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
Cole-Parmer Indenti-Plug L800-B Plastic Foam Stopper, 14-20mm Openings, 1000/pk
Durable and reusable foam stoppers are an economical way to keep the contents of your containers secure. Open-cell foam has a uniform density, leaves no fibers like cotton, is breathable, nonabsorbent, chemcial resistant, heat tolerant, and retains shape after repeated use. Can also be used as a cleaner for pipettes, tubes, vials and precision tubing. Autoclavable.
Thomas Scientific Stopper, Schoniger, 300/500 mL
6513C60 stopper was traditionally offered by Thomas for 300/500 mL combustion flasks; glass tip extends 50 mm below ground joint 6513C65 stopper is used for 1,000 mL combustion flasks; glass tip extends 90 mm below ground joint All feature U-shaped platinum gauze with 3 mm opening for insertion of the sample wrapper. For replacement Platinum Carrier, see Thomas number 6514F55.
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.*
Cole-Parmer Solid Black Rubber Stoppers, Standard Size 16; 1/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.
Cole-Parmer Two-Hole Black Rubber Stoppers, Standard Size 6; 22/pk
These two-hole black stoppers made with solid natural rubber stay pliable over a long period of time. Provide good tightness and adhesion, withstand laboratory conditions without hardening, and are ideal for use with nonaggressive or low concentration solutions.
Cole-Parmer Solid Green Neoprene Stoppers, Standard Size 6.5; 15/Pk
Green neoprene stoppers withstand petroleum products, fats, oils, and organic chemicals. Stoppers exhibit good resiliency and shelf-life. Each stopper has its size in raised figures on top. Contain no sulfur.Autoclavable.
West Pharmaceutical Services Inc STOPPERS, 13MM, 4432/50 B2/FLU
Stoppers, 13mm, 4432/50 B2/Flurote West Pharmaceutical
Cole-Parmer Essentials Two-Hole Black Rubber Stoppers, Standard Size 1; 63/Pk
These two-hole black stoppers made with solid natural rubber stay pliable over a long period of time. Provide good tightness and adhesion, withstand laboratory conditions without hardening, and are ideal for use with nonaggressive or low concentration solutions. Each stopper has its size marked in raised figures. Low sulfur content. Withstand temperatures from 13 to 158F (25 to 70C).
WEST PHARMACEUTICAL SERVICES INC 20MM SERUM NOVA PURE RP 1000/C
NC1820961 20MM SERUM NOVA PURE RP 1000/C
Chemglass Life Sciences #27 PTFE Stopper, Red Handle, Hollow
#27 PTFE Stopper, Red Handle, Hollow. Flask length PTFE stopper with color coded handle.
Chemglass Life Sciences #19 PTFE Stopper, Green Handle
#19 PTFE Stopper, Green Handle. Flask length PTFE stopper with color coded handle.
Chemglass Life Sciences #38 PTFE Stopper, Black Handle, Hollow
#38 PTFE Stopper, Black Handle, Hollow. Flask length PTFE stopper with color coded handle.
Chemglass Life Sciences Septum Stopper, Sleeve Type, For 29/26-29/42 Outer Joints, Red
Septum Stopper, Sleeve Type, For 29/26-29/42 Outer Joints, 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.