What Is The Difference Between API 6B And 6BX Flanges?

6B flange is not suitable for face-to-face connection. The connection tightening bolt force acts on the metal ring gasket. The size ranges from 2-1/16″ to 21-1/4″, and the pressure is 2000#, 3000# and 5000#.
6B flange is usually used in some working environments under medium and light conditions. It has reliable sealing performance and high load-bearing capacity. Therefore, it is often used in important equipment such as oil pipelines, compressors and refining equipment in the oil and gas industry.

6BX flange is designed with a convex face. It can be designed with a special weld neck that matches the standard pipe size. Depending on the tolerance, when the gasket is properly in place, the bolt force may act on the convex face of the flange. This support helps prevent damage to the flange or gasket due to excessive bolt torque. It is more reliable under high pressure, high temperature and extreme conditions, so it is suitable for use in harsh working environments. Its sealing performance is achieved by installing a metal sealing ring on the flange end, which can withstand extrusion deformation and thermal expansion under high pressure and high temperature to maintain sealing performance.