Envelope that defines the short-term stress levels to avoid incremental damage to the pipe composite laminate.
- Note: 1 to entry: The threshold envelope is set equal to the long-term envelope at 65 °C (for GRE) or 21 °C (for GRUP and GRVE). As the threshold envelopes are set at fixed temperatures, there is no temperature subscript for the threshold envelope. These definitions of threshold envelope are to the best of present knowledge. However, the manufacturer remains responsible and can declare a more conservative threshold envelope.
Source: ISO 14692-1:2017, Petroleum and natural gas industries — Glass-reinforced plastics (GRP) piping — Part 1: Vocabulary, symbols, applications and materials, Second Edition, August 2017. Global Standards