scope:

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.

The current version of this guideline does not address thermal effects including gradient effects or subsea production equipment. Service temperature ratings above 550 °F (288° C) are outside the scope of this technical report. The flange designer should address thermal effects when designing flanges rated for high temperatures.