Glass Stopper (Still Flask) 14/20

A Glass Stopper for a Still Flask 14/20 is a type of stopper used to seal a still flask (distillation flask) in laboratory glassware, designed with a 14/20 ground glass joint. Here's a detailed description of its features, function, and usage:

Key Features and Components:

1. Glass Material:

• The glass stopper is made from high-quality borosilicate glass, a material known for its resistance to thermal shock and chemical durability. This makes it suitable for a wide range of laboratory experiments involving volatile chemicals, solvents, and heat.
• The transparency of the glass allows for visual inspection of the contents of the still flask.

2. Function of the Stopper:

• The primary function of the glass stopper is to seal the still flask securely. In distillation processes, a tight seal is essential to prevent the escape of vapors and to maintain an airtight environment inside the flask.
• The stopper helps to contain the liquid in the flask while it is being heated during distillation. By sealing the opening, it also prevents contamination and leakage of any potentially hazardous or volatile substances.

3. 14/20 Ground Glass Joint:

• The 14/20 refers to the joint size: 14 mm is the outer diameter (OD) of the ground glass joint, and 20 mm is the length of the joint. This is a common size for smaller laboratory apparatus.
• Ground glass joints are designed to create a smooth, airtight seal. The surface of the glass stopper and the opening of the still flask are polished to fit together snugly. This ensures a tight, leak-proof connection, which is important for preventing the loss of vapors and maintaining the efficiency of the distillation process.
• The 14/20 joint size is compatible with other laboratory glassware that uses the same joint size, such as condensers, adapters, and other flasks.

4. Design and Shape:

• The stopper has a cylindrical shape with a slightly tapered end that fits into the neck of the still flask. The design ensures a secure fit and easy handling, especially when it needs to be removed or replaced during the distillation process.

5. Usage in Distillation:

• The glass stopper for a still flask is most used in distillation setups. A still flask is the primary vessel where the liquid to be distilled is heated. As the liquid evaporates, the vapors rise, and the stopper helps to maintain the integrity of the flask by preventing any loss of vapor or liquid.
• The stopper is important for controlling the pressure within the flask, preventing spills, and ensuring that no vapors escape into the lab environment.
• During distillation, the stopper may be removed temporarily if the flask needs to be refilled or if the distillation process requires access to the flask's contents.

6. Compatibility and Size:

• The 14/20 joint is a standard size used in many laboratory distillation and reaction setups, especially in smaller-scale experiments. The glass stopper is designed to fit 14/20 female ground glass joints, which are found on still flasks, allowing for a secure and uniform fit.

7. Applications:

• Laboratory distillation: Used in simple and fractional distillation processes to seal the still flask.
• Chemical reactions: When used in chemical synthesis or reactions involving heat, the stopper keeps the flask sealed.
• Vacuum applications: The stopper may also be used when the distillation apparatus operates under reduced pressure or vacuum conditions, ensuring that vapors do not escape and the system operates efficiently.

Summary:

A Glass Stopper for a Still Flask 14/20 is a specialized component used in laboratory distillation setups. It features a 14/20 ground glass joint, ensuring a tight, leak-proof seal to prevent vapor loss during heating. The stopper is made of durable borosilicate glass and is designed to securely fit the neck of a still flask, helping maintain pressure, temperature control, and safety during distillation or chemical reactions. Its compact size makes it ideal for smaller-scale laboratory processes.