This document defines the requirements for the design, manufacturing, materials, welding, quality control, assembly, testing, documentation and process control of axial, ball, check, gate and plug valves for application in the oil and gas industries. This document applies to ASME Class 150, 300, 600, 900, 1 500, and 2 500. This document is a supplement to API 6D, 25th edition (2021), the requirements of which are applicable with the additions specified in this document.