Shelf life


This term is usually associated with the elastomers (rubber part) used in mechanical seals.

Buna “N” rubber is the biggest problem because of its sensitivity to ozone attack. Seals with Buna N parts are normally packaged in Kraft wax paper and then put into a box. The waxed paper protects the elastomer from ozone.

Opening the box and removing the Kraft waxed paper starts the clock.

Most rubber manufacturers give Buna N a shelf life of about one year when exposed to ozone.

The rubber bellows seal, supplied as original equipment in many pumps, is usually supplied with a Buna N boot or bellows.


  • On February 17, 2018