Laboratory · Research · Industrial Analysis
Quartz Glass Engineered for Laboratory Demands
Laboratory environments impose conditions that conventional materials cannot withstand — including high furnace temperatures, aggressive chemical exposure, rapid thermal cycling, and strict contamination control. FGQuartz has manufactured high-purity laboratory quartz glass equipment for research institutions, industrial laboratories, and analytical facilities worldwide since 2005.
Est. 2005
Lianyungang, Jiangsu, China
Global Shipping
80+ countries served
Custom Fabrication
Any geometry, any volume
Stock Items
Common sizes ship fast
OEM & Research
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Product Range
Laboratory Quartz Glass Equipment
FGQuartz manufactures the complete range of laboratory quartz glass equipment required for high-temperature processing, trace-level chemical analysis, and photochemical research. Standard items ship from stock; custom vessels are produced to specification from the same facility in Lianyungang.
Quartz Crucibles
The quartz crucible is the most fundamental piece of high-temperature laboratory glassware — the vessel in which samples are ashed, fused, or calcined at temperatures that would destroy any other common glassware. FGQuartz crucibles are manufactured from high-purity fused silica by CNC turning and hand finishing to ensure wall thickness uniformity and a flat, stable base. Low-form crucibles with wide, shallow profiles are used for gravimetric analysis and ashing; tall-form crucibles are used for fusion work with alkali fluxes such as sodium carbonate, potassium pyrosulphate, and lithium tetraborate. Both lipped and plain-rim styles are available across a wide range of volumes from micro-scale up to laboratory production capacity. Fitted lids are available to reduce volatilisation losses during high-temperature ignition.
Combustion & Evaporation Boats
Combustion boats hold solid samples in the high-temperature zones of tube furnaces for elemental analysis by combustion — CHNS analysis, oxygen combustion flask methods, and carbon-sulphur determinations. The boat must survive repeated cycling through the highest-temperature zone of the furnace without warping, cracking, or contaminating the combustion gases with interfering elements. FGQuartz combustion boats are manufactured from dense fused silica without additives. Evaporation boats serve the related function in evaporation and sintering applications — holding powders, films, or solutions for controlled thermal treatment on hot plates or in open-tube furnaces. Custom boat lengths and widths are produced to fit specific furnace tube internal diameters.
Evaporation Dishes & Watch Glasses
Evaporation dishes are flat-bottomed shallow vessels used for concentrating solutions, drying precipitates, and performing open-air digestions on hot plates. Their shallow geometry maximises surface area to volume ratio, accelerating evaporation. In trace element analysis, the choice of dish material directly determines the background contamination level — borosilicate glass leaches boron and alkali metals into the digest, which interfere with ICP-MS and ICP-OES determinations. FGQuartz evaporation dishes in fused silica provide a negligible boron and alkali blank, making them the correct choice for ultra-trace analysis of these elements. Quartz watch glasses serve as covers for crucibles and dishes during digestion, and as weighing vessels for hygroscopic materials.
Reaction Tubes & Combustion Tubes
Tubular quartz reaction vessels are the workhorses of high-temperature gas-phase chemistry, materials synthesis, and analytical combustion. A combustion tube inserted into a horizontal tube furnace provides the controlled high-temperature environment needed for organic combustion, catalyst testing, chemical vapour deposition experiments, and gas-solid reactions. FGQuartz produces reaction tubes in open-ended and closed-end configurations, with and without ground glass joints or flanged ends for connection to gas manifolds and vacuum systems. The range includes narrow-bore tubes for micro-reaction work, wide-bore process tubes for larger sample batches, and U-tube geometries for specific gas-handling applications. All tubes are manufactured from clear fused silica for visual observation of the sample or reaction zone.
