Speciality Silicone Tubing
When standard VMQ silicone does not meet the requirement — oil and solvent resistance, electrical conductivity, regulated fire behaviour, cellular insulation — we have speciality formulations developed to solve specific technical problems.
Standard VMQ silicone (Series 2, 12) is an exceptionally versatile material, but it has well-known limitations: it swells on contact with hydrocarbons and organic solvents, it does not conduct electricity, it cannot on its own meet the most stringent fire-behaviour requirements, and in its solid form it does not offer thermal insulation comparable to cellular materials. When the application requires one of these limitations to be overcome, speciality formulations designed specifically for that purpose are available.
Fluorosilicone (FVMQ, Series 13) incorporates fluorine into the polymer chain, conferring resistance to oils, fuels and organic solvents that would degrade standard VMQ. Conductive silicone (Series 11) incorporates carbon fillers that reduce volume resistivity to dissipate static charges. Series 16 adds flame-retardant additives enabling compliance with EN 45545-2 for railway rolling stock. Cellular silicone (Series 15, Series 33) expands during vulcanisation, creating a closed-cell structure with a density between 0.5 and 0.8 g/cm3. Series 22 offers specific stability against steam and aromatic oils.
These formulations are manufactured under technical review: we analyse the application, validate compatibility and confirm extrusion feasibility before production. Lead times are longer than for standard tubing due to the lower throughput of these compounds and the need for prior technical validation.
Do you genuinely need a speciality formulation?
Before specifying a speciality tube, it is worth verifying that a standard VMQ (Series 2 or Series 12) cannot solve the problem with a design adjustment: a thicker wall, an external coating or a change in hardness may be sufficient for many applications. Speciality formulations are more expensive and have longer lead times. However, when the requirement is genuine — fuel contact, railway regulation, ESD dissipation — there is no alternative within the standard silicone family.
Which speciality tube do you need?
Locate your dominant technical requirement to determine the formulation family. If your application combines two requirements (e.g. oils + high temperature), enquire about the available combination.
| Requisito | Formulación | Serie | Proceso |
|---|---|---|---|
| Contact with mineral oils / fuels | FVMQ Fluorosilicone | Serie 13 | Extrusion under review |
| Contact with organic solvents | FVMQ Fluorosilicone | Serie 13 | Extrusion under review |
| Hydraulic fluids | FVMQ Fluorosilicone | Serie 13 | Extrusion under review |
| Electrostatic discharge dissipation (ESD) | Conductive VMQ | Serie 11 | Extrusion under review |
| ATEX zone — ignition risk | Conductive VMQ | Serie 11 | Extrusion under review |
| Railway EN 45545-2 (solid) | Flame-retardant VMQ | Serie 16 | Extrusion |
| Railway EN 45545-2 (cellular) | Flame-retardant cellular silicone | Serie 33 | Extrusion |
| Thermal insulation / soft sealing | Cellular silicone | Serie 15 | Extrusion |
| Steam + aromatic oils | VMQ Steam/oil-resistant | Serie 22 | Extrusion |
| Oils + high temperature (+220 °C) | FVMQ + HT additive | Serie 13 + HT | Extrusion under review |
Speciality tube types by requirement
Fluorosilicone tubing (FVMQ)
Series 13 formulation with FVMQ base: the polymer chain incorporates trifluoropropyl groups that confer resistance to mineral oils, fuels (petrol, diesel, kerosene), organic solvents and hydraulic fluids. It retains the low-temperature flexibility (–60 °C) characteristic of silicones, but with a chemical resistance that standard VMQ cannot offer. Service temperature up to +170 °C, extendable to +220 °C with HT additive.
Conductive / antistatic tubing (ESD)
Series 11 formulation with carbon fillers that reduce volume resistivity. Dissipates electrostatic charges that accumulate during the flow of fluids or powders, preventing discharges that could damage sensitive electronic components, cause ignition in explosive atmospheres (ATEX) or generate quality defects. Available in black only. Hardnesses 50 and 70 Shore A.
Flame-retardant railway tubing (EN 45545-2)
Series 16 (solid) and Series 33 (cellular) formulations with enhanced fire resistance, tested to EN 45545-2 version 2020. They meet the fire/smoke requirements R22 and R23 up to hazard level HL3 (Series 16) and HL2 (Series 33). Tests include oxygen index (LOI), optical smoke density (Ds max) and conventional toxicity index (ITCPNL). Hardnesses from 30 to 85 Shore A.
