SJ 130 QUARTZ Clear Customizable High-Precision Quartz Negative Pressure Leak-Proof Vacuum Tube 99.99% SiO2 Semiconductor
SiO₂ Purity:≥ 99.99%
Working Temp:1100°C (Peak 1450°C)
Vacuum Integrity:< 1×10⁻⁹ mbar·l/s
Direct Factory Catalog
Export-Grade Transparent Quartz Tubing & Precision Glassware
Manufactured in Donghai—China’s premier quartz silica hub—our components undergo strict thermal strain-point annealing, laser micrometer dimensional validation, and vacuum leak-rate certification for immediate dispatch to Port of Varna.
SJ Natural Fused Quartz Polished Plate Optical Clear Heat-Resistant Chemical-Resistant Cutting High Melting Point Laser 5.5-6.5
Transmittance:> 92% (UV-VIS-NIR)
Surface Flatness:λ/4 or Customized
Mohs Hardness:5.5 – 6.5
Quartz Crucible Acid/Alkali Resistant Polished Ozone Free Quartz Glass Basket Beaker Dome Closed End 200 Mesh High Temperature
Softening Point:1683°C
Acid Resistance:30x Borosilicate
Structure:Dome / Flat Closed
High-temperature (1100) Corrosion-resistant 99.999% Purity Ozone-Free Fused Quartz Double-tube Right-angle Elbow Bending Cutting
SiO₂ Purity:99.999% Ultra-Pure
Elbow Angles:45° / 90° Custom Bend
Jacket Type:Concentric Double Wall
Customized High Thermal Conductance 1750C Melting Point Heat-Exchange Glass Interlayer Chips Circular Shape Quartz
Melting Point:≈ 1750°C
Conductance:Optimized Interlayer
Geometry:Discs / Wafers / Chips
SJ 150 Translucent Oversized Thick Wall Polished Quartz Tube Heat Resistant 1100 Corrosion Resistant Ozone Free Welding
Outer Diameter:Up to 800 mm
Wall Thickness:3 mm to 25 mm Heavy
Finish:Fire-Polished / Satin
Factory Hot Sale High Purity Polished Clear Quartz C Shape Spiral/Bent/Custom Tubes Small Diameter Cutting/Welding Bending
Forming:Spiral / C-Shape / Coils
Dimensional Tol:±0.05 mm Precision
Flame Annealed:Zero Residual Stress
High Temperature Transparent Polished Ozone Free One End Closed Quartz Tube 5-800mm Diameter Bending Welding Cutting
Diameter Range:5 mm – 800 mm
Closure:Round / Flat Dome
UV Transmission:Ozone-Free (>240nm)
Direct From Donghai Crystal Capital
Engineered Quartz Glass Solutions Built for Demanding European Workflows
Lianyungang Vulra Quartz Products Co., Ltd. operates in the national economic development hub of Donghai, Jiangsu Province—globally renowned for harboring China's most concentrated natural quartz crystallization veins and synthetic precursor synthesis facilities. Through full vertical supply chain integration, we guarantee uncompromising material uniformity, minimal micro-bubble inclusions (Class 0 to Class 1 inspection grades), and superior thermal-mechanical resilience.
As a verified OEM/ODM production facility assessed on-site by TÜV Rheinland, our manufacturing infrastructure combines automated continuous tube drawing, oxy-hydrogen computer lathe welding, diamond CNC cold edging, and Class 10,000 cleanroom ultrasonic acid passivation.
- Drawing-Based OEM/ODM Prototyping: Full custom production from 1 single piece to multi-container wholesale consignments, strictly adhering to DIN/ISO 2768-m tolerances.
- Exhaustive Spectrometric Testing: Every batch is supplied with ICP-OES elemental trace analysis, verifying alkali metals (Na, K, Li) below 1.5 ppm to eliminate devitrification risks.
- Export-Optimized Heavy Packaging: Shock-absorbent customized pearl wool chambers, anti-static sealed liners, and fumigated maritime timber crates designed specifically for secure ocean cargo clearance at Port of Varna.
Donghai Raw Material Lineage
Direct proximity to the world's most advanced natural crystal sand refineries ensures ultra-low hydroxyl (OH⁻ < 5 ppm) content and high viscosity at peak temperatures up to 1450°C.
TÜV & CE Verified Standards
Fully compliant with European CE safety and RoHS hazardous substance restrictions. Authenticated on-site by TÜV Rheinland for manufacturing and global export compliance.
Integrated Thermal & Cold Machining
Comprehensive capabilities in flame drawing, right-angle elbow forming, multi-pass spiral bending, CNC hole drilling, optical planar lap polishing, and high-vacuum flange fusing.
