Funnels -Long Stem, Plastic

Quick Answer: A long stem plastic funnel is a moulded plastic funnel with an extended outlet tube that reaches down into narrow-necked flasks, bottles and burettes. It is used for transferring liquids and solutions without spills and for gravity filtration where the filtrate must go straight into a narrow vessel.

Reaching Past the Neck

When liquid is poured into a volumetric flask or a reagent bottle through a short funnel, it can run down the outside of the neck or splash off the shoulder. A long outlet delivers it well inside the vessel, below the neck, so every drop reaches the contents. That matters in quantitative work, where losing a few drops of a solution being made up to volume introduces an error, and in stores, where drips down a bottle leave residues on the label and the shelf.

Plastic makes the funnel light and hard to break, which helps when it is used repeatedly for refilling bottles or by younger students. Polypropylene and polyethylene are the usual materials; both cope with dilute acids, alkalis and salt solutions in the cold, yet they soften with heat and some solvents make them swell. The listing does not state the plastic, stem length or cone diameter.

A stem pushed tightly into a closed vessel’s neck can seal it, and trapped air then stops the flow, so lift the funnel slightly while pouring. For filtration with folded paper, the plastic analytical funnel is designed specifically for that job, and glass users can compare the long stem 60 degree funnel.

Applications

• Filling volumetric flasks when making up standard solutions, rinsing the funnel into the flask afterwards
• Filling burettes safely below eye level, with the funnel removed before the reading is taken
• Decanting reagents from stock bottles into smaller dropping or reagent bottles
• Adding liquids to a flask through a narrow neck during a reaction set-up

Care & Handling

• Lift or wedge the funnel slightly while pouring so air can escape from the vessel.
• Take the funnel out of a burette before reading or titrating, since a drip from it changes the volume.
• Keep separate funnels for acids, alkalis and organic liquids, marked on the rim, to avoid cross-contamination.
• Wash with warm detergent solution and a narrow bottle brush for the stem, then rinse with distilled water.

Specifications

Why Choose LabEquip

Laboratories that make up many solutions and refill reagent bottles use a long stem plastic funnel every day, and schools value its resistance to breakage. LabEquip lists it with the chemistry lab equipment; send diameters and quantities via the contact page.

Frequently Asked Questions

Why use a long stem funnel instead of a short one?

The long outlet reaches inside a narrow neck, so liquid does not run down the outside of the vessel or splash off the shoulder. That prevents losses when making up solutions and keeps bottles clean.

Why does the liquid stop flowing into the bottle?

The stem is probably sealing the neck, so air inside cannot escape. Raise the funnel a little, or slip a folded strip of paper or a thin rod between stem and neck to leave an air path.

Can this funnel be used to fill a burette?

Yes. Set the burette at a height where the funnel is below eye level, pour slowly, and remove the funnel before reading the burette, because a drop falling from it would change the reading.

Is plastic suitable for all liquids?

It suits most aqueous solutions of acids, alkalis and salts. Hot liquids and some organic solvents can soften or swell plastics, so use a glass funnel for those, or check the plastic’s compatibility first.

Can it be used with filter paper?

It can, but a funnel designed for filtration, with a standard cone angle and ribs, filters faster and holds the paper better. Use the long stem funnel mainly for transfer and occasional filtration.

How do I clean the narrow stem?

Run warm detergent solution through it and scrub with a long, narrow bottle brush, then rinse several times with tap water and finally with distilled water. Stand it upside down to drain and dry.

Last Updated: September 2026