Understanding What Seals Are and How They Work

By Dichtomatik on 20 April 18 Article,Industrial Distributors,News

rotaryseals_mainWhat do you do when you have a shaft that needs to pass through or into liquid or gaseous environments, while spinning at high RPMs, but without allowing any of the outside environment to get through?  That’s when you need a seal.

Seals are often complicated, but necessary for many applications.  This is exactly the sort of solution which we at Dichtomatik Americas specialize in.   There are several different ways to approach the creation of seals, each with their own applications.


Understanding Your Options in Seals

Broadly speaking, there are three different types of seals – stuffing boxes, face seals, and lip seals.

  1. Stuffing Boxes

Stuffing boxes are the simplest and oldest of these sealing solutions, although still in use due to their simplicity—this is not a sealing solution in which Dichtomatik supports.  However, they are probably best suited for maritime operations and other relatively non-intensive applications.  They are “designed to fail” in the sense that the lubricating\sealing agent will melt and need to be replaced periodically.  Being easy to service makes it simple for them to be maintained, but not under industrial-scale usage.

  1. Face Seals

Face seals are one of the more generally all-purpose solutions and work by having a fixed bearing that’s compressed against a collar encircling the shaft. The main advantage of these seals is that they can accommodate vibration and some level of misalignment.

However, they generally require a source of pressure -such as air compression- to achieve the seal between the fixed bearing and the shaft.  Also, they require some source of lubrication.  This may be the outside water\liquid itself, seeping in and being trapped by the bearing, or it may be externally supplied lubrication.

  1. Lip Seals

Lip seals are the most common form of shaft seal in industrial application. These involve a spring which compresses a rubber ring around the shaft as it rotates.  Lip seals are drip-free, and in fact, must be replaced if any sort of leak occurs.

Like face seals, they also require constant lubrication – and it must come from an outside source.  Lip seals are also somewhat less resistant to vibration and misalignment, so they are better deployed in situations where the machinery runs to tight tolerances.

Get the Shaft Seals You Need from Dichtomatik Americas

Dichtomatik has the world’s largest supply of off-the-shelf sealing solutions of lip and face seals, as well as a team of engineers on-staff for creating custom solutions.  If you need seals, contact us for a quote.