1. Scope
This standard specifies the type, dimension, technical requirements and marking of PTFE envelope gaskets for use with steel pipe flanges (Class designated).
This standard is applicable to the PTFE envelope gaskets for use with raised-face steel pipe flanges that the nominal pressures are Class150 (PN20) and Class300 (PN50) and the working temperature is less than or equal to 150℃ (specified in HG/T 20615).
Note: As for the use of the gaskets in which contain the material of asbestos, it shall meet the requirements of the relevant laws and regulations. If the aforesaid gaskets are used, the protective measures shall be adopted to prevent man from damaging.
2. Normative references
The following provisions contained in the following standards are turned into the provisions of this national standard by being referred in this national standard. For date reference, the subsequent amendments to (excluding amending error in the text) or revisions of, any of these publications do not apply. 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. For undated references, its latest edition referred to applies.
GB/T 3985 "Compressed asbestos fiber jointing"
GB/T 13404 "PTFE envelope gaskets for use with pipe flange"
HG/T 20615 "Steel Pipe Flange (Class Designated)"
HG/T 20635 "Specification for Selection of Steel Pipe Flange, Gaskets and Bolting (Class designated)"
QB/T 3625 "PTFE Sheet"
QB/T 3626 "PTFE Steel Bar"
Contents
1. Scope
2. Normative references
3. Gasket type and dimension
4. Technical requirements
5. Marking and Packaging
