PTFE spring-energized seals are a popular choice for engineers. The reasons are many, including their long service life, even wear, and their ability to perform in some of the harshest environments. They work well in extreme temperatures; can even perform well in situations where operating conditions can vary significantly. They usually offer a low compression set, have a long shelf life, and work very well in non-lubricated applications. The use of PTFE results in extremely low friction and excellent chemical compatibility and users can choose from a variety of spring energizers.
As one of the key components of a spring-energized PTFE seals, each of these energizers offers a different set of characteristics that allow engineers to find just the type of seal to suit their application’s needs. In this article, we ae going to look at five different categories of energizers, and in what conditions they provide the best service: coil springs, V springs, helical flat springs, cantilevered finger springs, and elastomeric O-rings.
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When people picture the spring energizing seal, the first image that comes to mind may well be the wire coil spring, also known as a spiral pitch spring. One of its outstanding characteristics is low friction. The angled coil spring works well where low friction and high pressure are involved, and works best in medium speed applications
The V spring is a general purpose energizing spring, which offers good performance at a relatively low cost. The V ribbon spring (V ribbon spring energized seal) is the one to look at for the harshest, most severe applications your industry has to face. It has been accepted as an excellent candidate for cryogenic and vacuum applications.
The helical flat spring is another commonly used alternative. This energizer is well adapted to a wide range of pressures, from high all the way down to vacuum conditions. It has been found especially suitable for sealing in lightweight gases or liquids. As far as speed goes, it seems to perform the best under medium speed conditions.
One outstanding performer is the cantilevered finger spring, also known as a finger spring (probably because it the shape of it reminds you of the end of your finger). Seals energized by this spring have extremely low friction, and offer low to high pressure sealing. They are best adapted to applications with speeds ranging from low to medium.
An elastomeric O-ring energizer also has its uses, especially when the use of metal must be avoided. It’s adapted well to extreme pressures, much like the helical flat spring. It also works well when dead volume needs to be minimized.
PTFE Spring Engergized Seals A-Z
You can find PTFE spring-energized seals in everything from chemical injection pumps, to cryogenic coolers, to rocket engines, to high performance racing. They can be found in fuel and oxidizer lines, liquid chromatography systems, and brake systems. The next time you have a demanding application that requires an above-average seal, don’t forget to take a look at PTFE spring-energized seals.
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