This guideline also recommends individual packaging, but in our 40 years of being in business, bulk packaging shows no difference over time. Unless compliance regulated, shelf life of all rubber parts should be considered unlimited.ĪRP5316 can be a useful guideline for companies who don’t have a recommended shelf-life control on elastomeric seals.

Ozone – storage rooms shall not contain any equipment that is capable of generating ozone.Īs stated in the studies above, rubber seals have the capability to last long periods of time in storage.Light – protected from light sources especially direct sunlight or intense artificial light.Humidity – less than 75% (AU/EU less than 65%) if not stored in sealed moisture proof bags.*HNBR, Epichlorohydrin(ECO), Polyacrylate (ACM), Ethylene Acrylic (AEM) can be grouped similar to NBR due to similarities in polymer types. The standard includes shelf-life recommendations, need for traceability and proper storage of elastomeric seals. To alleviate some confusion, ARP5316 was created as a recommended practice to address elastomeric seals - as well as offer a control document for companies that require one. The study also led to more confusion, since companies still insisted on age control and were still referencing AS1933 or MIL-HDBK-695. This released aerospace elastomers from age control. However, the study left reference to AS1933: Age Controls for Hose Containing Age-Sensitive Elastomeric Materials. In 1994, EPRI NP-6608 concluded that with proper storage, the shelf life of elastomer seals could be 32 years.īased upon numerous studies, MIL-STD-1523 had been canceled in 1995 without replacement. The authors concluded that age control had been very conservative and could be extended with proper storage. This reviewed previous studies and age control document MIL-HDBK-695.

In 1989, Bruce Boyum and Jerral Rhoads led a new study called Elastomer Shelf Life: Aged Junk or Jewels. In 1984, a new “A” revision was released which extended shelf life from 12 quarters to 40 quarters. From this document, shelf lives of elastomers procured by government agencies were limited to 12 quarters from the cure date of the seal. The study concluded that the overall properties of elastomeric materials improved over a given time, which made age control less restrictive.In 1973, this resulted in MIL-STD-1523, which superseded ANA Bulletin 438. Many programs went on to study age control from these materials – summarized in Air Force report, AFML-TR-67-235. However, the standard can also be used as a guideline and recommended practice for the shelf life of rubber seals, gaskets and many industrial and commercial grade elastomers.Īfter World War II, ANA Bulletin 438 established an effort to impose age control on critical elastomer sealing devices.This resulted in confusion and costly increases to seal procurement. ARP5316 has become the industry standard for the shelf life of aerospace elastomeric seals. In 1998, the Society of Aerospace Engineers (SAE) issued Aerospace Recommended Practice (ARP)5316. Shelf Life: The storage period prior to installation of elastomeric seals and seal assemblies into hardware components. What are best practices for storing elastomeric seals? How do you properly calculate elastomer age? Unfortunately, the answer to these questions are not so simple. Apple Rubber receives a number of requests to determine the shelf life of a given rubber part.

Shelf life calculation