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
Ace Glass, Inc. #11 Ace-Thred solid PTFE plug, 7855-708 FETFE O-ring front seal
#11 Ace-Thred solid PTFE plug with front seal o-ring, for sealing column ends. Permits preparation and storage of columns. Supplied with size -012 FETFE o-ring.
Chemglass Life Sciences Septum Stopper, Sleeve Type, For 19/22-19/38 Outer Joints, White
Septum Stopper, Sleeve Type, For 19/22-19/38 Outer Joints, White. Sleeve type stoppers with a hollow plugs and sleeve extensions that folds down over the neck of a vessel, tubing, etc. The diaphragm can be punctured with a syringe needle, re-sealing after the needle is withdrawn.
Cole-Parmer Solid Black Rubber Stoppers, Standard Size 13.5; 3/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.
Chemglass Life Sciences Septum Stopper, Sleeve Type, for 8mm OD Standard Wall or 9mm OD Medium Wall, Red
Septum Stopper, Sleeve Type, for 8mm OD Standard Wall or 9mm OD Medium Wall, Red. Sleeve type stoppers with a hollow plugs and sleeve extensions that folds down over the neck of a vessel, tubing, etc. The diaphragm can be punctured with a syringe needle, re-sealing after the needle is withdrawn.
Chemglass Life Sciences Stopper #32, Pennyhead, Flask Length, Solid
#13 Low Actinic Red Stained Glass Stopper. Flask length solid penny head stopper with low actinic red stain.
WEST PHARMACEUTICAL SERVICES INC 20MM LYO RP1346 4023/50G 500PC
NC2044182 20MM LYO RP1346 4023/50G 500PC
Chemglass Life Sciences Stopper #22, Pennyhead, Flask Length, Solid
Stopper #22, Pennyhead, Flask Length, Solid. All sizes are solid with the exception of the #38 (CG-3018-08) which is hollow.
Chemglass Life Sciences 14/20 Stopper, Solid
14/20 Stopper, Solid. PTFE stopper has a Polypropylene extraction nut permitting easy removal of the stopper from the glass outer joint. The 14/20 and 19/22 are solid, while the larger sizes are hollow.