1 Scope
This standard specifies the requirements for thread form, dimensions, tolerances and designation for parallel internal and taper external threads with 55° thread form angle for pairs on which pressure-tight joints are made.
This standard is applicable to the threaded jointing for pipes, valves, fittings, plugs and other pipeline equipment.
An appropriate jointing medium is allowed to be used on the thread pair, e.g. threaded surface wrapped in tape and coated with sealant.
2 Normative References
The following standards contain provisions which, through reference in this test, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.
GB/T 14791-1993 The Terms of Screw Threads (neq ISO 5408:1983)
3 Definitions and Symbols
3.1 Definitions
All the thread terms used in this standard, other than the following two terms, comply with GB/T 14791.
Foreword i
ISO Foreword ii
1 Scope
2 Normative References
3 Definitions and Symbols
4 Thread Form Design
5 Basic Dimensions
6 Chamfers
7 Tolerances
8 Thread Lengths
9 Designation
