本文件规定了石油和天然气行业使用的井口和采油树设备的性能、尺寸和功能互换性、设计、材料、测试、检查、焊接、标记、搬运、储存、装运和采购的要求和建议。 本文件不适用于现场使用或现场测试。 本文件不适用于井口和采油树设备的维修，但与制造相关的焊接维修除外。 本文件不适用于用于安装和维修的工具（例如运行工具、测试工具、清洗工具、耐磨衬套和润滑器）。 本文件补充了API Spec 6A第21版（2018），其要求适用于本文件规定的例外情况。

This document specifies requirements and gives recommendations for the performance, dimensional and functional interchangeability, design, materials, testing, inspection, welding, marking, handling, storing, shipment, and purchasing of wellhead and tree equipment for use in the petroleum and natural gas industries. This document does not apply to field use or field testing. This document does not apply to repair of wellhead and tree equipment except for weld repair in conjunction with manufacturing. This document does not apply to tools used for installation and service (e.g. running tools, test tools, wash tools, wear bushings, and lubricators). This document supplements API Spec 6A, 21st edition (2018), the requirements of which are applicable with the exceptions specified in this document.