api 5000*Tolerances and ring gaskets are according to API 6A. Materials for API 6A Type 6B 5000 psi(34.5 MPa) Weld Neck RTJ Flange, API 6A 6B Weld Neck*Tolerances and ring gaskets are according to API 6A. Materials for API 6A Type 6B 5000 psi(34.5 MPa) Weld Neck RTJ Flange, API 6A 6B Weld Neck