Alumina thermocouple protection tubes
热电偶保护管 · 刚玉保护管
One-end-closed and open-ended ceramic sheaths that protect thermocouples in temperature-measurement instruments and industrial furnaces.
- One-end closed
- Open-ended
- Round
- Elliptical
Manufacturer · Tangshan, China
Alumina protection tubes and insulators, direct from the manufacturer.
High-alumina and corundum tubes, multi-bore insulators, furnace tubes, crucibles and custom parts, in standard sizes or made to your drawing.
Key facts
- Certified quality system, scope: thermocouple protection tubes
- ISO 9001:2015
- Lab-tested alumina tube sample, report 26-04928
- 99.61% Al₂O₃
- Standard sizes usually ship from stock (small orders to bulk)
- ~3–7 days
- Custom parts made to drawing, usual minimum order
- 100 pcs
- Samples for approval before the order runs
- 5–10 pcs
Products
Five product families for sensor, furnace and laboratory buyers.
Protection tubes lead the range. The same materials and forming lines make the insulators, furnace tubes, crucibles and special-shaped parts that go around them.
Alumina thermocouple insulators and multi-bore tubes
绝缘管 · 热电偶绝缘瓷管
Single-, double- and multi-bore insulators that separate thermocouple wires and provide electrical insulation at high temperature and high frequency.
- Single bore
- Double bore
- Multi-bore
- Round
- Elliptical
- Capillary
High-temperature alumina and corundum furnace tubes
高温炉管 · 刚玉通管 · 高温炉件
Open-ended process tubes, large-diameter tubes and custom tubes for laboratory, resistance, electric and heat-treatment furnaces.
- Open-ended process tube
- Large-diameter tube
- Custom tube
Alumina and corundum crucibles and boats
氧化铝坩埚 · 刚玉坩埚 · 刚玉方舟
Cylindrical, rectangular and special-shaped crucibles and boats for metallurgy, chemical processing, electronics, glass and laboratory analysis.
- Cylindrical
- Rectangular
- Special-shaped
Custom alumina and industrial ceramic components
异型瓷件 · 刚玉异型瓷件 · 工业陶瓷
Special-shaped parts made from your drawing or sample, by slip casting, pressing, extrusion or hot pressing.
- Made to drawing
- Made to sample
- Special-shaped parts
- Pressed and extruded oxide components
Also made
- Alumina, corundum, and industrial ceramic tubing
- Chemical and laboratory porcelain components
- Ceramic balls, jars, and related mill components
- Textile wear and friction ceramics
- Electrical, heating, and lamp-base ceramics
- Ceramic rollers and screening components
Who we supply
Made for instrument makers, furnace builders and industrial plants.
01
Thermocouple and temperature-instrument makers
Protection tubes and multi-bore insulators
02
Electric, vacuum and sintering furnace builders
Tubes and parts made to their drawings
03
Steel and industrial plants
Open-ended corundum tubes and custom parts
How we make it
From alumina powder to a packed crate, in one factory.
Milling, forming, firing, finishing, inspection and packing all happen in our own factory in Tangshan.
02Milling
The powder is milled in large drum ball mills.
05Firing
Tubes hang vertically in the kiln, and our written gas-kiln procedure controls firing with thermocouples and an optical pyrometer.
06Finishing
Tubes are cut to the ordered length, then slotted or drilled where the drawing calls for it.
07Inspection
Outside and inside diameters are measured with vernier calipers.
Made to your drawing
Send the drawing you already have. We form the part to it.
We design from customer drawings or samples, and make special-shaped parts by four forming routes. Tell us the dimensions and operating conditions; we propose the material and route.
Forming methods
- Slip casting
- Pressing
- Extrusion
- Hot pressing
Geometries
- Round tube
- Elliptical tube
- Square tube
- Open-ended through tube
- One-end-closed protection tube
- Single-bore tube
- Double-bore tube
- Multi-bore tube
- Capillary tube
- Perforated tube
- Threaded tube
- Ribbed or prismatic tube
- Solid rod
- Crucible
- Boat
- Ball
- Custom-shaped component
Certified and tested
ISO 9001 certified for protection tubes, and tested by an independent lab.
Our quality management system is certified to ISO 9001:2015 for making ceramic protection tubes for thermocouples. An alumina tube sample tested at 99.61% Al₂O₃.
Quality management
ISO 9001:2015
GB/T19001-2016 · certified by CFL Certification Center (中物联认证中心)
- Scope
- Manufacturing of ceramic protective tubes for thermocouples
- Registration
- 06525Q02034R1S
- Valid
- 6 August 2025 – 5 August 2028
- Accreditation
- CNAS C065-M · IAF
A copy of the certificate is available on request.
Independent lab test
99.61% Al₂O₃
Alumina tube sample, tested by Chinalco Testing Technology (Zhengzhou) Co., Ltd., 13 May 2026. Report 26-04928.
| Item | % | Method |
|---|---|---|
| Al₂O₃ | 99.61 | GB/T 24487-2022 |
| SiO₂ | 0.15 | GB/T 6609.3-2004 |
| Fe₂O₃ | 0.014 | GB/T 6609.4-2004 |
| Na₂O | 0.054 | GB/T 6609.1-2018 |
| CaO | 0.13 | GB/T 6609.1-2018 |
| Loss on ignition | 0.033 | GB/T 6609.2-2022 |
Result for the submitted sample. Each quotation comes with test data for the grade you order.
Track record
Our protection tubes went into China’s solar manufacturing expansion.
As China built out its solar-panel manufacturing capacity, the factory supplied that expansion with thermocouple protection tubes for temperature measurement, at industrial scale.
The tubes we offer to export buyers come from the same long-running product line, made in the same factory in Tangshan.
- Product
- Thermocouple protection tubes
- Use
- Temperature measurement
- Market
- China’s solar-panel manufacturing build-out
Packing
Crated, strapped and palletised before it leaves the factory.
- 01Foam-lined plywood crates on skids, strapped
- 02Tubes bubble-wrapped or bundled in stretch film
- 03Small insulators in 1 kg bags
- 04Numbered crates strapped on pallets
Tell us your destination and handling needs; we confirm packing and marking per order.
Request a quote
Send us a drawing, a sample or a part number.
Tell us the dimensions, grade and quantity. A contractual datasheet with current, product-specific test data and tolerances comes with each quotation.
- Custom parts, usually from
- 100 pcs
- Samples for approval
- 5–10 pcs
- Production, usually
- 25–30 days
- Standard sizes from stock, small to bulk orders
- ~3–7 days