![]() ![]() Unfortunately, making a PEEK back-up to the standard “MS” PTFE dash number dimensions is in most cases a bad idea.Ī standard PTFE size back-up made out of PEEK won’t work at all in a standard size static O-ring groove. ![]() Seal manufacturer Eclipse Engineering often gets requests for PEEK back-ups from customers experiencing failures with standard dash number PTFE back-up rings. The Potential Issues in Using a PEEK Back-Up Ring It can function at the same level as a metallic back-up ring, without the risk of metal-to-metal contact which could potentially gall the hardware. PEEK is an optimum performer in these situations. PEEK back-up rings can be used in multiple down-hole drilling applications where pressures can be up to 5,000 psi and temperatures often approach 350☏. Industries such as oil and gas require demanding working conditions. ![]() With a durometer around 85 Shore D and an upper temperature rating of close to 500☏, PEEK is an optimum material for high performance back-up rings. And if the application needs to operate in this temperature range, an alternative back-up ring material is needed.ĮP033 virgin PEEK by our friends at Eclipse has become a go-to for applications requiring a high-modulus and high-temperature plastic. Nylon and thermoplastic elastomer both have an upper temperature limit of around 250☏, and might see reduced mechanical properties at around 200☏.ĭiminished extrusion resistance means tighter extrusion gaps will be needed, something which isn’t always possible or desired. However, these materials present some limitations. Both materials will offer much better performance in terms of ultimate pressure handling when compared to virgin PTFE. Other than virgin PTFE, other common back-up materials that are more extrusion resistant are nylon and thermoplastic elastomers. If you’re experiencing sealing failures due to O-ring and back-up extrusion, it’s probably time to switch to a higher modulus back-up ring material. ![]() In higher pressure applications, or when an O-ring must contend with a larger-than-recommended extrusion gap, a virgin PTFE back-up ring might not be enough to prevent extrusion. Read on if switching from a PTFE to a PEEK back-up ring sounds like an enticing proposition to see what you need to consider before making the change. But with these advantages comes some potential issues. In certain applications, PEEK has some distinct advantages as a back-up ring material. But the most common custom material for back-up rings is usually PEEK (polyether ether ketone). Some applications require specific material properties and/or special material certifications.īack-up rings can be made for a variety of unique applications : Military-spec back-up rings out of fully certified AMS 3678/1 virgin PTFE Certified “MS” style back-up ring (MS27595 or MS28774) PTFE blends Thermoplastic elastomers Urethanes. While the design and functionality of a back-up ring rarely changes, the material selected can greatly complicate this simple device. Solid or split back-up rings out of virgin PTFE can usually be found on the shelf, and are largely considered commodity items. By blocking off the extrusion gap, the pressure-handling ability of an ordinary O-ring is greatly increased. While the design principle and construction are incredibly simple, they greatly extend the usefulness of the most common and prolific sealing device in the world: the O-ring.īack-up rings are aptly named as they do just that: they back-up an O-ring.īack-up rings are commonly nothing more than a ring of polymer meant to space the O-ring away from the extrusion gap in hardware. Back-up rings serve an important role in world of seals. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |