Fused Silica Quartz Tube: The Complete Sourcing, Thermal-Stress & Engineering Guide for Global Buyers

Our fused silica quartz tubes are rated for continuous service at 1100°C and short-term thermal cycles up to 1450°C. The softening point is approximately 1683°C, with an annealing point around 1140°C. Thanks to an extremely low CTE of 5.5 × 10⁻⁷ /°C, a standard fused silica tube can be heated to 1100°C and immediately dropped into ice water without structural failure or cracking. For high-vacuum furnace work, we advise limiting continuous cycles to 1050°C to prevent mechanical tube deformation caused by atmospheric differential pressure.

Devitrification is the surface conversion of amorphous fused silica into crystalline cristobalite, which usually begins at temperatures above 1150°C in the presence of surface contaminants. To maximize life expectancy: 1) Never handle quartz tubes with bare hands—fingerprint alkali salts (Na, K) act as high-temperature devitrification catalysts; 2) Clean tubes using a 5% to 10% hydrofluoric (HF) acid bath followed by deionized (DI) water wash; and 3) Ensure furnace atmospheres remain free of alkali metal vapors or alkaline fluxes during operation.

Standard clear fused quartz allows broad-spectrum ultraviolet transmission, including the 185 nm short-wave line that converts ambient oxygen (O₂) into toxic ozone (O₃). Ozone-free quartz tubing is doped with trace rare-earth elements (such as titanium or cerium) during the fusion melt. This chemistry completely cuts off wavelengths below 220 nm while allowing maximum transmission of the beneficial 253.7 nm germicidal or UV-curing wavelength, protecting operators and auxiliary rubber/plastic seals from ozone degradation.

Yes. As an authenticated custom manufacturer, over 70% of our production is built strictly to buyer-supplied CAD/PDF drawings. Our capabilities encompass tube slicing, circular lathe grinding, fire-polishing, ultrasonic hole drilling, custom bubble-free welding, domed closed-end sealing, and attaching fused quartz NW/KF flanges, CF knife edges, and quartz ball sockets. We maintain an engineering minimum order quantity (MOQ) of just 1 piece for prototypes.

Lianyungang Vulra Quartz Products Co., Ltd. uses a specialized multi-barrier export packaging system: each tube is cleaned, sealed in a dust-proof PE bag, suspended in customized high-density shock-absorbing EPE foam cutouts, nested inside heavy-ply corrugated cartons, and finally placed in fumigation-free wooden cases reinforced with internal struts. We regularly deliver multi-meter tubes to the USA, Germany, Japan, and worldwide with an intact delivery rate exceeding 99.8%.

To receive an accurate and timely engineering quotation, specify: 1) Outer Diameter (OD), Inner Diameter (ID) or Wall Thickness, and Total Length; 2) Working temperature envelope and whether operating under vacuum or positive pressure; 3) Optical requirements (Clear, Opaque/Milky, or Ozone-free); 4) End finishes (Cut and snapped, ground flat, or fire-polished); and 5) Tolerances required if tighter than standard industrial ±0.1 mm.