VMQ Solid Silicone Joint Sealing Ring

Thermal cycling, vibration, and fluid pressure converge at every pipe joint — and that’s exactly where this VMQ solid silicone sealing ring earns its keep. Engineered from high-purity methyl vinyl silicone rubber, it delivers reliable compression sealing across a continuous service range of -60°C to +200°C, with hardness tunable from 50 to 70 Shore A…

Specifications

Product Type:

Compression-Molded Gasket / Joint Sealing Ring

Base Polymer:

VMQ (Methyl Vinyl Silicone Rubber)

Structure:

Solid

Color: 

Translucent white (standard); custom colors available (red, blue, grey, black, pantone matching)

Surface Finish:

Smooth (Ra ≤ 1.6 μm typical)

Standards & Compliance: 

Hardness:

50–70 Shore A (standard 60 ± 5 Shore A)

Tensile Strength: 

≥ 20 kN/m

Elongation at Break:

≥ 300%

Tear Strength:

≥ 20 kN/m

Recommended Service Temperature:

-60°C to +200°C (intermittent to +230°C)

Hot Air Aging:

200°C × 72h: Hardness change ≤ ±5 Shore A

Low‑Temperature Brittleness: 

≤ -60°C

Typical Applications:

Pipe joint gasket, hose coupling seal, tank fitting seal, dishwasher arm connection, water purification module seal

Description:

Most joint failures don’t happen because the gasket was too weak. They happen because the gasket couldn’t keep up with what the system was doing — thermal expansion pulling the flanges apart at 180°C, then contraction squeezing them back together at ambient, over and over, thousands of cycles a year. VMQ silicone addresses this problem at the molecular level. Its Si–O–Si backbone is inherently more thermally stable than carbon-chain elastomers, maintaining elastic recovery across a 260°C operating window that would destroy NBR or EPDM joints. The methyl and vinyl side groups give the compounder precise control over crosslink density, which translates directly to compression set resistance — the single most critical property for any static seal sitting in a groove under sustained bolt load.

Low compression set means the ring pushes back. Even after months of continuous clamping at elevated temperature, a properly formulated VMQ gasket retains enough stored elastic energy to track flange movement caused by vibration or thermal cycling. That’s not marketing language. That’s what keeps a dishwasher arm from dripping and a chemical process coupling from weeping.

Typical Industry Applications

Proven performance across demanding manufacturing environments.

Industry Typical Use Cases
Home Appliances Dishwasher spray arm connection seal, washing machine inlet/outlet coupling gasket, water purifier module joint ring
Food & Beverage Equipment Beverage dispenser hose coupling seal, food-grade pipe flange gasket, dairy processing fitting ring
Plumbing & Water Treatment Potable water pipe joint gasket, water meter coupling seal, water heater inlet/outlet ring
HVAC & Mechanical Systems Chiller pipe coupling gasket, pump suction/discharge flange seal, coolant hose connection ring
Automotive & Motorcycle Coolant hose coupling seal, EGR tube connection gasket, intercooler pipe joint ring
Industrial Machinery Pneumatic fitting seal, hydraulic tank drain fitting gasket, chemical dosing line coupling ring

Chemical Resistance Table:

Chemical / Medium Resistance Notes
Water (hot & cold) ✅ Excellent Suitable for continuous immersion to 100°C
Steam (low pressure) ✅ Excellent Short-term exposure up to 150°C
Dilute acids (≤ 10%) ✅ Excellent Acetic, citric, phosphoric
Dilute alkalis (≤ 10%) ✅ Excellent Sodium hydroxide, ammonia solutions
Ethanol / isopropanol ✅ Excellent Common sanitizing agents
Food-grade oils (vegetable) ✓ Good Moderate swelling over extended exposure
Mineral oils ⚠ Limited Noticeable swelling; not recommended for continuous immersion
Petroleum fuels (gasoline, diesel) ✗ Not recommended Rapid swelling and property loss
Ozone / UV ✅ Excellent Inherent resistance; no antiozonants needed
Hydrogen peroxide (≤ 3%) ✅ Excellent Compatible with CIP sanitizing cycles
Silicone fluids ✅ Excellent Minimal interaction
Chlorinated water ✓ Good Suitable for municipal water systems
Aromatic solvents (toluene, xylene) ✗ Not recommended Severe swelling
Ketones (acetone, MEK) ✗ Not recommended Significant volume change
Concentrated acids (>30%) ⚠ Limited Short-term contact only; consult for specific acid

In-House Quality Assurance & Testing:

At Micune Rubber, batch-to-batch consistency is guaranteed through our ISO-9001 certified Quality Management System. Every rubber compound and custom extrusion undergoes rigorous evaluation in our dedicated testing laboratory before shipment. We utilise industry-standard baseline testing, including Mooney Viscometers to measure compound viscosity and Torque Rheometers to verify exact vulcanisation characteristics. This ensures every material formulation strictly adheres to your required specifications and processing parameters.

Mooney Viscometer

Mooney Viscometer

abrasive testing machine

Abrasive Testing Machine

Burn-in Chamber

Burn-in Chamber

Torque Rheometer

Torque-Rheometer

RFQ:

Standard compression-molded tolerances follow ISO 3302-1 Class M2, which for a typical joint ring means ID/OD tolerance of ±0.15 mm and cross-section tolerance of ±0.10 mm on dimensions under 25 mm. Tighter tolerances down to Class M1 are achievable with precision tooling — specify your target dimensions and tolerance requirements when submitting the RFQ.

The food-contact VMQ grade is tested by CTI (Centre Testing International) against GB 4806.16-2025, covering sensory evaluation, overall migration, potassium permanganate wastage, volatile matter, and heavy metals — all passing. SGS RoHS and PAHs test reports are also available. Certificates are provided with shipment upon request.

Hardness is adjustable from 40 to 80 Shore A; the most common joint-seal range is 50–70 Shore A, selectable based on groove depth and compression percentage. Custom colors including Pantone-matched options are available at no surcharge on orders above MOQ, and non-standard cross-section profiles (X-ring, quad-ring, stepped) can be tooled to drawing.

If existing tooling matches the required dimensions, samples ship within 5–7 working days. For new tooling, mold fabrication takes 10–15 working days, after which initial samples are molded and shipped for approval within 3 days. Expedited timelines are available for urgent projects — confirm your target date when inquiring.

MOQ is typically 500 pieces per size/specification for molded rings; smaller trial quantities can be negotiated for new development projects. Rings are individually sealed in PE bags, packed in cartons with silica gel desiccant, and shipped via sea freight or express courier depending on urgency and destination.

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