GB/T 9126.1-2023
Non-metallic flat gaskets for pipe flangesPart 1:PN designated (English Version)
- Standard No.
- GB/T 9126.1-2023
- Language
- Chinese, English version preview
- Release Date
- 2023
- Published By
- General Administration of Quality Supervision, Inspection and Quarantine of the People¡®s Republic of China
- Latest
- GB/T 9126.1-2023
- Replace
- GB/T 9126-2008 ²¿·Ö´úÌ棺GB/T 9129-2003
- Scope
- This document specifies the type, material, requirements, test methods, inspection rules, marking and logo, packaging, storage and transportation of non-metallic flat gaskets for PN series pipe flanges. This document is applicable to non-metallic flat gaskets with a nominal size less than or equal to DN4000 and a nominal pressure of PN2.5~PN63.
- Introduction
GB/T 9126.1-2023 Standard Overview
This standard specifies the type, material, requirements, test methods, inspection rules, marking and marking, as well as packaging, storage and transportation of non-metallic flat gaskets for PN series pipe flanges.
Analysis of major changes
- Delete asbestos rubber sheet gasket material: The relevant content in GB/T 9126-2008 and GB/T 9129-2003 is no longer applicable.
- Add gasket type: Add bolt hole type (FF) and flat ring type gasket (FR) for flat flanges, and metal inner edging (FR-E) can be set.
- Add material requirements: Including technical indicators of high-performance materials such as modified polytetrafluoroethylene (RPTFE) and expanded tetrafluoroethylene (EPTFE).
- Optimized dimensional parameters: The dimensions of PN series gaskets in the range of DN 700-DN 4000 have been adjusted, and the applicability requirements of multiple specifications have been added.
- Strict limit deviation: The dimensional limit deviation requirements for gaskets for flat and tight face flanges, concave and convex face flanges, and tongue and groove face flanges have been clarified.
Material and performance comparison table
Material type Shore hardness (HA) Tensile strength (MPa) Applicable temperature range (¡ãC) Sealing performance index Rubber sheet 70 ¡À5 ¡Ý10 -40 to 80 ¡Ü5.0¡Á10-4 cm?/s Asbestos-free fiberboard 80 ¡À5 ¡Ý20 -60 to 150 ¡Ü3.0¡Á10-4 cm?/s Polytetrafluoroethylene (PTFE) sheet 65 ¡À5 ¡Ý12 -70 to 240 ¡Ü2.0¡Á10-3 cm?/s Modified polytetrafluoroethylene (RPTFE) sheet 75 ¡À5 ¡Ý15 -60 to 280 ¡Ü4.0¡Á10-4 cm?/s Technical indicators and application cases
Application scenario:EPDM gasket with bolt hole for DN 80 PN10 flat flange.
Marking example:Non-metallic flat gasket GB/T 9126.1 FF DN80-PN10 EPDM
Performance indicators:Compression rate 7-17%, rebound rate ¡Ý25%.
Standard formulation background and technological evolution
The GB/T 9126 series of standards was originally issued in 1988 and has undergone many revisions, reflecting the rapid development of pipe flange sealing technology. This revision focuses on the application of new materials and the advancement of manufacturing processes, and is compatible with the PN and Class series of the current pipe flange standards.
Implementation suggestions
- Material selection and matching:Choose appropriate gasket materials according to working conditions. For example, RPTFE or EPTFE is recommended for high temperature environments, and polytetrafluoroethylene can be used for corrosive media.
- Dimension verification:Measure and inspect the inner and outer diameters, thickness and center circle diameter of the bolt hole of the gasket strictly in accordance with Tables 1 to 4.
- Performance testing:Periodically sample and test key indicators such as compression rate, rebound rate and sealing performance to ensure compliance with the requirements of Tables 7 and 8.
- Storage management:Rubber and asbestos-free fiber gaskets should be stored in a dry and cool place, away from direct sunlight, and the validity period shall not exceed 18 months.
GB/T 9126.1-2023 Referenced Document
- GB/T 12385-2008 Test method for sealing performance of gaskets for pipe flanges
- GB/T 12621-2008 Standard test method for stress relaxation of gaskets for pipe flanges
- GB/T 12622-2008 Standard test method for compressibility and recovery of gaskets for pipe flanges
- GB/T 5574 Industrial rubber sheet
- JC/T 2052 Compressed non-asbestos fibre gasket materials
- QB/T 5257 Polytetrafluoroethylene (PTFE) sheet
GB/T 9126.1-2023 history
- 2023 GB/T 9126.1-2023 Non-metallic flat gaskets for pipe flangesPart 1:PN designated
- 2017 GB/T 17727-2017 Nonmetal material gaskets for marine flange
- 2008 GB/T 9126-2008 Dimensions of non-metallic flat gaskets for pipe flanges
- 2003 GB/T 9126-2003 Dimensions of Non-metallic flat gaskets for pipe flanges
- 1989 GB/T 2502-1989 Marine pipe flanges-soft gasket
GB/T 9126.1-2023 Non-metallic flat gaskets for pipe flangesPart 1:PN designated has been changed from GB/T 9126-2008 Dimensions of non-metallic flat gaskets for pipe flanges.