQ, PVMQ) — the low-temp flexibility champion
Why it works: Silicone’s backbone retains flexibility far below freezing, maintaining resilience and conformability when many elastomers are glassy.
- Best for: Static sealing at sub-zero temperatures, sanitary and medical systems with steam sterilization cycles, aerospace interiors and environmental control, optics/electronics exposed to cold.
- Weaknesses: Standard VMQ can exhibit higher compression set under heat, reduced tear strength, and poor fuel/oil resistance. For ultra-cold applications, consider PVMQ formulations engineered for improved glass-transition behavior (see: Low-Temperature PVMQ Silicone).
- Notes: Many silicones are available in FDA and USP Class VI grades—useful for cryogenic or refrigerated sanitary duty.
2) Fluorosilicone (FVMQ) — silicone flexibility with fuel resistance
Why it works: Adds fluorination to the silicone backbone, improving resistance to fuels and solvents while maintaining low-temperature performance.
- Best for: Aerospace fuel systems exposed to long periods of low temperatures, under-hood components with both fuel splash and winter starts, environments combining hydrocarbon exposure and sub-zero temperatures.
- Weaknesses: Upper temperature and hot-air performance trail VMQ; compression set at heat can be higher than FKM.
3) FKM (Viton™) low-temperature grades — GLT and GFLT families
Why it works: Standard FKM can stiffen in deep cold, but low-temperature FKM variants shift the glass-transition lower while preserving FKM’s strength and chemical resistance. In the Viton™ families, these are commonly referred to as Viton™ GLT (FKM GLT) and Viton™ GFLT (FKM GFLT) grade types.
- Best for: Oil & gas, aerospace, and industrial systems requiring both fuel/chemical resistance and sub-zero starts. Ideal where silicone’s tear strength is insufficient or where hydrocarbon compatibility rules out VMQ/FVMQ.
- Explore options: See Canyon’s Low-Temperature Viton™ (FKM) overview for real-world use cases and temperature capabilities.
- AED angle: For high-pressure gas, choose low-temp FKM that is also AED-rated (see: Combining Low-Temperature and AED FKM Viton™).
4) FFKM (Perfluoroelastomer) — the ultra-pure, low-temp specialty
Why it works: Some FFKM grades are formulated for excellent chemical resistance with enhanced low-temperature flexibility, making them valuable in cryogenic, ultra-clean, or plasma/vacuum environments.
- Best for: Semiconductor vacuum tools, cryogenic valves where purity is paramount, aggressive clean chemistries at sub-zero temperature.
- Explore: Canyon’s perfluoroelastomer portfolio spans CanRez®, Kalrez®, and Chemraz®—choose per application:
5) EPDM — cost-effective in water-based, low-pressure environments
Why it works: EPDM offers good cold-flexibility in water, steam, and glycol systems with low hydrocarbon exposure.
- Best for: HVAC and water handling in cold climates, sanitary systems (with FDA/NSF options), outdoor gaskets and enclosures.
- Weaknesses: Poor fuel/oil resistance; not suitable for hydrocarbon service.
6) Polyurethane (TPU/PU) — abrasion-resistant, cold-capable workhorse
Why it works: Polyurethane maintains toughness and wear resistance in moderate sub-zero conditions.
- Best for: Pneumatics and hydraulics with reciprocating motion; wipers, backup rings, and custom seals requiring high tear/abrasion resistance at low temp.
- Weaknesses: Chemical compatibility varies; verify against fuels/solvents.
Tip: A hybrid strategy often performs best—e.g., low-temperature FKM for media resistance plus PU or PTFE backup for dynamic durability, or silicone for static cryo with PTFE backup where extrusion could occur.
When elastomers are not enough: spring-energized and PTFE-based seals
Deep cryogenic and vacuum applications often demand near-zero outgassing, minimal compression set, and stable contact force across severe thermal swings. In these cases:
- Consider spring-energized seals with PTFE or other low-temperature jackets. The internal spring compensates for thermal contraction and material stiffness, maintaining sealing force during long periods of low temperature and warm starts.
- Explore Canyon’s options here: Spring-Energized Seals.
