Wholesale 16mm Laboratory Digestion Tubes & PTFE Closures

Description

Feature

Specification

Product

FAQ

Packing and Delivery

Overview

In environmental monitoring and wastewater testing, Chemical Oxygen Demand (COD) analysis demands laboratory consumables capable of surviving extreme thermal stress and aggressive acidic reagents without leaching trace impurities. This premium series of 16mm laboratory digestion tubes and engineering-grade PTFE-lined screw closures is strictly manufactured to eliminate structural structural failures, cross-contamination, and volatile background interference during high-pressure digestion procedures.

The geometric specifications and physical tolerances of these tubes are calibrated precisely to ensure flawless mechanical fitment into standard thermal reactor blocks and spectrophotometer wells, avoiding any operational jamming. Featuring distinct HC (High Chemical Inertness) and LVB (Low Volatile Background) material classifications, this product workflow delivers the rigorous hermetic seal required by EPA and ISO methods during the standard two-hour acid heating cycle at 150°C.

Product Features

This premium series provides absolute physical integrity and zero trace-element background interference during rigorous high-temperature acid digestion processes.

Extreme Thermal Tolerance: Engineered using Class A borosilicate glass to continuously withstand standard 2-hour thermal digestion cycles ranging from 150°C to 165°C safely.

Targeted Material Grading: Available in both HC (High Chemical Inertness) and LVB (Low Volatile Background) configurations to perfectly align with specific analytical detection limits.

Hermetic Vapor Barrier: Outfitted with pure PTFE liners facing the inner tube chamber to completely block aggressive sulfuric acid and potassium dichromate vapors.

Calibrated Geometric Dimensions: Manufactured to a strict 16mm outer diameter tolerance, ensuring flawless fitment inside standard heating blocks and spectrophotometer wells.

Flexible Setup Configurations: Offered in both flat-bottom and round-bottom geometries across multiple length variations to easily streamline diverse sample preparation workflows.

Specification

Technical Specifications & Ordering Information

Part No.	Product Description	Bottom Type	Material Grade	Dimensions (D × L)	Pcs/Pack
COD-V50	10mL Clear Glass Test Tube for Water Analysis & COD Digestion, High Chemical Inertness (HC Type)	Round Bottom	Borosilicate Class A	16 × 100 mm	100
COD-VF50	10mL Clear Glass Test Tube for Water Analysis & COD Digestion, High Chemical Inertness (HC Type)	Flat Bottom	Borosilicate Class A	16 × 100 mm	100
COD-VF50-90	9mL Clear Glass Test Tube for Water Analysis, Low Volatile Background (LVB Type)	Flat Bottom	Premium USP Type 1	16 × 90 mm	100
COD-V50-125	12mL Clear Glass Test Tube for Water Analysis & COD Digestion, High Chemical Inertness (HC Type)	Round Bottom	Borosilicate Class A	16 × 125 mm	100
COD-V50-150	15mL Clear Glass Test Tube for Water Analysis & COD Digestion, High Chemical Inertness (HC Type)	Round Bottom	Borosilicate Class A	16 × 150 mm	100

FAQ

This technical guide answers the most critical compatibility, material selection, and sealing safety questions raised by laboratory procurement officers.

Are these 16mm digestion tubes fully compatible with standard commercial reactor blocks?

Yes, the 16mm outer diameter is tightly calibrated to ensure a seamless fit in heating blocks from major analytical brands like Hach and Hanna.

What is the main structural advantage of choosing the flat-bottom version (COD-VF50)?

Flat-bottom tubes stand independently on open workbenches without requiring an external rack, speeding up sample pipetting and preparation steps.

How do I choose between the HC Type and the LVB Type?

Select the HC Type for standard heavy-duty thermal digestion; choose the LVB Type for low-range analytical limits where trace background interference must be eliminated.

Can the PTFE septa on the screw caps withstand concentrated heating acid vapors?

Yes, the pure PTFE liner layer directly faces the sample to provide an impenetrable chemical barrier against hot sulfuric acid and dichromate vapors.

Are these consumables delivered clean and ready for immediate laboratory use?

They are packaged in a controlled, clean environment. However, for ultra-trace or low-range standard protocols, a pre-washing procedure following your local SOP is recommended.

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Packing and Delivery

Packing

Each vial is individually protected in shrink-wrapped trays, 100–200 pcs per inner box, then packed into corrugated export cartons.

Labeling

Each carton includes lot number and product information for traceability.

Delivery Time

Normally 7–15 working days after order confirmation.

Shipping Options

Air freight, sea freight, or express (DHL/UPS/FedEx) available upon request.

Storage Condition

Store in a clean, dry environment at room temperature.

Company Profile

Zhejiang Aijiren Technology Co., Ltd.

A dedicated original manufacturer of chromatography and laboratory consumables.

10,000+ m² modern facility with Class 100,000 cleanrooms
Automated production lines and rigorous in-house quality control
High-volume capacity, fast lead times, and reliable global supply
OEM/ODM customization with full batch traceability
Trusted by laboratories and analytical instrument brands worldwide

VR Showroom

OEM/ODM Custom Laboratory Consumables

Aijiren turns your customized requirements—size, material, color, logo, or packaging—into reliable, ready-to-use products.

OEM/ODM

Precise manufacturing based on your drawings and specifications, with one-stop development support

Confidentiality

Full protection of all commercial information, molds, and designs

Stable Supply

Automated production ensures consistent quality and fast lead time

Technical Support

Dedicated team ensures smooth communication and hassle-free delivery

FAQ From Customers (VR Display)

What certificates do you have?

Aijiren is certified to ISO 9001:2015 by SGS, ensuring controlled manufacturing processes and stable, fully traceable product quality.

With continuous investment in R&D and multiple independent patents, we deliver high-performance and reliable consumables to laboratories worldwide.

Some of the certificates of Aijiren are displayed

What’s the MOQ? Do you accept small orders?

Aijiren supports both standard and small batch orders. While MOQ varies by product type, we are happy to accommodate smaller quantities for trial, testing, or special projects. Please contact us for specific requirements. aijiren Quality control

Is the quality guaranteed?

All Aijiren products undergo random sampling and multiple in-house quality tests. Each batch is fully traceable, ensuring stable and reliable performance for your laboratory work.

What kind of after-sales support does Aijiren provide?

Aijiren provides practical after-sales support:

● Returns & replacements: Any product affecting use or sales can be returned or replaced.

● Technical support: Assistance with product use and troubleshooting.

● Order tracking & follow-up: We monitor shipments and follow up to ensure timely delivery.

● Dedicated contact: Aijiren provides a direct contact for after-sales inquiries.

This ensures your laboratory work runs smoothly with minimal disruption.

How long will it take for orders?

The delivery time depends on the order quantity and whether customization is required:

In-stock products: shipped within 3–7 days after payment
Standard bulk orders: shipped within 2–4 weeks
OEM/ODM customized products: shipped within 3–5 weeks (depending on mold, logo, color, packaging, etc.)
Aijiren has automated production lines and a 100,000-class cleanroom, ensuring stable lead times and reliable supply.