BY MATERIAL
FLUID supplies custom FVMQ (fluorosilicone) O-rings for sealing applications involving low temperatures and selected fuels or oils. We support material selection and seal design based on your operating conditions and application requirements.
Initial response within 12 hours.
01 / FVMQ REQUIREMENTS
FVMQ is a fluorosilicone elastomer. Its silicone-based structure incorporates fluorinated groups that can improve resistance to selected fuels and mineral oils compared with conventional silicone rubber.
This makes FVMQ worth considering when a seal must remain flexible in cold conditions while contacting these fluids. It does not make FVMQ universally resistant to chemicals or suitable for every sealing arrangement.
FVMQ is not simply a blend of FKM and silicone. Its mechanical behaviour, fluid compatibility and sealing performance must be evaluated as a distinct material.
02 / FVMQ REQUIREMENTS
A seal may need to work immediately after cold storage or an overnight shutdown. FVMQ can be a candidate where cold flexibility and fuel compatibility are both important, provided the specific compound is suitable for the fuel and operating conditions.
Static seals exposed to selected lubricating oils may also benefit from a fluorosilicone evaluation. Confirm the oil formulation, additives, temperature and exposure duration rather than relying on the description “oil-resistant.”
If an existing silicone seal swells, softens or loses dimensional stability in a fuel or oil environment, FVMQ may be worth reviewing. These symptoms alone do not establish the cause, and changing materials does not remove the need to check the gland and operating conditions.
03 / FVMQ REQUIREMENTS
Compared with VMQ: FVMQ generally offers improved resistance to selected hydrocarbon fuels and mineral oils. VMQ may remain appropriate where its fluid compatibility and temperature behaviour meet the requirement. Do not assume their hot-air ageing performance is identical.
Compared with conventional FKM: FVMQ can offer a useful low-temperature selection direction. However, low-temperature FKM compounds are also available, and the decision must include fluid resistance, mechanical demands and seal design.
For any comparison: Evaluate the proposed compounds rather than selecting by material abbreviation alone. Similar hardness or a similar published temperature range does not establish equivalent sealing performance.
A practical selection approach: Consider FVMQ when low temperature and fuel exposure occur together, then check media compatibility, mechanical demands and the sealing arrangement. Include a suitable low-temperature FKM option in the comparison where relevant. Retain VMQ where its fluid compatibility and operating conditions are appropriate. FVMQ is not a universal upgrade over either material.
04 / FVMQ REQUIREMENTS
Review the minimum operating temperature, cold-start condition, normal temperature and short-term peaks together with exposure time and cycling frequency.
For fuel service, identify the fuel grade and any oxygenates, additives or blended components. For oil service, provide the oil specification and relevant additives. A test in one reference fuel or oil does not establish compatibility with every commercial fluid.
Cleaning chemicals also matter. Do not assume compatibility with ketones, phosphate-ester fluids or a brake fluid of unspecified composition. Each requires a separate material review.
External supplier technical documentation lists a specific FVMQ compound, nominally 70 Shore A, with a temperature-range reference down to −60°C. The same documentation records no cracking at −55°C in an ASTM D2137 brittleness test. These are different measures; no TR10 value is reported.
This is external supplier technical information, not a FLUID product test result or an independently verified third-party laboratory report. Neither figure establishes the minimum sealing temperature of a FLUID finished O-ring. Confirm the proposed compound, available evidence and actual sealing conditions.
05 / FVMQ REQUIREMENTS
Rubber stiffening, thermal contraction and reduced elastic recovery can affect sealing contact during a cold start. Review the initial squeeze, dimensional tolerances and pressure sequence, particularly where the seal must work before the equipment warms up.
Low-pressure operation also matters: the seal cannot rely on substantial system pressure to compensate for inadequate initial contact.
Compression set describes residual deformation after specified compression and recovery conditions. It is not a direct measurement of retained sealing force or service life.
Review temperature, exposure duration, fluid effects and previous compression history alongside the gland design.
Allow for dimensional tolerances, thermal expansion and possible fluid-induced volume change. Pressure, extrusion gaps and the material’s mechanical properties must be assessed together.