Cellular / sponge tubing
Series 15 (platinum, FDA) and Series 33 (platinum, EN 45545-2) formulations with closed-cell structure. Density between 0.5 and 0.8 g/cm3 depending on wall thickness. Combines thermal insulation, compressibility for sealing and light weight. The cellular structure provides much softer compression than solid silicone, ideal for seals requiring low closing force.
Dimensional ranges by speciality family
The dimensional ranges for speciality tubing are more limited than those for standard silicones, as extrusion behaviour varies with formulation. Fluorosilicone and conductive silicone require specific process adjustments. Cellular silicone has minimum wall-thickness restrictions to develop the cell structure. All require prior technical review.
Fluorosilicone FVMQ
ID 3 to 50 mmStandard extrusion range for fluorosilicone. The FVMQ compound has a higher density (1.40–1.46 g/cm3) than standard VMQ, which affects tube weight. Wall thicknesses from 1 mm. Fluorosilicone is stiffer than VMQ at equal hardness, limiting bend radii at small diameters.
- Inside diameter
- 3 to 50 mm
- Wall thickness
- 1 to 5 mm
- Typical supply form
- Cut lengths or short coils
Formulations: Series 13 (FVMQ peroxide, 40–70 ShA). HT additive available for +220 °C.
Conductive ESD
ID 2 to 30 mmConductive silicone extrusion requires careful process control: carbon fillers affect compound flow and resistivity uniformity. Available in black only. Mechanical properties are lower than standard VMQ (tensile 5 MPa, tear 5–10 kN/m), limiting use to applications without high mechanical stress.
- Inside diameter
- 2 to 30 mm
- Wall thickness
- 1 to 3 mm
- Typical supply form
- Cut lengths
Formulations: Series 11 (conductive VMQ peroxide, 50/70 ShA). Black only.
Flame-retardant railway
ID 4 to 60 mmWide extrusion range. Series 16 (solid) is available from 30 to 85 Shore A with good mechanical properties (tensile up to 9 MPa, tear up to 25 kN/m). Series 33 (cellular) is manufactured without a defined Shore hardness — its compressibility is determined by density and wall thickness.
- Inside diameter
- 4 to 60 mm
- Wall thickness
- 2 to 8 mm (solid) / 3 to 15 mm (cellular)
- Typical supply form
- Cut to length
Formulations: Series 16 solid (R22/R23 HL1–HL3), Series 33 cellular (R22/R23 HL1–HL2).
Cellular / sponge
ID 5 to 80 mmCellular silicone requires a minimum wall thickness for the cell structure to develop correctly. Thicknesses below 3 mm do not allow uniform expansion. Density varies between 0.5 and 0.8 g/cm3 depending on wall thickness — thicker walls develop lower densities.
- Inside diameter
- 5 to 80 mm
- Wall thickness
- 3 to 20 mm
- Typical supply form
- Cut to length
Formulations: Series 15 (platinum, FDA, CE 1935/2004), Series 33 (platinum, EN 45545-2 HL1–HL2).
All speciality tubing requires a prior technical review. The dimensional ranges shown are indicative and depend on extrusion validation for each specific combination of formulation, diameter and wall thickness. Tolerances: ISO 3302-1 E1/E2 (solid), E3 (cellular).
Which speciality formulation do you need?
Fluorosilicone FVMQ — oil and solvent resistance (Series 13)
FVMQ base with trifluoropropyl groups in the polymer chain. Resists mineral oils, fuels, organic solvents and hydraulic fluids where standard VMQ would swell and lose properties. Temperature –60 to +170 °C, extendable to +220 °C with HT additive.
Fuel circuits, oil lines, solvent environments, engine-bay protection with oil, hydraulic fluid connections.
| Property | EQ1340 | EQ1350 | EQ1360 | MQ1370 |
|---|---|---|---|---|
| Hardness (±5 Shore A) | 40 | 50 | 60 | 70 |
| Tensile strength (MPa min) | 6 | 6 | 7 | 7 |
| Elongation (% min) | 400 | 230 | 230 | 160 |
| Tear strength (kN/m min) | 10 | 12 | 21 | 21 |
| Density (g/cm3) | 1.40 | 1.41 | 1.46 | 1.46 |
Temperature: –60 to +170 °C (+220 °C with HT additive). The high density (1.40–1.46) is due to fluorine incorporation. EQ1360 and MQ1370 offer respectable tear strength (21 kN/m). MQ1370 available in moulding only. RAL colours available.
