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Custom Closed-End Quartz Tube Plug for High-Temperature Sealing-TOQUARTZ®
Key Features of Quartz Tube Plug
TOQUARTZ® quartz tube plugs combine exceptional material properties with precision engineering to deliver reliable performance in demanding laboratory and industrial environments. Our high-purity quartz end caps excel where standard materials fail.
Temperature Resistance
- Softening Point: 1780°C
- Continuous Operating Temperature: 1100°C
- Short-term Peak Tolerance: 1450°C (up to 2 hours)
Chemical Resistance
- Stable in fluoride environments
- Resistant to acids, bases, and corrosive gases
- Corrosion resistance 30x higher than ceramics in acidic environments
Precision Engineering
- Dimensional Tolerance: ±0.2mm standard
- Closed-end thickness: ≥3mm for thermal stability
- Optional hanging loop design for vertical applications
- SiO₂ Content: ≥99.99%
- Trace metal impurities below 10 ppm
- up to 1100°C for continuous operation
Technical Specifications of Fused Quartz Tube Plug
TOQUARTZ® quartz tube plugs and end caps are manufactured to exacting standards to ensure consistent performance in critical applications.
| Parameter | Value/Range | Test Standard |
| Chemical Properties | ||
| SiO₂ Purity | ≥99.99% | ASTM E222-23 |
| Trace Impurities (Fe, Al, K) | <10 ppm | ICP-MS Analysis |
| Physical Properties | ||
| Density | 2.2 g/cm³ | ASTM C693-93 |
| Thermal Expansion Coefficient | 5.5×10⁻⁷/°C (20–300°C) | ASTM E228-22 |
| Thermal Conductivity | 1.4 W/(m·K) | ASTM E1461-22 |
| Max Working Temperature | 1100°C (continuous) | Internal Testing |
| Mechanical Tolerances | ||
| Dimensional Precision | ±0.2mm (standard) | ISO 2768-1 |
| Surface Roughness (Ra) | ≤0.4 µm | ISO 4287:1997 |
TOQUARTZ® Solving Challenges with Quartz Glass Tube Plug
Quartz Tube Plugs for High-Temperature Furnace Applications
Key Advantages
-
Thermal Expansion Matched Sealing
Quartz plug expansion coefficient (5.5×10⁻⁷/°C) matches quartz tubes, preventing seal failure at 1100°C. -
Non-reactive End Cap Surface
No chemical degradation after 100 hours in HCl/H₂SO₄ vapor at 900°C, unlike alumina or stainless steel caps. -
Thermal Shock Resistance Proven
Survives 50+ cycles from 1100°C to 25°C without cracking (ΔT > 1000°C), verified in lab furnace tests.
TOQUARTZ® solution
A German lab equipment OEM reported ceramic end caps cracking after 15–20 thermal cycles, causing 12% test failure rate. After switching to TOQUARTZ® plugs, they achieved 100+ cycles with zero cracking and reduced downtime by 80%. The client also noted improved gas retention and no contamination in high-acid vapor environments. This led to a 3-month extension of component replacement intervals and 18% cost savings.
Quartz Glass Tube Plugs for Vacuum System Sealing
Key Advantages
-
Ultra-Low Outgassing Quartz Composition
<0.01% weight loss at 10⁻⁶ Torr and 800°C over 24h, verified via TGA vacuum test. -
Precision Ground Sealing Surface
Surface roughness ≤0.4 µm Ra ensures helium leak rate <1×10⁻⁹ mbar·L/s in vacuum flanges. -
No Metal Ion Migration
Zero Fe/Cr/Ni ion release under 10⁻⁶ Torr at 1000°C, preventing contamination in plasma systems.
TOQUARTZ® solution
A U.S. university lab using metal-sealed end caps faced 18% vacuum failure rate in plasma reactors. TOQUARTZ® plugs with precision-ground ends reduced leak rate to <1×10⁻⁹ mbar·L/s, verified via helium leak test. Outgassing dropped by 92%, improving vacuum stability and reducing chamber cleaning frequency. The lab extended maintenance intervals from 2 weeks to 6 weeks.
Fused Silica Tube Plugs with Loop for Vertical Suspension Systems
Key Advantages
-
Integrated Monolithic Loop Design
Loop and plug formed from single quartz body, tensile tested to >60 MPa without detachment or fracture. -
Zero Metal Contamination Risk
No metallic components used; eliminates Fe/Ni/Cr particle contamination in high-purity growth chambers. -
Load-Bearing at Elevated Temperatures
Supports 1.5 kg suspended load at 1000°C for 72h without deformation or structural failure.
TOQUARTZ® solution
A Japanese materials institute used metal hooks in vertical furnaces, which deformed at 900°C and caused sample drops. TOQUARTZ® loop-integrated plugs held 1.5 kg loads for 72h at 1000°C with no deformation or fracture. Contamination from metal ions was eliminated, improving crystal growth purity by 15%. The institute standardized TOQUARTZ® plugs across 4 furnace lines, reducing defect rates by 22%.