Where they shine:
- Cryogenic pumps and valves (LNG, LOX, LN₂)
- Space/aerospace vacuum systems and thermal-vac chambers
- Ultra-clean semiconductor tools where outgassing and particle generation must be minimized
Failure modes unique to the cold—and how to prevent them
1) Startup leakage
- Mechanism: At the first cold start, the O-ring may be too stiff to energize, leaving micro-gaps.
- Mitigation: Select VMQ/PVMQ, FVMQ, or low-temp FKM (GLT/GFLT-type); increase squeeze slightly (within design limits); add a light, compatible lubricant that stays mobile at the minimum temperature.
2) Spiral failure in reciprocating motion
- Mechanism: Higher friction + stiff seal = twisting/spiraling in the groove.
- Mitigation: Use X-rings in place of round O-rings where possible; optimize groove dimensions; use lubricants that remain fluid at low temperature; consider polyurethane for wipers/energizers; control stroke speed at cold start.
- Mechanism: Handling or installation at sub-zero temperatures can nick or crack a cold, glassy elastomer.
- Mitigation: Warm parts before installation when possible; chamfer edges; use install tools; avoid overstretching; use VMQ/PVMQ or low-temp FKM.
4) Compression set after thermal cycling
- Mechanism: Repeated hot-cold cycles can relax the network and change squeeze.
- Mitigation: Choose low-set materials; verify gland fill across the full thermal range; plan preventive replacements after a defined number of cycles.
5) AED/RGD (explosive decompression) in cold, high-pressure gas
- Mechanism: Absorbed gas ruptures the seal upon rapid venting; brittle seals are easier to crack.
- Mitigation: Use low-temperature AED-rated FKM and control decompression rate; see Canyon’s guidance: Combining Low-Temperature and AED FKM Viton™.
Low-temperature design tactics (that make a big difference)
- Choose the right cross-section
Thicker cross-sections hold more stored energy—but also shrink more with temperature and may relax slowly. Balance cross-section with the allowable gland fill and expected contraction. - Account for thermal contraction
Calculate squeeze at both ambient and minimum temperatures. Ensure the seal remains in the recommended squeeze window across the full range. - Mind groove geometry for dynamic seals
For reciprocating applications, a stable groove is crucial. Avoid overly wide grooves that permit rolling. Consider X-rings for inherent anti-spiral stability. - Add backup rings where pressure is present
As temperature falls, modulus increases, but during warm-up the seal can soften quickly—risking extrusion if pressure spikes. PTFE or PU backups help maintain integrity through the transition. - Use low-temperature lubricants
Select a compatible lubricant whose viscosity remains low at the minimum temperature; this reduces startup friction and spiral risk. - Bake-out/cleanliness for vacuum/cryogenic
Pre-bake seals to reduce outgassing. Keep parts clean, dry, and bagged to prevent moisture uptake and surface contamination. - Validate via relevant tests
- TR-10 (temperature retraction) and brittle point tests are useful performance indicators.
- Cryogenic pressure-leak tests and thermal cycling prove real-world reliability.
Quick comparison table (scan & shortlist)
| Material | Low-temperature behavior | Chemical/fuel resistance | Dynamic suitability | Notes/Links |
|---|---|---|---|---|
| Silicone (VMQ/PVMQ) | Excellent flexibility far below freezing (PVMQ offers enhanced cold start) | Moderate; avoid fuels/solvents | Static/slow dynamic | Low-Temp PVMQ |
| Fluorosilicone (FVMQ) | Very good at low temp | Improved fuels/solvents vs VMQ | Static/slow dynamic | Good for aerospace fuel systems |
| Low-Temp FKM (GLT/GFLT-type) | Strong sub-zero resilience compared to standard FKM | Excellent fuels/oils; good chemicals | Good dynamic strength | Low-Temp Viton™ |
| FFKM (select grades) | Good low-temp resilience in specialty grades | Exceptional chemicals | Static; dynamic depends on grade | CanRez, Kalrez, Chemraz |
| EPDM | Good in water/steam at sub-zero | Poor fuels/oils | Static | Cost-effective for HVAC/water |
| Polyurethane (PU) | Good toughness at cold temps | Varies by chemistry | Excellent dynamic | Great for wipers/backup |
(For an extended material list and operating ranges, see: Low-Temperature Elastomers & O-Rings.)
