Custom Multi-Bore Alumina Tube with OD 3–220mm, Hole Dia 0.25–10mm, Length up to 3000mm

Applications for Multi-Bore Alumina Tube

• Thermocouple Protection in High-Temperature Furnaces

  ✅Key Advantages

  1. Multi-point sensing in confined space
  Allows up to 8 thermocouple wires in a single tube with OD ≤ 12mm, reducing port usage by 60%.

  2. Consistent thermal response across channels
  Uniform wall thickness and bore spacing ensure <3°C deviation between adjacent thermocouple readings at 1200°C.

  3. Simplified furnace wall penetration
  Single-sheath design reduces feedthrough complexity by 70%, minimizing thermal leakage and mechanical stress.

  ✅ ️Problem Solved

  In a German materials lab using a 4-zone tube furnace, switching from four single-bore tubes to one 4-bore alumina tube reduced wall penetrations from 4 to 1, cutting installation time by 50% and improving thermal uniformity by 12°C across zones. This upgrade enabled more accurate sintering profiles and reduced sensor failure rate by 30% over 6 months of continuous operation.

• Sensor Housing in Analytical Instruments

  ✅Key Advantages

  1.Channel-to-channel electrical isolation
  ≥10⁶ Ω·cm resistivity between bores ensures signal integrity in multi-sensor configurations.

  2. Compact multi-sensor integration
  Supports up to 6 isolated sensor wires in a single 10mm OD tube, reducing housing footprint by 40%.

  3. Cross-talk suppression in high-sensitivity systems
  Bore wall thickness ≥1.2mm minimizes electromagnetic interference between adjacent signal lines.

  ✅ ️Problem Solved

  In a U.S.-based environmental monitoring system, replacing three separate alumina tubes with one 6-bore tube enabled integration of six optical sensors in a 12mm OD housing. This reduced enclosure size by 35%, eliminated internal cross-talk issues, and improved the signal-to-noise ratio by 18% in field tests over a 3-month deployment in high-humidity conditions.

• Electrical Insulation in High-Voltage Systems

  ✅Key Advantages

  1. Independent conductor isolation in compact form
  Up to 6 conductors can be routed in a single 14mm OD tube with ≥2mm wall separation between bores.

  2. High dielectric strength across bore walls
  Withstands >15 kV/mm between adjacent channels, preventing arc-over in RF and HV systems.

  3. Reduced parasitic capacitance in signal routing
  Bore-to-bore spacing and alumina permittivity (εr ≈ 9.8) minimize capacitive coupling in MHz–GHz ranges.

  ✅ ️Problem Solved

  In a South Korean RF plasma generator project, switching from three single-channel insulators to one 3-bore alumina tube reduced internal wiring volume by 45% and eliminated arc-over events at 12 kV. The redesign improved system uptime by 22% over a 4-month production cycle and enabled safer integration of high-frequency signal and power lines within a single ceramic housing.

Multi-Bore Alumina Tube Usage Instructions

• Install & Operating Conditions

  1. Installation

  a. Insert thermocouple wires, gas lines, or sensor elements into each bore carefully.
  b. Ensure the inserted components match the bore diameter to avoid internal stress.
  c. Use ceramic holders or clamps to secure the tube in place within the equipment.
  d. Avoid applying mechanical force directly to the tube ends during installation.

  2. Operating Conditions

  a. Gradually heat the tube to avoid thermal shock; recommended ramp rate: ≤5°C/min.
  b. Do not exceed the maximum continuous operating temperature of 1450 °C- 1650°C（96%-99.7%）.
  c. Avoid direct flame contact unless specifically designed for burner environments.
  d. Ensure the tube is not exposed to rapid temperature fluctuations (>300°C/min).

  3. Compatibility Check

  a. Suitable for use in vacuum, inert gas, oxidizing, and mildly reducing atmospheres.
  b. Compatible with most acids and alkalis in gaseous form at high temperatures.
  c. Not recommended for use with molten alkali metals or hydrofluoric acid.

• Clean & Maintain

  1. Cleaning

  a. Use compressed air to remove dust or loose particles from the bores.
  b. For internal cleaning, use a soft brush or ultrasonic cleaner with deionized water.
  c. Avoid using strong acids or bases unless confirmed safe for alumina.
  d. Dry thoroughly before reuse to prevent thermal cracking.

  2. Inspection

  a. Regularly inspect for micro-cracks, especially near the ends and bore openings.
  b. Replace tubes showing signs of wear, chipping, or deformation.
  c. Check bore alignment and diameter if used in precision applications.

• Store

  a. Store in a clean, dry, and vibration-free environment.
  b. Avoid stacking tubes directly on each other; use foam or soft separators.
  c. Keep away from corrosive chemicals or moisture to prevent surface degradation.
  d. Label and organize by size and bore configuration to avoid mix-ups.

• Common Misuse of Solutions

  Issue: Cracks appear after the first use
  → Cause: Thermal shock due to rapid heating
  → Solution: Preheat gradually at ≤200°C/hour up to 800°C, then increase rate

  Issue: Bore blockage or contamination
  → Cause: Residue buildup from previous use
  → Solution: Use ultrasonic cleaning or soft mechanical cleaning tools

  Issue: Misfit with equipment
  → Cause: Dimensional mismatch
  → Solution: Confirm tolerance requirements before ordering; request drawing support

Alumina Multi-Hole Ceramic Tubes FAQ

1. Q: Can I customize the inner bore layout or spacing?
   A: Yes. ADCERAX supports client drawings or CAD file definition of bore layout, spacing, and concentricity.
2. Q: Do the tubes maintain insulation when exposed to hydrogen or aggressive gases?
   A: Yes. The dielectric properties of 99.7% alumina remain high even under reducing and corrosive atmospheres.
3. Q: Is it possible to get closed-ended tubes with four bores?
   A: Yes. Closed-end is supported for 2-10 or more bores variants via slip casting or CNC trimming.
4. Q: What surface finish options do you offer?
   A: As-fired (raw), matte-polished, or smooth-blasted surfaces per application need.
5. Q: What’s the dielectric strength of your alumina material?
   A: ≥ 10⁶ Ohm·cm volume resistivity at 25°C; Zero porosity and arc-resistant.
6. Q: Can I get a sample before a bulk order?
   A: Yes, sample orders are accepted for evaluation.
7. Q: What is the tolerance on bore diameter?
   A: Typical tolerance is ±0.1mm（＜100mm）; tighter tolerances can be discussed.

What People Are Saying: Multi-Bore Alumina Tube

• ⭐️⭐️⭐️⭐️⭐️
  “We use ADCERAX’s multi-bore alumina tubes in our gas analysis systems. The dimensional precision is excellent.”
  — Dr. Michael Lang, R&D Director, ThermoTech Instruments, Germany
• ⭐️⭐️⭐️⭐️⭐️
  “The custom 6-hole tubes we ordered fit perfectly into our heating modules. No cracking even after 1000 cycles.”
  — Emily Chen, Procurement Manager, HeatFlow Systems, USA

• ⭐️⭐️⭐️⭐️⭐️
  “We needed a closed-end, polished alumina tube for a high-temperature sensor. ADCERAX delivered exactly as specified.”
  — Hiroshi Tanaka, Senior Engineer, Kyoto Analytical, Japan
• ⭐️⭐️⭐️⭐️⭐️
  “Reliable supplier for our lab equipment components. Fast response and consistent quality.”
  — Pierre Dubois, Technical Buyer, LabEquip France