Beakers, Flasks & Round-Bottom Flasks
The standard forms of laboratory glassware — beakers, Erlenmeyer flasks, and round-bottom flasks — are available from FGQuartz in fused silica for applications where borosilicate glass is inadequate. The most common reasons for upgrading to quartz forms are operating temperature above the borosilicate working range, the requirement for UV transparency to support photochemical reactions, or the need for an ultra-low trace metal background in the vessel wall for high-sensitivity analytical work. Quartz round-bottom flasks are used in UV-assisted synthesis, photocatalysis studies, and reactions requiring immersion in high-temperature oil or salt baths that exceed the limits of borosilicate. Custom flask geometries with specific neck sizes, ground joint standards, or integrated features such as side arms and frits are produced to drawing.
Distillation & Reflux Glassware
Distillation of high-boiling liquids, strongly acidic mixtures, or reactive organics often requires the thermal resistance and chemical inertness of quartz rather than borosilicate glass. FGQuartz produces quartz distillation heads, condensers, receiving flasks, and column sections for both atmospheric and vacuum distillation rigs. Quartz condensers are used specifically in acid digestion systems where the condensed vapours are highly corrosive — perchloric acid fume hoods, sub-boiling acid stills for ultra-pure reagent production, and Kjeldahl digestion units. Sub-boiling quartz stills are used by analytical laboratories to produce ultra-pure HNO₃, HCl, and HF at purity levels that commercial reagent-grade acids cannot achieve, providing a homemade reagent blank orders of magnitude lower than commercial alternatives.
ICP Plasma Torch Assemblies
The ICP plasma torch is the heart of ICP-OES and ICP-MS instruments — the component through which the argon plasma burns at temperatures exceeding 6000 K, and through which the sample aerosol is introduced for atomisation and excitation. The torch is a triple-concentric-tube quartz assembly: an outer tube, an intermediate tube, and an inner injector tube. All three must withstand the extreme thermal gradient between the plasma zone at the top and the cooler base where the tubes connect to the gas manifolds. FGQuartz manufactures replacement torch assemblies and individual torch tubes compatible with major ICP instrument platforms from Perkin-Elmer, Agilent, Thermo Scientific, Horiba, and others. Mini-torch designs for low-flow argon operation and demountable torch systems are also available.
Tube Furnace Liners & Process Tubes
Tube furnace liners protect the ceramic heating elements from chemical attack by sample vapours, and provide a clean, chemically inert process zone for high-temperature treatments. Quartz liners are removed and cleaned or replaced at intervals far less disruptive and costly than replacing the furnace itself. FGQuartz supplies single-zone and multi-zone furnace liners in clear and opaque fused silica grades, matched to the internal diameter of major tube furnace platforms. Opaque quartz liners with low thermal emissivity are used as secondary containment and thermal shielding in furnaces where the sample tube requires additional protection from radiant heat. Custom lengths, diameters, and end configurations are produced to match specific furnace models.
Custom Laboratory Quartz Vessels
Research laboratories constantly generate requirements for quartz vessels that do not exist in any catalogue — a photoreactor with a specific geometry for maximum UV illumination uniformity, a custom digestion vessel with integrated cooling jacket, a high-pressure reaction tube with metal-sealing flanges, or a gas sampling cell with defined optical path length and specific port geometry. FGQuartz produces all of these through a combination of CNC machining, oxy-hydrogen flame welding, and precision grinding. Customers supply drawings in DXF, STEP, or IGES format, or sketch the required geometry for the engineering team to interpret and draft. Prototype quantities from a single piece are accepted with no minimum order, and repeat production follows the same programme without re-qualification.
Laboratory Applications
Quartz Glass Across Every Laboratory Discipline
Select a laboratory discipline to explore the specific role quartz glass plays, why it outperforms alternatives in that environment, and what FGQuartz supplies into that field.
