# High Temperature Resistant Pressure Liquid Silicone Insulation Sleeve
Product Overview
The High Temperature Resistant Pressure Liquid Silicone Insulation Sleeve is a high-performance protective component manufactured via injection molding of medical/industrial-grade liquid silicone rubber (LSR), engineered to address the dual demands of extreme thermal stability, high voltage insulation, and mechanical pressure resistance in harsh operating environments. Unlike extruded silicone sleeves with inherent porosity and uneven wall thickness, this LSR-molded sleeve features a fully dense, seamless structure that eliminates leakage paths, delivers consistent material properties across the entire part, and maintains dimensional precision within ±0.02mm for tight-fit installations.
Core selling points include continuous operating temperature resistance up to 220°C (with intermittent tolerance to 300°C for 1000+ hours), 10kV/mm AC dielectric strength, and 15MPa radial compressive load capacity without permanent deformation. The sleeve is inherently flame retardant to UL94 V-0 standard without added halogenated additives, and its non-toxic, low volatile organic compound (VOC) formulation makes it suitable for both industrial and food-contact use cases. It is designed to provide long-term insulation, corrosion resistance, and mechanical protection for wires, busbars, sensors, and pipeline connections in high-stress applications where conventional PVC, EPDM, or extruded silicone sleeves fail prematurely.
Technical Specifications
Material Properties
ParameterTest StandardValueNotes
Base Material-Platinum-cured high-purity liquid silicone rubberNo peroxide residues, low outgassing
HardnessASTM D224030–80 Shore ACustomizable per application requirements
Tensile StrengthASTM D412≥8.5 MPaResists cracking under tensile load
Elongation at BreakASTM D412≥380%Accommodates repeated bending and thermal expansion
Tear StrengthASTM D624≥28 kN/mPrevents propagation of small cuts
Flammability RatingUL94V-0Self-extinguishing within 10 seconds, no dripping
Thermal ConductivityASTM E15300.28 W/(m·K)Balances insulation and heat dissipation for high-power components
Dielectric StrengthIEC 60243-1≥10 kV/mmWithstands transient voltage surges up to 30kV for 1 minute in 2mm thickness
Volume ResistivityIEC 60093≥1×10¹⁶ Ω·cmMaintains insulation performance in high-humidity environments
Compression SetASTM D395 (22h @ 177°C)≤8%Minimal permanent deformation under long-term pressure
Chemical Resistance-Resistant to dilute acids, alkalis, engine oil, hydraulic fluid, and UV radiationAvoids long-term contact with concentrated solvents
Physical Performance
ParameterValue RangeCustomization Option
Inner Diameter1.2mm–150mmCustom diameters available for special busbar or pipe sizes
Wall Thickness0.5mm–10mmThickened walls up to 15mm for high-voltage, high-pressure scenarios
Length5mm–1200mmCut-to-length services with no burr edges
Dimensional Tolerance±0.02mm (≤20mm ID), ±0.5% of nominal value (>20mm ID)Tighter tolerances available for aerospace applications
Operating Temperature Range-60°C to +220°C (continuous), +300°C (intermittent, 1000h)Special formulation available for -70°C to +260°C continuous use
Radial Pressure Resistance10MPa (standard grade), 20MPa (high-pressure grade)Passes 10,000 pressure cycle tests (0 to 15MPa) without cracking
Aging Resistance≥10 years (outdoor exposure), ≥20 years (indoor enclosed use)No discoloration or brittleness after 1000h of xenon lamp UV aging test
Process Parameters
Manufactured via precision liquid silicone injection molding under the following controlled conditions to ensure consistent quality:
Process StepParameter
Material Mixing Ratio1:1 (A/B component platinum-cured LSR)
Injection Pressure80–120 MPa
Mold Temperature170–190°C
Curing Time30–90 seconds (varies by wall thickness)
Post-Curing2h @ 200°C (optional, for low-outgassing requirements)
Secondary ProcessingPunching, slitting, adhesive coating, surface corona treatment available
Product Advantages
1. Unmatched High-Temperature Pressure Stability
Unlike extruded silicone sleeves that suffer from dimensional shrinkage, brittleness, and insulation degradation at temperatures above 180°C, this LSR molded sleeve retains 90% of its original mechanical and electrical properties after 1000 hours of continuous operation at 220°C. Its fully dense structure resists radial compression up to 15MPa without permanent deformation, making it suitable for high-pressure pipeline and downhole sensor applications where conventional sleeves collapse or leak under combined heat and pressure load.
2. Superior Insulation Reliability in Harsh Environments
The platinum-cured LSR formulation eliminates the porosity and residual impurities common in peroxide-cured extruded silicone, delivering a consistent 10kV/mm dielectric strength even after 500 hours of immersion in 95% relative humidity or salt spray. Unlike PVC sleeves that lose insulation capacity at temperatures above 80°C, this sleeve maintains a volume resistivity of 1×10¹⁶ Ω·cm across its full operating temperature range, eliminating the risk of arc flash and short circuits in high-voltage power distribution systems.
3. Long Service Life with Minimal Maintenance
The sleeve’s inherent UV resistance, ozone resistance, and corrosion resistance reduce aging rates by 60% compared to EPDM and neoprene sleeves. It passes 10,000 bending cycles (180° bend, 1Hz frequency) without cracking, and its low compression set ensures a tight, consistent seal around components even after 10 years of use, eliminating the need for frequent replacement and reducing maintenance costs in hard-to-access installations such as wind turbine nacelles and underground power grids.