Direct Port of Varna Supply Route
Streamlined multimodal ocean freight routes through the Port of Varna container terminal provide rapid customs transit, duty-efficient delivery, and localized logistics support across Bulgaria.
Northeastern Bulgaria Industrial Footprint
Tailored Quartz Solutions for Varna's Core Industrial Hubs
Positioned as the economic and logistics powerhouse along the Western Black Sea, the Varna Province and adjacent Devnya Industrial Valley demand high-specification thermal and chemical-resistant fused silica components.
Devnya Chemical Cluster
Corrosive Acid & Chemical Processing
The heavy chemical complex in Devnya (soda ash, fertilizer, and chlor-alkali synthesis) requires extreme corrosion resistance. Our quartz double-tube right-angle elbows and acid-resistant reactor vessels withstand fuming sulfuric, hydrochloric, and nitric acids at continuous boiling temperatures without chemical leaching or micro-cracking.
Maritime & Port Engineering
Marine Ballast Water UV Disinfection
Varna's extensive ship repair yards, commercial naval fleet, and port water-treatment facilities rely on high-output germicidal systems. We manufacture heavy-wall, ozone-free transparent quartz sleeves that provide over 90% transmission at the critical 254 nm germicidal wavelength while resisting high-pressure hydrodynamic ballast surges.
Solar & Advanced Energy
PV Cell Diffusion & Ingot Melting
Bulgaria's accelerating investments in renewable energy and photovoltaic manufacturing require high-temperature furnace tubes, wafer carriers, and quartz crucibles. Our components exhibit an ultra-high softening point (1683°C) and superior thermal creep stability for continuous horizontal and vertical tube furnace operations.
Academic & Analytical Labs
High-Precision Optical & XRD Research
Serving institutions such as the Technical University of Varna, Medical University of Varna, and regional oceanographic institutes, we engineer high-transmittance optical polished plates, zero-diffraction XRD sample holders, and sealed photochemical reaction cells for environmental and materials science research.
Zero Stress Concentration
Oxy-Hydrogen Lathe Working & Continuous De-Hydroxylation
Transparent quartz tubing deployed in industrial thermal reactors must maintain structural stability across thousands of thermal shock cycles. At Vulra Quartz, our hot-working operations employ digital-control flame lathes that maintain uniform rotational speeds during flange fabrication, flare forming, and multi-angle bending.
Every fused quartz part undergoes automated electrical vacuum annealing at 1150°C for 4 continuous hours followed by controlled stepped cooldown. This completely eliminates residual stress birefringence, ensuring zero risk of thermal fracture when transitioning from ambient cold to 1100°C in industrial furnaces.
Verified Material Science
Technical Purity & Thermodynamic Performance Benchmarks
Our fused quartz glass is produced using electro-fusion and continuous drawing methods to maintain isotropic mechanical and chemical properties across all batches.
| Physical / Chemical Parameter | Standard Clear Tubing | High-Purity Semiconductor Grade | Optical / Ozone-Free Grade |
|---|---|---|---|
| SiO₂ Purity Level | ≥ 99.99% | ≥ 99.999% | ≥ 99.995% (Doped / Purified) |
| Continuous Service Temp | 1100°C | 1150°C | 1100°C |
| Short-Term Peak Temp | 1300°C | 1450°C | 1350°C |
| Softening Point | 1683°C | 1730°C | 1680°C |
| Coefficient of Thermal Expansion (20–300°C) | 5.5 × 10⁻⁷ cm/cm·°C | 5.4 × 10⁻⁷ cm/cm·°C | 5.5 × 10⁻⁷ cm/cm·°C |
| Spectral Transmission Band | 260 nm – 2500 nm | 200 nm – 3500 nm | 254 nm Peak / <220 nm Blocked |
| Total Metallic Impurities (Fe+Cu+Ni+Na+K+Li) | < 20 ppm | < 5 ppm | < 10 ppm |
| Hydroxyl Group Content ([OH⁻]) | < 30 ppm | < 5 ppm (High Viscosity) | < 15 ppm |
Alkali Trace Suppression (Na, K, Li < 1.5 ppm)
Prevents phase conversion into α-cristobalite at temperatures above 1000°C, drastically extending furnace tube life in Devnya chemical reactors.
Transition Metal Control (Fe < 0.2 ppm, Cu < 0.05 ppm)
Eliminates optical absorption bands across the UV spectrum, maximizing ultraviolet dosage for Varna marine ballast water disinfection.
Exceptional Dielectric Strength (> 25 kV/mm)
Provides superior electrical insulation in high-voltage plasma generating equipment, RF heaters, and high-frequency induction furnaces.