ICP-MS · ICP-OES · AAS · GFAAS · TXRF
Trace Element Analysis & Ultra-Trace Geochemistry
Trace element analysis at the parts-per-billion and parts-per-trillion level is one of the most demanding analytical disciplines in terms of contamination control. Every piece of labware that contacts the sample before it reaches the instrument detector is a potential source of contamination — and the choice of vessel material is often the dominant variable determining the analytical blank level. Borosilicate glass is essentially unusable for trace boron analysis because the glass itself is the primary boron source. It is also a significant source of sodium, potassium, calcium, and aluminium, which interfere with ICP determinations of these elements at low concentrations.
Fused silica is the cleanest glass-based vessel material available for ultra-trace analysis. The SiO₂ matrix leaches only silicon — a ubiquitous element that is rarely the target analyte and whose contribution is well-characterised. For trace analysis of all other elements, a quartz vessel presents a dramatically lower contamination blank than any alternative glassware, enabling method detection limits an order of magnitude lower than those achievable in borosilicate.
FGQuartz supplies complete quartz labware sets for trace element laboratories: crucibles and evaporation dishes for sample preparation, beakers and flasks for acid dissolution, ICP torch assemblies for instrument supply, and storage vessels for acid standards and reagents. All items are pre-cleaned in dilute HNO₃ before shipment to reduce surface adsorbed metals to a minimum.
Key equipment for trace element labs
- Quartz crucibles
- Evaporation dishes
- ICP torch assemblies
- Acid beakers
- Sub-boiling stills
- Digestion tubes
Ashing · Fusion · Calcination · Sintering
High-Temperature Sample Preparation
Ashing, fusion, calcination, and sintering are fundamental sample preparation steps across geochemistry, materials testing, food analysis, and industrial quality control. These techniques all require vessels capable of surviving extended exposure to temperatures that ordinary glassware cannot approach. A gravimetric determination requires that the crucible be ignited repeatedly to constant weight in a muffle furnace at 900–1000°C; a lithium borate fusion for XRF sample preparation requires melting at temperatures above 1000°C in a vessel that must not crack on rapid cooling over the platinum fusion dish.
Quartz crucibles are the standard vessel for ashing procedures up to approximately 1100°C. Unlike platinum crucibles — the only alternative at similar temperatures — quartz crucibles are affordable enough to use consumably in high-throughput laboratories and can be dedicated to specific sample matrices to prevent cross-contamination. Quartz boats and dishes handle the same temperature range in horizontal tube furnace configurations.
The thermal shock resistance of quartz glass is particularly valuable in fusion workflows where the crucible is transferred from a high-temperature muffle furnace to a cool bench surface in rapid succession. Borosilicate glass, and even some technical ceramics, would fracture under these conditions; fused silica absorbs the thermal gradient without cracking due to its near-zero coefficient of thermal expansion.
Key equipment for high-temperature labs
- Crucibles with lids
- Combustion boats
- Furnace tubes
- Tube furnace liners
- Evaporation dishes
- Reaction tubes
Photocatalysis · UV Synthesis · Solar Simulation · Actinometry
Photochemistry, UV Processing & Light-Driven Reactions
Photochemical reactions require vessel materials that transmit the wavelengths driving the reaction without absorbing them. Standard borosilicate glass is opaque below approximately 300 nm, which rules it out for reactions driven by near-UV or deep-UV radiation — including the majority of photocatalysis research, excimer lamp photodegradation studies, and actinometry using UV light sources. Quartz glass transmits efficiently from 150 nm through the visible and into the near-infrared, ensuring that the full output of UV lamps, mercury arc lamps, xenon lamps, and laser sources reaches the reaction mixture.
Photocatalysis is one of the fastest-growing areas of laboratory quartz use, driven by research into semiconductor photocatalysts (TiO₂, ZnO, g-C₃N₄) for water splitting, CO₂ reduction, and pollutant degradation. The photocatalytic reaction cell must transmit the UV component of simulated solar light or lamp output, be chemically inert to the reaction mixture, and allow gas sampling or product collection from the headspace. FGQuartz fabricates custom photoreactor vessels with defined illuminated volume, integrated inlet and outlet ports, and cooling jacket connections for temperature-controlled irradiation experiments.
