api 5000API 5000, 10000 are used in reference to wellhead 'christmas tree' pressure ratings as well used for the wing valve, master valve ratings. There may be hher classes asAPI Flange Wehts and Dimensions. Search. Skip To Content [email protected] 1-800-256-1292 Request a Quote MTR Login. 1-800-256-1292 [email protected] Search RFQ. ... 5,000 PSI - Type 6B API 6A - Table E.3 . Nominal size of