Increasing hardness alone does not establish a suitable high-pressure seal.
FVMQ O-rings are primarily considered for static sealing. Friction, abrasion resistance, tear resistance and mechanical strength can limit sliding applications.
Reciprocating or rotary service requires a separate assessment of motion, speed, contact surfaces, lubrication, pressure and wear. A compound suitable for a flexible diaphragm is not automatically suitable for a sliding O-ring seal.
Avoid sharp edges, excessive stretching and assembly damage. Any installation lubricant must also be compatible with the material and application.
For gas or vapor sealing, permeability requirements should also be reviewed. Good fuel compatibility does not automatically establish adequate resistance to gas permeation.
06 / FVMQ REQUIREMENTS
Selected static connections, housings and fuel-related components may warrant FVMQ evaluation. Confirm the actual fuel, cold-start conditions, pressure and relevant material specification.
Static seals in suitable connections, valves and equipment can be reviewed where fuel exposure and low temperatures occur together. Pressure cycling, leakage requirements and installation details remain important.
FVMQ may be considered for static seals exposed to compatible oils or fuels, including equipment that starts after cold storage.
Fluorosilicone is used in some aerospace fuel-sealing specifications. Any enquiry requires separate review of the specified material, traceability, documentation and applicable approvals. This application direction does not establish FLUID aerospace certification, qualification of a proposed compound or a completed customer application.
These are application directions for evaluation, not statements of completed customer projects or universal suitability.
07 / FVMQ REQUIREMENTS
FLUID supports custom sealing products, engineered sealing solutions and seal design review for FVMQ requirements.
For a replacement, confirm the existing dimensions, material specification, gland geometry and operating conditions. An O-ring with the same dimensions and hardness is not necessarily an equivalent replacement.
Leakage, swelling, hardening, cuts or wear should be assessed with the service history. Appearance alone cannot distinguish a material compatibility problem from an installation, clearance or operating issue.
Material options, hardness, colour, dimensions, quantities and documentation requirements are reviewed before confirming a supply solution. Do not assume that every combination is available.
08 / REVIEW
Please share the information available:
Drawing, O-ring dimensions, tolerances, sample information or part reference.
Existing material specification, hardness and colour requirements, if known.
Exact fuel, oil or other media, including additives and cleaning exposure.
Minimum and normal temperatures, cold-start conditions and peak exposure duration.
Working pressure, pressure changes and static or dynamic operation.
Gland geometry, clearances, installation arrangement and contact surfaces.
Leakage history, observed damage and the reason for replacement.
Quantity, delivery needs and required material or inspection documents.
You do not need a complete specification to begin. We can identify the information needed for the next stage of review.
09 / RELATED PATHS
10 / TECHNICAL REVIEW FAQ
FVMQ generally offers improved resistance to selected hydrocarbon fuels compared with conventional silicone. The actual fuel composition, temperature and compound still need review. This is not a guarantee of compatibility with every fuel or cleaning chemical.
Consider cold flexibility and fluid compatibility together. Conventional FKM and low-temperature FKM compounds can behave differently, so a comparison should include the proposed compound, cold-start temperature, pressure, motion and gland design. A material-family temperature chart alone is insufficient.
Static sealing is the main application direction. Sliding friction, wear and mechanical strength can restrict dynamic use. Reciprocating and rotary applications require individual assessment rather than a general suitability statement.
No. A published range, a brittleness test and a TR10 result describe different aspects of material behaviour. Finished-seal performance also depends on the compound, squeeze, tolerances, pressure, fluid exposure and temperature history. The existing −60°C reference is not a FLUID finished-product guarantee.
Not automatically. Check material compatibility, hardness, dimensional tolerances, gland fill, squeeze, pressure and installation requirements. A change that improves fluid resistance or cold flexibility may introduce different mechanical or wear limitations.
NEXT STEP
Share your drawing, fluid specification, cold-start conditions or replacement concern. FLUID will review the available information and clarify the next step for material selection, custom manufacturing and seal design support.
Initial response within 12 hours.