Round-bottom flasks and immersion well reactors for photochemical synthesis benefit from quartz’s combination of UV transparency, thermal stability, and chemical resistance, allowing reactions to be run with UV sources of higher intensity and broader spectral range than would be possible in borosilicate glassware.
Key equipment for photochemistry labs
- Photoreactor vessels
- Immersion wells
- UV round-bottom flasks
- Lamp sleeves
- Gas sampling cells
- Actinometry cells
Wet Digestion · Sub-boiling Distillation · HClO₄ · Aqua Regia
Acid Digestion & Ultra-Pure Reagent Production
Wet acid digestion is the standard sample preparation method for elemental analysis of solid matrices — geological samples, food, environmental materials, biological tissues, and industrial products. The sample is dissolved in a mixture of mineral acids, often at elevated temperature, to convert the solid matrix into a clear solution suitable for introduction into ICP, AAS, or voltammetric instruments. The acid combination chosen depends on the matrix: aqua regia (HNO₃/HCl) dissolves most metals and many sulphides; HNO₃/HClO₄ destroys organic matter completely; HNO₃/HF digests silicates and refractory minerals.
Quartz beakers and flasks are used for open-vessel digestions with hot concentrated acids, particularly where perchloric acid fume generation makes a closed-vessel approach unsafe. Quartz is chemically resistant to all of these acid combinations at boiling temperatures — a condition that would severely attack and contaminate samples from borosilicate glassware through leaching of boron and alkali metals into the digest.
Sub-boiling quartz distillation stills are used by analytical laboratories to purify commercial reagent-grade acids to a quality level suitable for ultra-trace analysis. The sub-boiling technique — where the acid is evaporated below its boiling point using infrared heating and the vapour condensed in a quartz cold finger — produces acid with metal contamination orders of magnitude lower than even the best commercial ultra-pure acids. A quartz sub-boiling still for HNO₃ or HCl is a standard piece of equipment in geochemistry and environmental reference laboratories.
Key equipment for acid digestion labs
- Digestion beakers
- Sub-boiling stills
- Quartz condensers
- Distillation heads
- Evaporation dishes
- Reflux columns
Crystal Growth · CVD · Sol-Gel · Thin Film · Nanomaterials
Materials Science, Synthesis & Nanomaterials Research
Materials synthesis research pushes laboratory equipment to the edge of what materials can withstand — high temperatures, reactive gases, exotic chemicals, and processes that must be reproduced precisely across hundreds of experimental runs. Quartz glass provides the combination of thermal stability, chemical inertness, and dimensional reproducibility that this work demands, across a range of synthesis techniques from simple tube furnace calcination to complex CVD and sol-gel processing.
Crystal growth from the melt — including hydrothermal synthesis, Bridgman growth, and flux growth of oxide crystals — is often carried out in quartz ampoules sealed under vacuum or inert atmosphere. The ampoule serves as the reaction vessel during the growth run and must survive the thermal cycle without contaminating the crystal with impurity elements. Quartz ampoules are standard for chalcogenide crystal growth (ZnS, CdS, Bi₂Te₃), selenide growth, and halide crystal synthesis at temperatures within the quartz working range.
For CVD film growth experiments in academic research, a horizontal quartz tube furnace with a quartz reaction tube and quartz substrate holders is the standard apparatus. The entire gas flow path from the precursor inlet to the exhaust is quartz, ensuring that the film-forming chemistry is not contaminated by impurities from the vessel walls. FGQuartz supplies complete quartz tube furnace assemblies for CVD research, including the reaction tube, substrate boats, gas baffles, and end-cap assemblies with gas fittings.
