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 11 48 mm BDia Black 0 PK7
The Grainger 16VC09 is a 16-ounce aerosol can of CRC Brakleen non-chlorinated brake parts cleaner. It is a fast drying, non-flammable spray that removes oil, grease, brake fluid, and other contaminants from brake linings and drums. It leaves no residue and can be used on metallic and non-metallic brake parts. The aerosol spray reaches hard to access areas.
Grainger Stopper Sz 0 9 mm BDia Black 0 PK181
The EPDM Rubber Stopper from Grainger is a rubber stopper made from EPDM rubber. It has a diameter of 1-1/2" and a length of 1-1/2". The stopper has a solid top and no hole. It is rated for temperatures up to 250°F. The stopper provides an economical plug for closing off pipes and fittings. It creates an airtight and watertight seal. The EPDM rubber offers resistance to weather, ozone, aging, and chemicals. This stopper can be used in a variety of industrial applications.
Grainger Stopper Sz 16 90 mm BDia Black 0
The Grainger Approved 16-004 Stopper is a black rubber stopper with a 16 mm diameter and 90 mm length. It has a solid top and hollow bottom to fit various sized containers and test tubes. The stopper is made from high quality SBR rubber that resists cracking and provides an airtight seal. It can withstand temperatures from -20°F to 250°F. The stopper meets ASTM D3574 standards for rubber stoppers. It comes individually packaged. This basic rubber stopper is suitable for home, school, industrial, and laboratory use.