Stoppers
Stoppers, also known as bungs, are used to give an airtight seal to laboratory flasks and test tubes by fitting tightly inside the neck of the container and preventing material from spilling. Stoppers can be made of glass, cork, rubber, or silicone. They are typically designed with a conical shape, but straight, flanged, and tapered options are also available.
Stoppers are the preferred choice for many applications requiring a tighter seal or a greater degree of chemical resistance. They also provide a good seal when a solution needs to be shaken or mixed without spilling. Stoppers are generally cylindrical in shape and have a tapered bottom end. They may be marked with a stopper number or size on the top and bottom diameters of the stopper. Sizing can vary among manufacturers.
Stoppers are available in a solid design or with holes known as positions placed in the top. Positions allow easy access to the material contained in the sealed vessel by pipettes, tubing, or other equipment without full removal of the stopper.
What Types of Stoppers Are Available?
• Turnover stoppers have external serrations to create an excellent internal seal combined with a flexible turnover sleeve that folds down over the container’s neck to create a double seal
• Serum bottle or vial stoppers have two or three legs with external serrations or straight sides and a flanged top to create an airtight seal
• Straight bromobutyl plug-type stoppers provide a maximum seal for vials and serum bottles with a straight-wall glass finish
• Ultra-pure, straight bromobutyl plug-type stoppers provide high chemical purity and low gas permeability. They offer excellent performance during freeze drying processes such as lyophilization, where stoppers must remain stable during transfer and sublimination phases
• Silicone recessed septa stoppers are non-toxic and have external serrations to create an effective internal seal
Grainger Stopper Sz 0 13 mm BDia Black 0 PK75
The Grainger 16TW25 is a 16-inch diameter, two-blade, aluminum propeller for small aircraft. It has a pitch of 25 inches and is designed for engines up to 65 horsepower. The propeller is constructed from heat treated aluminum alloy for strength and durability. It uses a standard aircraft prop bolt hole pattern and includes all necessary hardware for installation. The propeller provides smooth and efficient performance for light aircraft.
Accuflow Systems Saint-Gobain Versilic Stopper, Silicone, 8D, 20 mm
Peroxide-cured silicone stoppers designed for laboratory use. These chemically and biologically neutral closures are non-toxic, odorless, non-adherent, and resistant to aging. They withstand a wide temperature range and meet common laboratory standards, making them suitable for tissue culture and general laboratory containment.
- Material: Peroxide-cured silicone.
- Dimensions: Bottom 4 mm, Top 8 mm, Height 20 mm.
- Temperature range: -70°C to 250°C (-94°F to 482°F).
- Compliance: DIN 18271, FDA/BGA approvals.
- Pack quantity: 500 per pack.
- Properties: Chemically and biologically neutral, non-toxic, odorless, non-adherent, resistant to aging.
- Applications: Tissue culture, microbiology, hematology, food science, laboratory containers.
