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
Chemglass Life Sciences #9 PTFE Stopper, Black Handle
#9 PTFE Stopper, Black Handle. Flask length PTFE stopper with color coded handle.
Chemglass Life Sciences 19/22 Stopper, Solid
19/22 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.
Ace Glass, Inc. #18 Ace-Thred solid PTFE plug, 7855-721 FETFE O-ring front seal
#18 Ace-Thred solid PTFE plug with front seal O-ring, for sealing column ends. Permits preparation and storage of columns. Supplied with size -113 FETFE O-ring.
Cole-Parmer Solid Color-Coded Silicone Stoppers, Standard Size 9.5, Pink; 5/Bag
Silicone bubbles make these stoppers lightweight—they 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 bg/cs.*
Ace Glass, Inc. Septa, white rubber, sized for 14/20 joints, sp/12
Septa, white rubber, sized for 14/20 joints, sp/12
Ace Glass, Inc. Septa, red rubber, sized for 24/40 joints, sp/12
Septa, red rubber, sized for 24/40 joints, sp/12
Ace Glass, Inc. #7 solid nylon plug, 7855-712 FETFE O-ring back seal
#7 solid nylon plug, 7855-712 FETFE O-ring back seal
Ace Glass, Inc. #36 Ace-Thred solid nylon plug, 7855-772 FETFE O-ring front seal
#36 Ace-Thred solid nylon plug with front seal O-ring, for sealing column ends. Permits preparation and storage of columns. Supplied with size -125 FETFE O-ring.
Ace Glass, Inc. Trap, stopper, vacuum, bent vertical tube, 29/42, 13mm inner& side tube OD
Trap, stopper, vacuum, bent vertical tube, 29/42, 13mm inner& side tube OD