Silicone hose buys you two things no common elastomer matches together: a continuous temperature range of roughly −60…+230 °C and biocompatibility (platinum-cured grades to USP Class VI). Before specifying, fix its three hard limits, silicone swells in fuels, oils and aromatics (use FVMQ or PTFE there), it is not suitable for concentrated chemicals, and it must never be used for high-pressure steam, which belongs to EN ISO 6134 steam hose with bolted safety clamps.
This article is the pre-specification checklist. For the full reference see the complete silicone hose technical guide, and for parameter tables Silicone Hose: Specifications Explained.
What Silicone Is, and Isn't
Silicone (polydimethylsiloxane, PDMS) keeps its elasticity across a huge thermal window, shrugs off ozone and UV that crack conventional rubber, takes autoclave sterilisation, and in platinum-cured form is the standard flexible material of biopharma. Its mechanical trade-off: tensile strength around 8–12 MPa versus 14–20 MPa for NBR/EPDM, which is why silicone hose lives in the low-pressure world, typically full vacuum (with helix) up to ~15 bar with fabric reinforcement, and has no place in impulse hydraulics.
Chemistry boundaries, per material science rather than marketing:
- Good: water, aqueous media, alcohols, dilute solutions, air and inert gases, food media (with the right certificates), sterilisation cycles.
- Bad: fuels, mineral oils, aromatic solvents (swelling), concentrated acids and alkalis, ketones in aggressive service, and high-pressure steam. Autoclave/SIP cycles at up to ~134 °C are silicone territory; pressurised steam lines are not. For those, see the steam hose technical guide.
- Fuel-adjacent duty: fluorosilicone (FVMQ) keeps most of the thermal range while resisting fuels and oils; for broad chemistry go to PTFE, compare in the PTFE hose specification guide.
Construction and Types
Manufacture: HCR silicone gum (peroxide- or platinum-catalysed) extruded or mandrel-built, with polyester/aramid plies or braid added for pressure, then vulcanised. Post-curing drives off volatiles and is mandatory for food and pharmaceutical grades.
| Type | Reinforcement | Typical WP* | Vacuum | Typical use |
|---|---|---|---|---|
| Unreinforced extruded | none | 2–4 bar | limited | Lab lines, peristaltic tubing |
| Single-ply braided | 1 textile ply | 6–10 bar | limited | Coolant, air, water |
| Multi-ply braided | 2–4 plies | 10–15 bar | limited | Charge-air, hot-water transfer |
| Wire-helix suction | plies + steel helix | 4–8 bar | full vacuum | Suction and transfer |
| Moulded shapes (elbows, reducers) | plies | as parent hose | — | Tight routing without bending |
*Typical mid-bore values at 20 °C: working pressure falls as bore rises and derates with temperature, read the size-specific datasheet, and remember unreinforced tubing is designed with a higher (5:1) burst safety factor than braided hose (4:1), while the proof test remains about 1.5× WP.
Cure system matters commercially: peroxide-cured silicone needs thorough post-cure to remove by-products and can still carry taste/odour traces; platinum (addition) cured silicone leaves no organic residues, has lower extractables, and is the default for pharma and premium food duty.
Certificates: Get the Citations Right
- FDA 21 CFR 177.2600, the correct US citation for silicone (a rubber article), not 177.1550 (that is PTFE).
- EC 1935/2004 with GMP 2023/2006, the EU framework. Regulation 10/2011/EU covers plastics only and does not apply to silicone; a declaration citing 10/2011 for a silicone hose is citing the wrong regulation. National rubber/silicone rules (e.g. BfR XV) fill the gap.
- USP Class VI and extractables documentation for pharmaceutical duty; 3-A where dairy practice requires it.
- Every certificate applies to a specific medium and hose version, including pigment. A blue identification stripe changes the compliance question; confirm the pigmented compound is covered.
For the hygienic-assembly picture (fittings, Ra values, documentation packages), see the pharmaceutical hose guide.
Buyer's Checklist
- Medium: aqueous/food/pharma → silicone; fuels and oils → FVMQ; solvents, aromatics, concentrated chemicals or pressurised steam → different hose family.
- Temperature: continuous and peak; above ~200 °C continuous, specify the post-cured high-temperature grade.
- Pressure with surge, at temperature, per bore, and a 4:1 burst factor on braided constructions.
- Vacuum: any suction duty needs the wire-helix construction rated to full vacuum.
- Bend radius: typically 2.5–4× ID; tighter routing means a factory-moulded elbow, not a forced bend.
- Cure system: platinum for pharma/premium food; peroxide with documented post-cure otherwise.
- Certificates for the exact version: FDA 177.2600, EC 1935/2004 + GMP 2023/2006, USP Class VI as needed, medium-specific.
- End connections: silicone takes barbed tails with clamps or hygienic ends — Tri-Clamp per DIN 32676 and DIN 11851 being different, non-interchangeable systems. Constant-tension clamps compensate for silicone's thermal expansion and compression set.
- Traceability: batch numbers, material certificates, retained samples for pharma.
Browse silicone products under industrial hoses or search directly for silicone hose; clamps and hygienic couplings are under industrial fittings.
Installation Notes That Prevent Most Failures
- Do not over-torque worm-drive clamps, silicone compresses easily and the clamp edge cuts the wall; follow the torque specification or use constant-tension spring clamps.
- No petroleum-based assembly lubricants, water or food-grade silicone-compatible lubricant only.
- Leave slack: silicone's thermal expansion is high; never route in tension, and keep hoses off sharp edges with lined clips.
- Respect the bend radius; order moulded elbows for tight geometry.
- Pressure-test at 1.5× working pressure with water, record the batch and installation date.
Inspection and Failure Modes
Silicone rarely ozone-cracks, so surface degradation usually signals chemical attack instead. A tacky bore means hydrocarbon contamination (wrong medium or lubricant). A blister or circumferential bulge means moisture entered the reinforcement and delaminated the plies at temperature: replace immediately, the burst margin is gone. Weeping at flanged joints after thermal cycling points to compression set, specify a lower-set compound or revise the joint. In food CIP duty, plan replacement when bore surface roughness rises and cleanability drops; in peristaltic duty, replace on cycle count.
Correctly specified, silicone commonly outlasts EPDM by a factor of about three in hot service, the basis of its total-cost case.
Cost and Total Cost of Ownership
Silicone carries a 3–5× unit premium over EPDM of the same bore. In hot, cyclic or hygiene-critical duty the premium reverses quickly: fewer change-outs, less downtime, and in food plants fewer CIP-validation events. In cool, benign water duty EPDM remains the rational choice, silicone earns its price where temperature, sterilisation or biocompatibility are on the requirement list, not everywhere.
Specify with Support
Tubes International supplies industrial and food/pharma silicone hose, platinum- and peroxide-cured, with moulded shapes, matched clamps and hygienic fittings, and medium-specific compliance declarations. Start from industrial hoses, check the PDF catalogues, or send your medium and temperature profile, our engineering team selects the hose and fittings and pressure-tests the complete assembly.