Key equipment for materials labs
- Sealed ampoules
- CVD reaction tubes
- Substrate boats
- Crucibles
- Reaction vessels
- Gas baffles
Water Analysis · Soil Digestion · Air Monitoring · Food Safety
Environmental Testing & Food Safety Laboratories
Environmental and food testing laboratories operate under regulatory frameworks that specify method detection limits, blank requirements, and instrument performance criteria for legally binding analytical results. The choice of labware directly affects whether a laboratory can meet its regulatory detection limits — particularly for trace metals, which must be measured in the sub-microgram-per-litre range in drinking water and food samples where contamination from borosilicate glassware is unacceptable.
Soil and sediment analysis by acid digestion and ICP detection is a core workflow in environmental testing. The digestion step — typically aqua regia or microwave-assisted HNO₃/HF — must be performed in vessels that do not introduce the analyte elements being measured. For soil heavy metal panels (Pb, Cd, As, Cr, Ni, Zn, Cu, Hg), quartz digestion vessels provide blanks that are below method detection limits across the full suite of regulated elements.
Air monitoring for workplace chemical exposure and ambient pollution uses quartz impingers and sampling tubes to collect airborne contaminants. Quartz’s inertness ensures that the collected analyte is not lost to adsorption on vessel walls during the time between sample collection and laboratory analysis — a particular concern for polar organics and reactive inorganic species.
Key equipment for environmental and food labs
- Digestion vessels
- Evaporation dishes
- Impingers
- ICP torches
- Crucibles
- Sampling tubes
API Synthesis · Dissolution Testing · Sterilisation · Bioassay
Pharmaceutical Development & Biotechnology
Pharmaceutical development laboratories and bioanalytical facilities require glassware that can withstand steam sterilisation in autoclaves, chemical sterilisation with aggressive disinfectants, and the thermal demands of process development reactions at temperatures beyond the reach of standard lab glass. Quartz glass survives autoclave sterilisation cycles without surface degradation, leaching, or dimensional change — and unlike borosilicate glass, it does not introduce extractable boron or sodium ions that could interfere with sensitive biological assays.
Active pharmaceutical ingredient synthesis sometimes requires reaction conditions — high temperatures, strongly oxidising media, UV irradiation — that create problems for borosilicate reaction vessels. UV-assisted synthesis routes, which use photochemical activation to drive stereoselective reactions or photocatalytic transformations, require UV-transparent vessels that can also handle the organic solvent and acid environments typical of synthetic chemistry. Quartz round-bottom flasks and photoreactor vessels serve this role.
Dissolution testing for solid dosage forms (tablets, capsules) uses quartz vessel inserts in UV-Vis spectrophotometers where the dissolution medium must be directly observed at UV wavelengths to quantify drug release. The analytical wavelengths for many active pharmaceutical ingredients fall in the near-UV range where borosilicate glass absorption would reduce measurement sensitivity. Quartz flow-through dissolution cells and immersion probes are used in automated dissolution testing systems to achieve the necessary UV transparency.
Key equipment for pharmaceutical labs
- Reaction flasks
- Photoreactor vessels
- Dissolution cells
- UV flow cells
- Sterilisable vessels
- Synthesis tubes
Technical Knowledge
Getting the Most from Quartz Glass in the Laboratory
Understanding the capabilities and limitations of quartz glass equipment helps laboratories make the right procurement decisions and maintain performance over the full service life of each item.
Why Quartz Glass Resists Thermal Shock
The defining thermal property of fused silica is its near-zero coefficient of thermal expansion — its dimensions change almost imperceptibly with temperature. When a material expands or contracts by different amounts at different points across its cross-section — because the inside is hotter than the outside, or one face is in contact with a heat source — the differential strain creates internal stresses. If those stresses exceed the tensile strength of the material, it fractures. Because fused silica barely changes size regardless of temperature, the stresses generated by rapid heating or cooling are negligible, and the material survives temperature transitions that would catastrophically fail borosilicate glass. This is why a hot quartz crucible can be placed directly on a cool bench surface, and why quartz furnace tubes can be cooled rapidly under flowing gas without cracking.
