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
Hach Company Plastic BOD Bottle Stoppers
Unbreakable acrylic stopper for 300 mL BOD disposable bottles Qty 1
Ace Glass, Inc. 500mL gas wash stopper only, porosity A
500mL gas wash stopper with porosity A (145-174micron) fritted disc.
Ace Glass, Inc. 125mL gas wash stopper only, porosity C
125mL gas washing stopper with porosity C (25-50 micron) 25mm fritted disc diameter, and 40/35 joint. Inlet/outlet arms are 8mm O.D.
Ace Glass, Inc. Trap, stopper, vacuum, 40/50, 19mm inner & side tube OD
Trap, stopper, vacuum, 40/50, 19mm inner & side tube OD
Cole-Parmer Solid Color-Coded Silicone Stoppers, Standard Size 12, Yellow; 1/Bag
Silicone bubbles make these stoppers lightweightthey float on water. Withstand temperatures from 76 to 392>F (60 to 200>C). Stoppers are available in 14 color-coded sizes, given in both standard and Japanese size numbers. Softness and flexibility allow stoppers to fit a range of holes. Easily make openings for glassware fit your exact specifications with the optional cork borer set. 2 bags/case.
Cole-Parmer Solid Black Rubber Stoppers, Standard Size 2; 52/Pk
Black rubber stoppers stay pliant over a long period and withstand laboratory conditions without hardening. Stoppers retain resiliency even after repeated autoclaving. Each stopper has its size in raised figures on top. Contain some sulfur. Autoclavable.
West Pharmaceutical Services Inc 20mm Serum FluroTec™ Barrier Film-Laminated Ready-to-Sterilize Bromobutyl 4023/50 Stoppers with Envision™ Verification Process, Qty. 3,000 stoppers/bag
FluroTec™ barrier film-laminated serum stoppers are made from 4023/50 a bromobutyl elastomer and laminated with FluroTec™ barrier film to reduce the risk of a chemical interaction. These components are provided washed (ready-to-sterilize) and 100% vision inspected. This stopper configuration can be used with European blowback, North American blowback, or straight wall (no blowback) vials. West item number:10145417.
West Pharmaceutical Services Inc 20mm NovaPure® Ready-to-Sterilize Bromobutyl 4023/50 Serum Stoppers, Qty. 3,000 stoppers/bag
NovaPure® serum stoppers are made from 4023/50 a premium quality bromobutyl elastomer with West’s lowest particulate specification available. Laminated with FluroTec™ barrier film to help reduce particulate, limit drug interaction with the elastomer and reduce leachables. These components are provided washed (ready-to-sterilize) and 100% vision inspected. This stopper configuration can be used with European blowback, North American blowback, or straight wall (no blowback) vials. West item number: 70025047
Chemglass Life Sciences Stopper, Safe-Lab, Flask Length, PTFE, Size 27
Stopper, Safe-Lab, Flask Length, PTFE, Size 27. Flask length PTFE stopper has a Polypropylene extraction nut permitting easy removal of the stopper from the flask. All sizes are solid.