Conductive VMQ — ESD dissipation (Series 11)
Silicone with carbon fillers that reduce volume resistivity below 12 ohm-cm (50 ShA) and 4 ohm-cm (70 ShA). Dissipates electrostatic charges in applications where static build-up poses a risk of ignition, component damage or quality defects.
ATEX zones, pneumatic powder transport, ESD cable protection, sensitive electronics environments, cleanrooms with electrostatic control.
| Property | EQ1150 | EQ1170 |
|---|---|---|
| Hardness (±5 Shore A) | 50 | 70 |
| Tensile strength (MPa min) | 5 | 5 |
| Elongation (% min) | 250 | 100 |
| Tear strength (kN/m min) | 5 | 10 |
| Density (g/cm3) | 1.11 | 1.16 |
| Volume resistivity (ohm-cm) | <= 12 | <= 4 |
Temperature: –50 to +210 °C. Available in black only. Mechanical properties lower than standard VMQ due to carbon fillers. Extrusion possible subject to technical review. Peroxide cure.
Flame-retardant VMQ — railway EN 45545-2 (Series 16)
Solid formulation with enhanced fire resistance, tested to EN 45545-2 version 2020. Meets R22 and R23 up to HL3 in extrusion (PEQ) and moulding (PMQ). Good mechanical properties: tensile up to 9 MPa, tear up to 25 kN/m. Hardness range 30 to 85 Shore A.
Railway rolling stock (trains, metros, tramways), components in passenger zones, regulated penetration seals.
| Property | EQ1630 | EQ1650 | EQ1660 | EQ1670 |
|---|---|---|---|---|
| Hardness (±5 Shore A) | 30 | 50 | 60 | 70 |
| Tensile strength (MPa min) | 5 | 8 | 9 | 9 |
| Elongation (% min) | 850 | 480 | 450 | 380 |
| Tear strength (kN/m min) | 25 | 18 | 20 | 20 |
| Density (g/cm3) | 1.09–1.17 | 1.14–1.23 | 1.18–1.26 | 1.18–1.26 |
Temperature: –60 to +200 °C. EN 45545-2 R22/R23: LOI 32.7 % (EQ) / 35.1 % (MQ), Ds max 84.7 (EQ) / 45 (MQ), ITCPNL 0.06. Hazard level achieved: HL1, HL2, HL3. Colours: black RAL 9017, blue-black RAL 5004 (EQ); black, grey, cream (MQ). Series 33 cellular available for R22/R23 HL1–HL2.
Cellular sponge silicone — insulation and sealing (Series 15)
Platinum-cured silicone with closed-cell structure. Density between 0.5 and 0.8 g/cm3 depending on wall thickness. Combines thermal insulation, light weight and soft compressibility. FDA, CE 1935/2004 and BfR certifications available. For flame-retardant applications, Series 33 cellular meets EN 45545-2 R22/R23 HL1–HL2.
Thermal insulation of ducts, low-force seals, vibration damping, condensation protection, cable-entry tubes in panels with soft closure.
| Property | EQ1510 |
|---|---|
| Tensile strength (MPa min) | 3 |
| Elongation (% min) | 600 |
| Tear strength (kN/m min) | 15 |
| Density (g/cm3) | 0.5–0.8 |
Temperature: –60 to +200 °C. Platinum cure. Density varies with wall thickness: thicker walls allow greater expansion and lower density. Dimensional tolerances E3 (cellular). Certifications: FDA, CE 1935/2004, BfR (formulation dependent).
FVMQ base with trifluoropropyl groups in the polymer chain. Resists mineral oils, fuels, organic solvents and hydraulic fluids where standard VMQ would swell and lose properties. Temperature –60 to +170 °C, extendable to +220 °C with HT additive.
Fuel circuits, oil lines, solvent environments, engine-bay protection with oil, hydraulic fluid connections.
| Property | EQ1340 | EQ1350 | EQ1360 | MQ1370 |
|---|---|---|---|---|
| Hardness (±5 Shore A) | 40 | 50 | 60 | 70 |
| Tensile strength (MPa min) | 6 | 6 | 7 | 7 |
| Elongation (% min) | 400 | 230 | 230 | 160 |
| Tear strength (kN/m min) | 10 | 12 | 21 | 21 |
| Density (g/cm3) | 1.40 | 1.41 | 1.46 | 1.46 |
Temperature: –60 to +170 °C (+220 °C with HT additive). The high density (1.40–1.46) is due to fluorine incorporation. EQ1360 and MQ1370 offer respectable tear strength (21 kN/m). MQ1370 available in moulding only. RAL colours available.