Devitrification: What It Is and How to Avoid It
Devitrification is the transformation of amorphous fused silica into crystalline cristobalite — a process that occurs when fused silica is held at temperatures in the range of 1050–1200°C for extended periods, particularly if the surface is contaminated with alkali metals, which act as nucleation catalysts for crystallisation. Devitrified quartz appears milky or opaque at the affected surface regions and is structurally weaker than the original amorphous glass. Devitrified furnace tubes generate particles and are more susceptible to fracture during thermal cycling. The main preventive measures are: keeping alkali and alkaline earth contamination off quartz surfaces (handle with clean gloves, avoid contact with sodium carbonate, potassium compounds, or calcium-containing samples), and avoiding prolonged operation at the upper temperature limit. Quartz equipment that shows surface milkiness or opacity should be replaced before catastrophic failure occurs.
Chemical Compatibility: What Quartz Glass Can and Cannot Resist
Fused silica offers exceptional chemical resistance to nearly all laboratory reagents. Concentrated and dilute forms of hydrochloric acid, nitric acid, sulphuric acid, phosphoric acid, perchloric acid, aqua regia, and hydrogen peroxide can all be used in quartz vessels at or near boiling temperatures without significant attack on the glass. Strong alkali solutions — particularly concentrated sodium hydroxide and potassium hydroxide — do attack fused silica at elevated temperatures by dissolving the SiO₂ network; alkaline digestions should be performed in platinum or PTFE rather than quartz. Hydrofluoric acid is the other critical exception: HF reacts rapidly with SiO₂ and will etch or dissolve quartz equipment entirely. Phosphoric acid at very high concentrations and temperatures above about 300°C can also cause slow surface attack. For all other common laboratory chemistry, quartz is the most chemically resistant glass available.
Cleaning and Maintaining Quartz Laboratory Glassware
For routine cleaning after organic or inorganic contamination, a hot dilute nitric acid soak (10–20% HNO₃) followed by thorough rinsing with high-purity deionised water is the standard protocol for trace element laboratories. This removes surface-adsorbed metals and leaves the quartz in the cleanest possible state for subsequent analytical use. For stubborn carbonaceous deposits from ashing, brief heating of the empty crucible to 900–1000°C in a muffle furnace will oxidise residual carbon. Avoid mechanical abrasion — quartz is hard but brittle, and scratching the surface creates stress concentration points that weaken the vessel for future thermal cycling. Never clean quartz with HF-containing solutions, strongly alkaline detergents, or hydrofluoric acid glass etching formulations. Ultrasonic cleaning in dilute acid is safe and effective for internal tube surfaces that are difficult to reach manually.
Maximum Operating Temperatures for Different Laboratory Equipment Types
Different quartz laboratory items operate at different temperature maxima depending on geometry and load. Crucibles used in muffle furnaces can operate continuously to around 1100°C and briefly to 1200°C for short calcination runs. Reaction tubes in horizontal tube furnaces are typically rated for continuous use to 1100°C; the actual useful life depends on the chemical environment inside the tube, the ramp rate, and whether devitrification-promoting contaminants are present. Quartz glassware used on hot plates — beakers, flasks, evaporation dishes — is typically operated well below the glass transition temperature; hot plate service rarely exceeds 400–500°C, well within the fused silica working range. Sub-boiling stills and condensers operate at modest temperatures well below 300°C. For any application approaching 1100°C, fused silica is preferred over lower-purity grades of quartz glass, which contain more impurities that accelerate devitrification at high temperature.
