Special Threads for Gas Cylinders
1 Scope
This standard specifies the terms, symbols, basic profile and dimension of taper thread and cylindrical pipe thread for gas cylinder.
This standard is applicable to taper thread connecting the neck to valve of gas cylinder and cylindrical pipe thread connecting cap and neck ring of such cylinder (hereafter referred to as cylindrical thread).
The taper thread connecting the fusible plug to plug seat of gas cylinder with safety device may also be used by reference to this standard.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 192 General Purpose Metric Screw Threads - Basic Profile
GB/T 196 General Purpose Metric Screw Threads - Basic Dimensions
GB/T 197 General Purpose Metric Screw Threads - Tolerances
GB/T 3505 Geometrical product specifications (GPS) - Surface Texture: Profile Method - Terms Definitions and Surface Texture Parameters
GB/T 13005 Terminology of Gas Cylinders
3 Terms, Definitions and Symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions established in GB/T 13005 and the followings apply.
3.1.1
basic plane
plane vertical to thread axis, with reference diameter, which is referred to as basic plane
Note: it's the large end plane for internal thread while the plane with distance to small end equal to basic distance for external thread
3.1.2
basic diameter
basic major diameter of internal thread or external thread
3.1.3
taper thread pitch
distance of parallel cone busbars between two points corresponding to adjacent teeth on pitch diameter line
Foreword i
1 Scope
2 Normative References
3 Terms, Definitions and Symbols
4 Taper Thread
5 Cylindrical Thread