TOQUARTZ® Custom Fused Silica Tube Plug Services
TOQUARTZ® offers comprehensive customization services for quartz tube plugs to meet your exact specifications. Our engineering team works directly with you to design and manufacture the perfect solution for your application.
Dimensional Customization
- Diameter: 5mm to 150mm
- Wall thickness: 1mm to 8mm
- End cap thickness: 3mm to 15mm
- Loop dimensions: Customizable
Material Options
- Clear fused quartz (standard)
- Opaque/milky quartz for IR applications
- UV-transmitting grades
- High-purity options (up to 99.995% SiO₂)
Custom Design Process
- Initial consultation to understand application requirements
- Technical drawing review or creation by our engineers
- Prototype production for testing (if required)
- Production with comprehensive quality control
- Documentation and technical support
Usage Guidelines for Quartz Tube Plug
Proper handling, installation, and maintenance of quartz tube plugs ensures optimal performance and extends service life. Follow these guidelines to maximize the value of your TOQUARTZ® products.
Handling & Storage
- Wear powder-free gloves when handling to prevent contamination
- Store in original packaging or on clean, soft surfaces to prevent scratches
- Avoid impact or point pressure that could cause microfractures
- Store in a clean, dry environment away from chemical vapors
Installation
- Ensure mating surfaces are clean and free from debris
- For vacuum applications, use appropriate vacuum-rated seals
- Avoid over-tightening or applying uneven pressure
- For high-temperature applications, allow for thermal expansion (0.5% at 1000°C)
Thermal Cycling
- Maximum recommended heating rate: 10°C/minute for thick sections
- For cooling from >800°C, rate should not exceed 15°C/minute
- Allow uniform heating and cooling to prevent thermal stress
- Avoid direct contact with cooling air streams when hot
Cleaning & Maintenance
- Clean with ultrapure water or semiconductor-grade solvents
- For stubborn contaminants, use dilute HF (5%) followed by thorough rinsing
- Inspect regularly for microcracks or surface damage
- Avoid abrasive cleaning materials that can scratch surfaces
Need Engineering Support for Your Quartz Tube Plug Application?
develop a custom solution for your specific requirements.
Contact us today for expert assistance.
Why Partner with TOQUARTZ
Direct Factory Advantage
As a direct manufacturer, we can cut out the numerous intermediate links.
Engineering Expertise
Technical team guides clients from material selection to design optimization, translating specs into deliverables.
Flexible Manufacturing
Handling standard & custom orders via small-batch expertise and prototyping rigor to meet urgent deadlines.
Quality
Assurance
Pre-shipment 3-step validation:
1. dimensional accuracy,
2. material purity ,
3. performance thresholds
Global Supply Chain
Reliable global logistics to industrial hubs (DE/US/JP/KR priority) with trackable milestones.
Releted Products
As a specialized manufacturer with direct factory capabilities, TOQUARTZ provides both standard and custom quartz solutions with engineering support throughout the specification and implementation process.
FAQ
Q: What is the difference between quartz tube plugs and ceramic end caps?
A: Quartz tube plugs offer several advantages over ceramic alternatives:
(1) Higher temperature capability with less deformation,
(2) Lower thermal expansion for better sealing at varying temperatures,
(3) Superior chemical resistance, especially to acids and halogens,
(4) Better thermal shock resistance, reducing cracking during cycling,
(5) Higher purity with fewer contaminants that might affect sensitive processes.
Q: What is the maximum operating temperature for your quartz tube plugs?
A: TOQUARTZ® quartz tube plugs can withstand continuous operation at 1100°C and short-term exposure (up to 2 hours) at temperatures up to 1450°C. The softening point of our high-purity quartz is approximately 1780°C. For applications above 1100°C, we recommend discussing specific requirements with our technical team to ensure proper thickness and design parameters.
Q: Can quartz tube plugs be used with vacuum systems?
A: Yes, TOQUARTZ® quartz tube plugs are suitable for vacuum applications up to 10⁻⁶ Torr. For optimal vacuum sealing, we recommend our precision-ground sealing surfaces (≤0.4 µm Ra) and using appropriate vacuum-compatible gaskets or O-rings. Our high-purity quartz material has minimal outgassing compared to other materials, making it ideal for clean vacuum environments.
Q: What is the difference between transparent and opaque quartz tube plugs?
A: Transparent quartz tube plugs offer excellent UV and visible light transmission (>95%) and are ideal for applications requiring visual monitoring or UV exposure.
Opaque (milky) quartz tube plugs contain microscopic air bubbles that scatter light, resulting in reduced transparency but improved infrared reflection.
Opaque versions are preferred for thermal applications where heat retention is important or where light transmission must be minimized.
Q: How does thermal cycling affect quartz tube plugs?
A: Quartz has excellent thermal shock resistance compared to other materials, but proper thermal cycling protocols extend service life. For optimal performance, we recommend heating rates not exceeding 10°C/minute and cooling rates not exceeding 15°C/minute from temperatures above 800°C. Uniform heating and cooling prevents thermal stress concentration. Our quartz tube plugs typically withstand hundreds of thermal cycles when proper protocols are followed.
Contact our engineering team for technical consultation and pricing. We’ll help you select the optimal specifications for your application requirements.