4. Compliance with Global Safety and Environmental Standards
The formulation is free of halogens, phthalates, heavy metals, and BPA, meeting RoHS 2.0, REACH SVHC, and California Prop 65 requirements. Food-contact grade variants are FDA 21 CFR 177.2600 and EU 10/2011 certified, while medical grade variants meet ISO 10993-5 biocompatibility standards for non-implantable medical devices. All grades are UL94 V-0 flame retardant, making them suitable for use in enclosed spaces with strict fire safety requirements.
Applications
New Energy Industry
- Lithium battery pack module busbar insulation: Protects high-voltage busbars in electric vehicle (EV) and energy storage system (ESS) packs, withstanding 150°C operating temperatures and mechanical vibration during vehicle operation, while preventing short circuits caused by coolant leakage.
- Wind turbine generator coil and cable protection: Insulates power cables in nacelles that are exposed to -40°C to 180°C temperature swings, high humidity, and 6kV operating voltages, with a 20-year design life matching the turbine’s service cycle.
- Solar inverter internal wiring insulation: Resists UV exposure and high rooftop temperatures up to 120°C, delivering reliable insulation for DC power cables with 1500V operating voltage.
Industrial Electrical and Petrochemical
- High-voltage switchgear and transformer bushing insulation: Covers copper busbars in 10kV–35kV distribution switchgear, withstanding 200°C transient temperatures during short-circuit events and preventing arc flash accidents.
- Downhole sensor and pipeline connection protection for oil and gas exploration: Withstands 180°C downhole temperatures, 15MPa pressure, and corrosion from crude oil and hydrogen sulfide, providing insulation for sensor cables and sealing for pipeline joints.
- Electric furnace and industrial heating equipment wiring protection: Insulates power cables for high-temperature heating elements operating at up to 220°C, resisting thermal aging and exposure to industrial dust and chemicals.
Medical and Food Processing
- Medical device cable insulation for surgical instruments and diagnostic equipment: Medical-grade variants are biocompatible, sterilizable via autoclave (121°C, 2 bar) or ethylene oxide (EO), and provide reliable insulation for high-voltage surgical electrosurgery (ESU) cables.
- Food processing equipment wiring and pipeline sealing: Food-contact grade variants are safe for contact with dairy, meat, and beverage products, withstanding high-temperature cleaning cycles (180°C hot water, steam) and providing insulation for wiring in ovens, filling machines, and conveyor systems.
Aerospace and Defense
- Aircraft wiring harness protection: Low-outgassing variants meet ASTM E595 space material requirements, withstanding extreme temperature swings from -60°C to 200°C and high vibration during flight, while delivering consistent insulation for avionics power cables.
- Military vehicle and naval equipment cable protection: Resists salt spray, shock, and 10kPa overpressure from explosions, providing insulation for communication and power cables in armored vehicles and shipboard systems.
Selection Guide
Hardness Selection
- 30–40 Shore A: Recommended for applications requiring high flexibility and sealing performance, such as irregular-shaped component insulation, pipeline joint sealing, and dynamic bending cable protection. The soft material conforms to uneven surfaces and accommodates frequent movement without cracking.
- 50–60 Shore A: General-purpose grade suitable for most busbar insulation, static cable protection, and moderate pressure applications, balancing flexibility and structural stability.
- 70–80 Shore A: Recommended for high-pressure, high-load scenarios such as downhole sensor protection, high-voltage switchgear busbar sleeves, and applications requiring resistance to mechanical impact and abrasion.
Size Specifications
- Measure the outer diameter of the component to be protected; select an inner diameter 0.1–0.3mm smaller than the component outer diameter for a tight, interference fit that prevents slipping and ingress of dust or moisture.
- For high-voltage applications (>1kV), select a wall thickness of at least 1mm per 3kV of operating voltage to ensure sufficient dielectric strength; for example, 10kV systems require a minimum 3.5mm wall thickness.
- For high-pressure applications (>10MPa), select a wall thickness of at least 20% of the inner diameter to resist collapse under load.
- Custom cut-to-length sizes are available for applications requiring specific installation lengths, with no additional tooling cost for orders over 1000 units.
Material Grade
- Industrial Grade: Cost-effective option for general electrical, automotive, and industrial applications, meeting RoHS and REACH requirements, suitable for non-food, non-medical use cases.
- Food Contact Grade: FDA 21 CFR 177.2600 and EU 10/2011 certified, suitable for direct contact with food and beverage products in processing equipment.
- Medical Grade: ISO 10993-5 biocompatibility certified, sterilizable, intended for use in non-implantable medical devices and surgical equipment.
- Low-Outgassing Aerospace Grade: Meets ASTM E595 requirements (total mass loss <1%, collected volatile condensable materials <0.1%), suitable for aerospace, satellite, and cleanroom applications.
Quality Assurance
All High Temperature Resistant Pressure Liquid Silicone Insulation Sleeves are manufactured in an ISO 9001:2015 certified facility, with a strict three-stage quality control process:
- Incoming material inspection: Each batch of LSR raw material is tested for hardness, tensile strength, and dielectric strength to confirm compliance with formulation specifications.
- In-process inspection: 100% of parts undergo dimensional measurement, visual inspection for defects (bubbles, cracks, uneven wall thickness), and random sampling for pressure and high-temperature aging testing during production.
- Finished product inspection: Pre-shipment testing includes dielectric strength verification, flame retardancy testing, and compression set testing, with a batch pass rate of ≥99.8%.
The product is certified to UL E486793, RoHS 2.0, REACH SVHC, and CE LVD standards, with food and medical grade variants holding FDA and ISO 10993 certifications respectively. We offer a 5-year warranty against defects in material and workmanship for standard industrial grade products, with a 3-year warranty for special grades. In the event of product performance failure due to manufacturing defects within the warranty period, we provide free replacement or full refund. Customized products are supported by a free prototyping service (lead time 3–5 working days) with full performance validation prior to mass production.
