GB/T 12716-2002 in English

《GB/T 12716-200260°密封管螺纹》由TC108（全国螺纹标准化技术委员会）归口，主管部门为国家标准化管理委员会。
本标准规定了牙型角为60℃、螺纹副本身具有密封性管螺纹（NPT和NPSC）的牙型、基本尺寸、公差和标记。内螺纹有圆锥内螺纹和圆柱内螺纹两种，外螺纹仅有圆锥外螺纹一种。内、外螺纹可组成两种密封配合形式：圆锥内螺纹与圆锥外螺纹组成“锥/锥”配合，圆柱内螺纹与圆锥外螺纹组成“柱/锥”配合。本标准适用于管子、阀门、管接头、旋塞及其他管路附件的密封螺纹联接。为确保螺纹联接密封的可靠性，应在螺纹副内添加合适的密封介质，例如在螺纹表面上缠胶带、涂密封胶等。

Scope

This standard specifies the tooth profile, basic dimensions, tolerances and markings of pipe threads (NPT and NPSC) with a thread angle of 60° and the thread pair itself has sealing properties. There are two kinds of internal threads, conical internal thread and cylindrical internal thread, and only one type of external thread, conical external thread. Internal and external threads can form two types of sealing fit: conical internal thread and conical external thread form a "cone/cone" fit, and cylindrical internal thread and conical external thread form a "column/cone" fit. This standard is applicable to the sealing thread connection of pipes, valves, pipe joints, cocks and other pipeline accessories. In order to ensure the reliability of the thread connection seal, a suitable sealing medium should be added to the thread pair, such as wrapping tape on the thread surface, applying sealant, etc.