Industry snapshots & use-case tips
Oil & Gas (Arctic completions, topside, and subsea)
- Combine low-temperature FKM (GLT/GFLT-type) with AED resistance for high-pressure gas service.
- Add backup rings; manage decompression ramp rates.
- Reference: Low-Temperature Elastomers and Combining Low-Temp and AED FKM.
LNG/Cryogenic Valves and Pumps
- Consider spring-energized PTFE jackets for deep cryogenic duty with VMQ or FFKM used elsewhere in the assembly.
- Pre-bake for low outgassing; maintain clean assembly practices.
- See: Spring-Energized Seals.
- For cold-soaked fuel systems, FVMQ or low-temp FKM provide the necessary balance between cold flexibility and fuel resistance.
- For cabin/interior environmental seals, VMQ/PVMQ may be preferred for wide thermal span and flame/smoke/tox compliance (verify grades).
Semiconductor & Vacuum Systems
- Use low-outgassing FFKM or spring-energized PTFE in cryo/vacuum tools; pre-bake parts and verify cleanliness specs.
- Ensure cryo-to-ambient cycles don’t exceed gland design allowances.
- VMQ/PVMQ and FFKM are common choices when both sterilization (steam or chemical) and low temp matter.
- Validate with USP Class VI or FDA requirements as applicable.
Practical selection playbook
- Define the real minimum
Is −40 °C the minimum during long periods of low temperature, or do you see −55 °C, −60 °C in short bursts, or cryogenic exposure? The right answer determines whether VMQ/PVMQ or low-temp FKM (GLT/GFLT-type) is the baseline, or if you should move to FFKM or spring-energized PTFE. - Balance media and motion
If fuels or aromatic solvents are present, FVMQ or low-temp FKM outclass standard silicone. For high-cycle reciprocating motion, polyurethane wipers and backup rings can protect the primary seal. - Engineer the hardware
Use Canyon’s guidance on groove dimensions and squeeze for cold service. Verify gland fill, diametral clearance, and surface finish across the thermal envelope. - Don’t forget AED
In high-pressure gas service, choose low-temperature FKM that’s AED-rated (and manage decompression rates). Start with: Combining Low-Temp and AED FKM Viton™. - Plan maintenance around cycles
Thermal cycling counts. Replace seals before the inflection point where compression set and brittleness converge.
Canyon Components low-temperature portfolio and support
Canyon Components supplies a broad, application-driven selection of low-temperature materials and sealing systems, including:
- Low-Temperature Silicone (VMQ/PVMQ) for extreme flexibility: Low-Temperature PVMQ Silicone
- Low-Temperature FKM (Viton™ GLT/GFLT-type) for fuel/chemical resistance below freezing: Low-Temperature Viton™
- Perfluoroelastomers (FFKM) for ultra-clean, chemically aggressive, cold environments:
- Spring-Energized PTFE solutions for the deepest cryogenic and vacuum duty: Spring-Energized Seals
- A comprehensive primer with material lists and ranges: Low-Temperature Elastomers & O-Rings
Our engineering team can help map your temperature and cycling envelope, translate media lists into compatibility-driven material shortlists, and tune groove design for cold-start resilience. If you’re balancing low-temperature and AED requirements for gas service, we may recommend FKM GLT/GFLT-type formulations with appropriate AED validation, or hybrid designs using backups and vented cavities to protect seals during decompression.
Final takeaways
- Low temperatures reduce elastomer resilience, increase brittleness, and can dramatically lower contact stress at startup.
- VMQ/PVMQ delivers best-in-class cold flexibility for static duty; FVMQ adds fuel resistance; low-temp FKM (GLT/GFLT-type) brings low-temperature performance with superior chemical strength; FFKM and spring-energized PTFE serve the most extreme, high-purity cryo/vacuum applications.
- Success comes from material + design + operating practice: validate squeeze at min temp, control startup friction and decompression, and plan replacement by cycle count, not just calendar time.
Ready to spec a seal for sub-zero or cryogenic service? Start with Canyon’s material guides and connect with engineering to finalize the lowest-risk, longest-life solution for your duty cycle.
