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
DWK Life Sciences Wheaton™ Stoppers for Serum Bottles and Vials: Snap-on Stopper
Provide airtight covers
Fisherbrand™ Solid Rubber Stopper for Microchemical Apparatus
Trim to fit any opening from 4 to 12mm
Fisherbrand™ M35 Neoprene Stopper
Good for added chemical resistance and oil applications
Fisherbrand™ Solid Rubber Stoppers, No. 6.5
Solid rubber construction.
DWK Life Sciences Kimble™ Weighing Bottle Stopper Cap
Replacement cap for Kimble™ KIMAX™ 15146-series tall cylindrical weighing bottle
Corning™ PYREX™ Fritted Disc Stopper Assemblies for Gas Washing Bottles
Choice of coarse (C) or extra-coarse (EC) fritted disc
DWK Life Sciences Kimble™ Kontes™ Solid Pennyhead Glass Full Length Stoppers
Stoppers are used with laboratory glassware such as flasks and separatory funnels.
DWK Life Sciences Kimble™ Kontes™ Full-Length Standard Taper Pennyhead Stopper
Stoppers are used with laboratory glassware such as flasks, mixing cylinders and separatory funnels.
Corning™ PYREX™ Solid Glass Pennyhead Standard Taper Stoppers
For use with flask and separatory funnel
DWK Life Sciences DURAN™ GL 18 Silicone Seal Septa
Suitable for PBT screw cap with aperture. Heat resistance: 130°C (vapor) and 200°C (dry heat). Silicone is peroxide-cured
Cytiva Whatman™ Stopper for use with MV050 Vacuum Filtration Manifolds
Replacement Rubber Stopper for use with MV050 Vacuum Filtration Manifolds.
Corning™ PYREX™ Hollow Combination Standard Taper Joint and Reagent Bottle Stoppers
Choose from variety of sizes and taper types
DWK Life Sciences Wheaton™ Sleeve Style Stoppers for Vials without Crimp Closure
Provides injection site for multiple dose entry