api 5000API - ANSI Flange Conversation Chart - Free download as PDF File (.pdf), Text File (.txt) or read on for free. The document is a flange conversion chart that lists: - Nominal pipe sizeAPI Specification 6A covers wellhead and tree equipment as follows: API Specification 6A Wellhead Equipment Valves, Chokes, and Actuators Plugs, Connectors, and Gaskets Other