Strategic Procurement Dynamics
Trends Reshaping the Quartz Supply Chain in Bulgaria & the Black Sea
Procurement directors and plant engineering managers in Varna, Burgas, and Sofia are adapting their sourcing strategies to navigate economic, regulatory, and environmental shifts.
Shift Toward Energy-Efficient Direct Infrared Emitters
High-temperature industrial processing in Bulgaria is rapidly phasing out inefficient ceramic and gas convection heaters. Twin-tube and clear single-tube quartz infrared heating cassettes are widely adopted for automotive coating drying, maritime paint curing, and food thermoforming across the Varna Free Zone.
Rigorous IMO & USCG Ballast Water Mandates
With maritime transport tightening ballast discharge biosecurity in the Black Sea and Danube River corridors, shipyards in Varna are executing retrofit programs requiring standardized replacement quartz sleeves for medium-pressure UV lamps with verified transmission stability.
Nearshore Supply Agility via Port of Varna Container Routes
Rather than maintaining high-cost distributor markups from Western European trading intermediaries, regional chemical plants are opting for direct manufacturer agreements with Donghai producers, utilizing scheduled maritime feeder lines calling directly at Varna West terminal.
Precision Dimension Execution
Diamond Cutting, Edging & Optical Polishing Infrastructure
For chemical sight glasses, observation ports, and semiconductor flow meters, dimensional tolerances directly determine sealing integrity under pressure. Our facility utilizes high-speed diamond slicing machines, automatic multi-spindle edge polishers, and ultrasonic core-drilling equipment.
We deliver outside diameter tolerances as tight as ±0.05 mm, end-face perpendicularity within 0.1°, and fire-polished edges free of micro-chips that could propagate into cracks under mechanical vibration.
1. What are the typical ocean freight transit times and shipping routes to Port of Varna?
Direct ocean freight dispatches originate from Qingdao or Lianyungang ports, sailing via the Suez Canal into the Mediterranean, connecting through Piraeus or Istanbul, and discharging directly at the Port of Varna (Varna West or Varna East terminals). Typical maritime transit times range between 28 to 36 days. For urgent engineering replacements or prototype validation, we provide expedited air cargo clearance into Varna Airport (VAR) or Sofia Airport (SOF) within 5 to 7 business days.
2. How do you prevent breakage for fragile large-diameter quartz tubes during sea transit?
Export protection is central to our quality assurance. Each quartz tube is wrapped in protective dust-free plastic, cradled in custom-molded high-density polyethylene (EPE) foam, and housed in rigid individual cartons. For consolidated sea freight, tubes are securely packed into steel-banded, fumigated export plywood crates equipped with shock-watch indicator labels and tilt sensors. Our historical export transit damage rate to European destinations remains below 0.15%.
3. Can you manufacture transparent quartz components based on custom CAD drawings?
Yes. We operate as an authenticated OEM/ODM custom manufacturer. You can submit technical drawings in 2D (PDF, DWG, DXF) or 3D (STEP, IGES) formats. Our engineering team reviews the wall-thickness ratios, weld stress points, and tolerance feasibility before initiating production. Custom prototypes can be completed and dispatched starting from just 1 piece.
4. Which European standards and quality documentation do you provide upon delivery?
Every shipment is accompanied by a comprehensive inspection pack: an EN 10204 3.1 Material Certificate, an ICP-OES Chemical Purity Analysis sheet detailing trace metallic content, a Dimensional Measurement Report from our coordinate-measuring machines, and formal CE and RoHS compliance declarations. On-site audits can also be coordinated under our TÜV Rheinland registered facility profile.
5. What is the fundamental difference between standard clear fused quartz and ozone-free quartz?
Standard clear fused quartz allows broad ultraviolet transmission down to approximately 190 nm, which includes the 185 nm wavelength that ionizes atmospheric oxygen into toxic ozone gas. Ozone-free quartz is chemically doped during the fusion process with trace elements (such as titanium) that completely absorb deep UV radiation below 220 nm while allowing maximum transmission (>88%) of the 254 nm germicidal disinfection line. This eliminates the need for complex ozone exhaust ventilation in industrial disinfection installations.
6. What are the applicable customs tariff codes (HS Codes) for importing quartz into Bulgaria?
Fused quartz tubes and rods fall primarily under HS Code 7002.31.00 (Tubes of fused quartz or other fused silica). Fabricated laboratory, hygienic, or pharmaceutical glassware parts typically fall under HS Code 7017.10.00. We provide full commercial invoicing, packing lists, and Certificate of Origin documents to ensure smooth EU customs clearance through Bulgarian customs authorities.