High Purity Fused Silica Quartz U-Tubes: Thermal, Chemical & Optical Performance for Lab, Semiconductor -sara
Published On: July 17, 2026
Quartz U-tube, also known as U-shaped fused silica bent tube, is processed from 99.99% high-purity fused silica raw material via precision hot bending, annealing and flame polishing. The unique U-loop structure saves equipment layout space, realizes closed circulation of gas/liquid medium, and becomes the core flow channel component for laboratories, semiconductor, photovoltaic, fine chemical and optical industries.
1. Core Performance Parameters of Quartz U-Tubes
1.1 Ultra High Thermal Stability (Core Advantage)
- Long-term continuous working temperature: 1100℃–1200℃; instant short-time temperature resistance up to 1350℃
- Ultra-low thermal expansion coefficient: 5.5×10⁻⁷/℃, only 1/20 of ordinary glass
- Outstanding thermal shock resistance: No crack or deformation under rapid heating & cooling cycles (from room temperature to 1000℃ quenching test pass)
- Uniform heat conduction: Symmetrical U double-arm design realizes balanced temperature field, suitable for heating circulation, catalytic reaction furnace pipeline
1.2 Superior Chemical Inertness & Corrosion Resistance
SiO₂ purity ≥99.99%, total metal impurity content ≤25ppm:
- Resistant to all strong acids (sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid) and organic solvents at high temperature
- 150 times better acid resistance than stainless steel, 30 times higher corrosion stability than borosilicate glass
- No ion precipitation, zero contamination to high-purity gas, wafer and chemical reagent
- Only hydrofluoric acid (HF) and hot concentrated strong alkali will slightly corrode the surface
1.3 Excellent Optical Transmission Performance
- Transparent quartz U-tube: Visible light transmittance >93%, UV band transmittance 80%–90%, widely used for UV photocatalysis, spectral observation, reflux visual monitoring
- Opaque milky white quartz U-tube: Uniform infrared radiation, stray light suppression, applied to crystal growth, infrared heating furnace
- Flame-polished inner & outer wall, no bubble, scratch or haze, stable light transmission without attenuation after long-term high temperature operation
1.4 Mechanical & Custom Processing Performance
- Post hot-bending annealing eliminates internal stress, bending strength increased by 30%, anti-vibration, pressure fluctuation resistant
- Full customized support: Custom outer diameter, wall thickness, U arc radius, arm length, side branch ports, flanged joints
- Multiple sealing options: Integral flange, frosted mouth, PTFE quick connector, metal welding transition end
- Strict dimensional tolerance: Arc bending error ±0.2mm, flatness & roughness controlled for high-precision equipment matching
2. Main Industrial Application Scenarios
- Laboratory Scientific Research
UV photocatalytic reactor, gas drying absorption tube, distillation reflux observation loop, high-temperature digestion experiment pipeline, chloride ion detection equipment
- Semiconductor & Photovoltaic Manufacturing
Diffusion furnace gas circulation pipeline, chip packaging exhaust channel, wet cleaning medium flow tube, silicon wafer high-temperature reaction carrier
- Fine Chemical & Pharmaceutical Industry
Corrosive acid distillation equipment, reaction kettle cooling circulation tube, high-purity reagent purification monitoring sight loop
- Optical & Thermal Equipment
Infrared heating furnace tube, UV sterilization flow channel, photonic crystal wafer production temperature control pipeline