Selecting Between Clear and Opaque Quartz for Laboratory Use
Most laboratory quartz equipment is manufactured from clear fused silica, which allows visual observation of the sample and supports UV-Vis spectrophotometric monitoring of reactions or temperature measurement through the vessel wall by optical pyrometry. Opaque quartz — which contains a fine dispersion of microscopic voids that scatter and absorb light — finds laboratory use primarily in thermal management applications: as insulating liners inside tube furnaces, as spacer and baffle elements between hot and cool zones, and as thermal shielding for temperature-sensitive components. Opaque quartz has a much lower thermal emissivity than clear quartz, behaving as a thermal insulator rather than a blackbody radiator. In analytical work, the choice is almost always clear quartz; in furnace engineering, a combination of clear and opaque components optimises both the process zone transparency and the thermal efficiency of the system.
Material Comparison
Quartz Glass vs. Alternative Laboratory Vessel Materials
Understanding where quartz glass outperforms alternatives — and where alternatives may be appropriate — helps laboratories make rational vessel selection decisions for each application.
| PROPERTY / REQUIREMENT | QUARTZ GLASS (FUSED SILICA) | BOROSILICATE GLASS |
|---|---|---|
| Operating temperature >500 °C | ✓ Yes — to 1100 °C | ✗ No — limit ~500 °C |
| Thermal shock resistance | ✓ Excellent | ~ Moderate |
| UV transparency (<300 nm) | ✓ Excellent — to 150 nm | ✗ Opaque below ~300 nm |
| Resistance to mineral acids (hot conc.) | ✓ Excellent | ~ Good (leaches B, Na) |
| HF resistance | ✗ Not suitable | ✗ Not suitable |
| Resistance to hot alkali (NaOH, KOH) | ~ Limited — avoid above ~200 °C | ~ Limited |
| Ultra-low boron blank | ✓ Yes | ✗ No — boron glass |
| Ultra-low alkali metal blank (Na, K) | ✓ Yes | ✗ No — significant leaching |
| Cost vs performance for >800 °C use | ✓ Excellent value | ✗ Not applicable |
| Custom geometry fabrication | ✓ Yes — CNC + flame welding | ✓ Yes |
Manufacturing Capabilities
How FGQuartz Manufactures Laboratory Quartz Equipment
Flame Forming & Glassblowing
The traditional method for forming quartz laboratory glassware is oxy-hydrogen flame working — shaping and joining fused silica tubes, rods, and sheet using a high-temperature flame fuelled by hydrogen and oxygen. Skilled quartz glassblowers at FGQuartz produce crucibles, flasks, condensers, distillation heads, and complex custom vessels by flame forming, drawing, and welding. All flame-worked items are annealed after fabrication to relieve the internal stresses introduced during the heating and forming process. The quality of a flame-welded quartz vessel depends entirely on the skill of the glassblower and the quality of the annealing; at FGQuartz, all welded items are inspected under UV illumination to verify the absence of stress concentrations in the weld zones before shipment.
CNC Machining for Dimensional Precision
Laboratory equipment that requires tightly controlled external dimensions — crucibles that must fit precisely into analytical balances, combustion boats that must slide into specific furnace tube diameters, or reaction tubes with defined wall thickness uniformity — is produced by CNC turning and milling rather than or in addition to flame forming. CNC machining also enables production of features that flame working cannot achieve: flat-polished sealing faces, threaded connections, drilled ports, and ground joint male and female taper sections that mate with borosilicate joint equipment. This combination of CNC and flame capabilities allows FGQuartz to produce hybrid items that are impossible at a pure glassblowing shop or a pure machining facility.
Cleaning and Trace-Level Preparation
Laboratory quartz equipment for trace element analysis is supplied pre-cleaned to a standard suitable for analytical incoming use. The cleaning process at FGQuartz uses dilute HNO₃ followed by multiple ultrapure DI water rinses, drying under filtered air, and packaging in double-bagged cleanroom polyethylene. This pre-cleaning reduces the surface-adsorbed metal load on new equipment significantly below the level of uncleaned stock, reducing the number of conditioning acid soaks required at the customer laboratory before items can be placed into analytical service.