scope:

This specification defines the requirements for toroidal sealing rings ('O' rings) manufactured from materials which have been approved to D.T.D. 5594 - "Vulcanized Butadiene-Acrylonitrile Rubbers (Mineral Oil Resistant)". They may be used in reciprocating mechanisms or for static purposes particularly in contact with petroleum-based lubricants and hydraulic fluids (eg fluids complying with D.T.D. 585) within a temperature range of approximately -40°C up to 120°C for continuous operation.

Note. At ordinary temperature and in the absence of hostile environments, eg when properly stored, these rubbers deteriorate only very slowly. However, the rate of deterioration increases markedly with increased temperature and the service life of the rubber therefore depends upon the operational temperature. Conversely, the maximum temperature at which the rubber may be used depends upon the useful life required.