Dewar Flask


  • Double-Walled Design
  • Vacuum Insulation
  • Silvered Inner Surface
  • Low Heat Conduction
  • Cryogenic Storage
  • Size and Configuration
  • Thermal Insulation
  • Gas Management

Specifications and Details of Dewar Flask

A Dewar Flask is a specialized glass container used to maintain the temperature of liquids. It maintains the temperature of the stored liquid in the surrounding air by minimizing heat transfer. It uses a double-wall structure to create a strong vacuum to reduce convection and conduction heat transfer. The flask has silver-coated inner walls to block heat radiation and minimize contact points between the walls. This ensures that it has high thermal insulation.

It is often used for cryogenic storage, also known as cryogenic storage dewar. It is a dedicated vacuum flask that safely stores cryogenic materials with extremely low boiling points, such as liquid nitrogen or helium. This container is named after inventor James Dewar. It is widely utilized in low-temperature physics and chemistry applications. It comes in various sizes and forms, like open buckets, flasks with loosely fitted stoppers, and self-pressurizing tanks.

How this works?

The common thread among all dewars is its multi-layered wall design. It comes with a high vacuum in between and provides exceptional thermal insulation to slow the evaporation of cryogenic contents. Stringent safety measures are incorporated into the design of dewars to handle the gas released as cryogenic liquid boils away safely. It is essential for preserving ultra-cold substances for scientific, industrial, and laboratory applications. Its straightforward design and remarkable insulation properties make it invaluable in research and experimentation.

Temperature Range

  • Glass Dewar: -50 °C to -150 °C
  • Borosilicate Glass: 150 °C to -270 °C
  • Cryogenic Dewar Flask: -160 °C to -200 °C
  • Stainless Steel: -190 °C to 200 °C

Main Highlights

  • Double-Walled Design: A Dewar Flask features a double-walled structure with an inner and outer wall. These walls are separated to minimize heat transfer.
  • Vacuum Insulation: The space between the two walls is meticulously evacuated to create a high vacuum. This vacuum greatly reduces heat transfer through convection and conduction.
  • Silvered Inner Surface: The inner surfaces of the walls are coated with a layer of silver to block heat transfer by radiation.
  • Low Heat Conduction: The contact points between the two walls are kept to a minimum to reduce heat conduction further.
  • Cryogenic Storage: It is specifically designed for cryogenic storage. It can maintain extremely low temperatures, ideal for liquid nitrogen or helium.
  • Size and Configuration: It comes in various sizes and configurations, including open buckets, flasks with loose stoppers, and self-pressurizing tanks.
  • Thermal Insulation: The multiple layers in the walls, with a maintained high vacuum, provide excellent thermal insulation, reducing the rate at which the stored contents evaporate.
  • Gas Management: Precautions are taken in the design of the flask to safely manage the gas released as the cryogenic liquid slowly boils away.

Applications of Dewar Flask

Cryogenic Storage Dewar Flasks find a wide range of applications across various fields. It is mainly known for its role in cryogenic applications. It is specially used to store and dispense cryogenic gases such as liquid nitrogen, oxygen, helium, and hydrogen. It is essential for flash-freezing samples in research laboratories, making it an invaluable tool for scientific experiments. Vacuum Flask, a type of Dewar Vessel, has domestic uses. It maintains the temperature of beverages and food, keeping them hot or cold for extended durations.

It also plays a role in the oil and gas industry, insulating electronic components within wireline logging tools. It is also used in the medical industry during fertility treatments to store embryos safely. In scientific research, the flask is crucial for studying superconductivity. It even facilitates the safe transport of cryogenic liquids within factories or labs through portable Dewars equipped with casters and handles. It is a versatile tool for storing and transporting low-temperature liquid gases and high-temperature liquids, making them essential across many industries and scientific endeavors.

How to use dewar flask ?

  • Choose the appropriate Dewar Flask based on your needs, considering capacity, materials, and temperature requirements.
  • Fill it with the intended liquid or gas to be stored, ensuring it’s the cryogenic liquid for applications involving liquid nitrogen, oxygen, helium, or hydrogen.
  • Seal the Flask with the stopper or cap, venting the stopper in cryogenic applications to prevent pressure buildup.
  • Handle it carefully, especially when filled with cryogenic liquids, as it is delicate and prone to breakage.
  • Dispense cryogenic liquids slowly and safely using the Flask to ensure a two-handed grip for controlled liquid nitrogen release.

Safety Guidelines

  • Use a small flask or a transfer device for larger containers to handle liquid safely.
  • Prevent combustion risks by avoiding liquid air or oxygen in a Dewar Flask designed for nitrogen.
  • Ensure compliance with the manufacturer’s guidelines for cryogenic vessels.
  • Do not transport liquid nitrogen in passenger elevators.
  • Avoid causing breakage by not moving or bending the copper fill tube of a flask.
  • Those filling flasks should wear protective gear and maintain well-ventilated storage.
  • Keep it upright to prevent liquid discharge and frostbite.
  • Prevent frostbite by avoiding skin contact with liquid gas during use.
  • When handling it, always use the provided handles, not the neck.
  • Securely store cryogenic liquid vessels to prevent unauthorized access.
  • Prohibit smoking, flames, or sparks in areas with flammable cryogenic liquids.
  • Plan safe transport routes and use elevators without personnel inside to avoid oxygen displacement risks from potential spills.

Why us?

Techinstro is an experienced, well-equipped manufacturer and supplier of superior-quality Dewar Flask. Our Dewar Flask can be conveniently used for research and industrial purposes. We believe in staying ahead of time by employing technological innovations and the best quality raw materials in manufacturing the highest-grade products. We provide high-quality flasks at the most affordable prices. Our clients are our most valued asset, and we keep them satisfied by providing world-class customer service and after-sales service.

We can deliver anywhere globally, so call us now for a customized solution.