API RP 6AF3 Second Edition PDF

The scope of this document is to provide design guidelines for API 6BX style flanges utilized as end and outlet connectors in high-pressure, high-temperature (HPHT) surface and subsea applications. For this document, HPHT applications are intended to mean flanges assigned a temperature rating greater than 350 °F or a pressure rating greater than 15,000 psi.

Service temperature ratings above 550 °F (288 °C) are outside the scope of this document.