Silicone with carbon fillers that reduce volume resistivity below 12 ohm-cm (50 ShA) and 4 ohm-cm (70 ShA). Dissipates electrostatic charges in applications where static build-up poses a risk of ignition, component damage or quality defects.
ATEX zones, pneumatic powder transport, ESD cable protection, sensitive electronics environments, cleanrooms with electrostatic control.
| Property | EQ1150 | EQ1170 |
|---|---|---|
| Hardness (±5 Shore A) | 50 | 70 |
| Tensile strength (MPa min) | 5 | 5 |
| Elongation (% min) | 250 | 100 |
| Tear strength (kN/m min) | 5 | 10 |
| Density (g/cm3) | 1.11 | 1.16 |
| Volume resistivity (ohm-cm) | <= 12 | <= 4 |
Temperature: –50 to +210 °C. Available in black only. Mechanical properties lower than standard VMQ due to carbon fillers. Extrusion possible subject to technical review. Peroxide cure.
Solid formulation with enhanced fire resistance, tested to EN 45545-2 version 2020. Meets R22 and R23 up to HL3 in extrusion (PEQ) and moulding (PMQ). Good mechanical properties: tensile up to 9 MPa, tear up to 25 kN/m. Hardness range 30 to 85 Shore A.
Railway rolling stock (trains, metros, tramways), components in passenger zones, regulated penetration seals.
| Property | EQ1630 | EQ1650 | EQ1660 | EQ1670 |
|---|---|---|---|---|
| Hardness (±5 Shore A) | 30 | 50 | 60 | 70 |
| Tensile strength (MPa min) | 5 | 8 | 9 | 9 |
| Elongation (% min) | 850 | 480 | 450 | 380 |
| Tear strength (kN/m min) | 25 | 18 | 20 | 20 |
| Density (g/cm3) | 1.09–1.17 | 1.14–1.23 | 1.18–1.26 | 1.18–1.26 |
Temperature: –60 to +200 °C. EN 45545-2 R22/R23: LOI 32.7 % (EQ) / 35.1 % (MQ), Ds max 84.7 (EQ) / 45 (MQ), ITCPNL 0.06. Hazard level achieved: HL1, HL2, HL3. Colours: black RAL 9017, blue-black RAL 5004 (EQ); black, grey, cream (MQ). Series 33 cellular available for R22/R23 HL1–HL2.
Platinum-cured silicone with closed-cell structure. Density between 0.5 and 0.8 g/cm3 depending on wall thickness. Combines thermal insulation, light weight and soft compressibility. FDA, CE 1935/2004 and BfR certifications available. For flame-retardant applications, Series 33 cellular meets EN 45545-2 R22/R23 HL1–HL2.
Thermal insulation of ducts, low-force seals, vibration damping, condensation protection, cable-entry tubes in panels with soft closure.
| Property | EQ1510 |
|---|---|
| Tensile strength (MPa min) | 3 |
| Elongation (% min) | 600 |
| Tear strength (kN/m min) | 15 |
| Density (g/cm3) | 0.5–0.8 |
Temperature: –60 to +200 °C. Platinum cure. Density varies with wall thickness: thicker walls allow greater expansion and lower density. Dimensional tolerances E3 (cellular). Certifications: FDA, CE 1935/2004, BfR (formulation dependent).
Speciality tube development
Speciality tubing follows a more detailed development process than standard tubing: the compound has different extrusion behaviour and requires prior technical validation. The objective is to confirm that the speciality formulation can be extruded in the required geometry with the expected properties.
Application sectors
Railway
Flame-retardant tubing and profiles to EN 45545-2 for rolling stock: trains, metros and tramways.
Industrial
Fluorosilicone and conductive tubing for machinery with oils, solvents or ESD risk.
Pharmaceutical
Cellular and speciality tubing for pharmaceutical equipment with insulation and purity requirements.
Electronics
Conductive ESD tubing for component and cable protection in sensitive environments.
Related products
Industrial tubing
Standard VMQ tubing for applications without speciality requirements.
High-temperature tubing
VMQ tubing with thermal stability up to +300 °C.
Reinforced tubing
Tubing with mesh reinforcement for pressure and vacuum lines.
Custom profiles
Extruded profiles available in all speciality formulations.
Need silicone tubing with speciality properties?
Describe the technical problem: the fluid, the temperature, the applicable regulation or the required electrical property. Our technical team will assess feasibility, confirm the most suitable formulation and provide a quotation with a realistic delivery lead time.
Enquire about technical feasibility