1. Standards of: American Society of Mechanical Engineers (ASME), Deutsches Institut für Normung (DIN), Code de Construction des Appareils à Pression (Construction Code for Pressure Vessels, CODAP), and French Nuclear Piping Code (RCCM).
2. Research carried out by the Pressure Vessel Research Council (PVRC), the Tightness Testing & Research Laboratory (TTRL), the Materialprüfanstalt in Stuttgart (Materials Testing Institute, MPA), BHR Group Ltd in the UK, and the Centre Technique des Industries Mécaniques (Technical Centre of Mechanical Engineering, CETIM) in France. [The new gasket material standards were described in Sealing Technology in August 2003.]
3. Helicoflex leakage of 1 × 10−11 standard cubic centimetres per second of helium.