A labyrinth seal is a seal which creates a complicated path for liquids to pass through, making it challenging for liquids to cross the barrier created by the seal because they have difficulty making their way all the way through the labyrinth. These types of seals are used in a variety of settings, and can be used on objects which rotate and otherwise move. In fact, movement can make the labyrinth seal even more effective, depending on the design.
The labyrinth seal has a number of grooves which interlock with other grooves or teeth. This differs from most traditional seals, which use a single lip in an attempt to seal an opening. With the labyrinth seal, each groove acts as its own lip, distributing pressure across the seal rather than concentrating it in one area. While a labyrinth seal cannot deal with high pressure differentials, it can be used in many other types of environments.
Seals are used to keep substances such as grease and lubricant in, while keeping dirt, fluids, and other contaminants out. One advantage to this type of seal is that when small amounts of leakage occur across the seal, as is inevitable, contaminants from the outside still can't get all the way inside, and the materials being sealed may not make their way all the way to the other end. This minimizes fouling caused by mixing of contaminants and sealed fluids.
The labyrinth seal design also reduces friction, making it suitable for devices such as turbines. These seals can withstand conditions which might cause other seals to break down, and as long as they are well maintained, they should hold up very well. Materials such as plastic which are less likely to corrode than metals can even be used to create a labyrinth seal, giving the seal a longer life time. Specialty products for particular applications may be made with rare or precious metals and other unusual components which are believed to perform better.
Replacements for labyrinth seals which become worn or compromised can be obtained at hardware stores and through companies which stock replacement parts for various types of equipment. It's important to confirm that a replacement is designed to fit, as variations in design can create weak points in the seal which will make it less effective. Some labyrinth seals may be printed with a specific part number which can be used as a reference when picking up a replacement.
By Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a About Mechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.