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 Stopper, Cap Style, #25 O-Ring Joint
Stopper, Cap Style,#25 O-Ring Joint. Replacement part for 4-Port Vacuum Manifold Right Handed Trap Assembly (item #50872175). #25 o-ring joint supplied complete with a cap style stopper that attaches to the cleanout at the end of the vacuum line.
Uline Silicone Rubber For Deluxe Impulse Sealer With Cutter - 16"
Silicone Rubber For Deluxe Impulse Sealer With Cutter-16IN
Ace Glass, Inc. Septa, red rubber, sized for 14/20 joints, pk/144
Septa, red rubber, sized for 14/20 joints, pk/144
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.
Chemglass Life Sciences Septum Stopper, Sleeve Type, For 29/26-29/42 Outer Joints, White
Septum Stopper, Sleeve Type, For 29/26-29/42 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.
Chemglass Life Sciences Stopper, Safe-Lab, Flask Length, PTFE, Size 16
Stopper, Safe-Lab, Flask Length, PTFE, Size 16. Flask length PTFE stopper has a Polypropylene extraction nut permitting easy removal of the stopper from the flask. All sizes are solid.
Chemglass Life Sciences Septum Stopper, Suba-Seal, For 29/26-29/42 Outer Joints and 25.5mm ID Tubing
Septum Stopper, Suba-Seal, For 29/26-29/42 Outer Joints and 25.5mm ID Tubing. Suba-Seal septa are a flanged stopper with a hollow plug and sleeve extension that folds down over the neck of the vessel. In addition to the pull over sleeve, Suba-Seal stoppers have a series of annular serrations on the plug portion of the septa. Each of these serrations depress along the inner wall of the glass vessel to form an extremely effective air-tight seal. Stoppers are made from natural red rubber and sold in the package quantities listed below.
Uline Silicone Rubber For Deluxe Impulse Sealer With Cutter - 24"
Silicone Rubber For Deluxe Impulse Sealer With Cutter-24IN