G 492 Technical Rule - Standard 06/2021 -PDF-file-
Gas Measuring Systems for an Operating Pressure up and including 100 bar
- Herausgeber/Verlag: DVGW
- Format: 30 pages
- Material: available as PDF only
- Ausgabe: 2nd edition 2021
- Hinweis: German version G 492
- Verkaufseinheit: 1
- Mindestabnahme: 1
- Artikel-Nr.: 512140
62,03 €*
This Technical Rule G 492 governs planning, manufacturing, assembly, testing, commissioning and operation, as well as decommissioning and disposal of gas measuring systems of up to 100 bar1 in gas transportation and distribution systems and stations supplying commercial, industrial, or other comparable facilities.
1 Scope of Application
2 Normative References
2.1 DVGW Sets of Rules
2.2 DIN Standards
2.3 International Standards
2.4 PTB Sets of Rules
2.5 Acts
2.6 Ordinances (national)
2.7 Ordinances (EU)
2.8 Other Regulations
3 Terms, Symbols, Units, and Abbreviations
3.1 System
3.1.1 Measuring System for the Determination of Gas Concomitant Substances
3.1.2 Measuring System for the Determination of Gas Quality
3.1.3 Gas Measuring Station
3.1.4 Mobile Gas Measuring Station
3.2 Pressure
3.3 Flow-Rates
3.3.1 Flow-Rate
3.3.2 Flow-Rate Qb
3.3.3 Maximum Flow-Rate Qb,max
3.3.4 Minimum Flow-Rate Qb,min
3.4 Standard System Operating Conditions
3.5 Personnel Qualification
3.5.1 Qualified Person (QP)
3.5.2 Expert / Technical Expert (TE)
4 Quality and Managements Systems
4.1 General
4.2 Tasked Companies
5 Influence on the Environment
6 Gas Measuring System Installation Space
6.1 General
6.2 Installation Location Layout
6.3 Safety of Installation Location
7 Housing and Casing
7.1 Housing Requirements
7.2 Explosion Protection
7.3 Fire Protection
8 System Design
8.1 General
8.2 Measuring Concept
8.2.1 General
8.2.2 Continuity of Gas Transportation
8.2.2.1 General
8.2.2.2 Availability
8.3 Components and Assemblies
8.4 Stress Analysis
8.4.1 Design Pressure
8.4.2 Supports and Support Structures
8.4.3 Temperature
8.4.4 Gas Velocity
8.5 Gas Meters
8.5.1 General
8.5.2 Displacement Meters
8.5.3 Velocity Meters
8.5.4 Differential Pressure Gas Meters
8.6 Flow Correctors / Conversion Devices Including Sensors
8.7 Recording Devices
8.8 Gas Quality Measuring Systems
8.9 Measuring Data Communication Systems
8.9.1 General
8.9.2 Communication System
8.10 Meter Run
8.11 Shut-off Devices Upstream of the Measuring System
8.12 Gas Meter Bypass Line
8.13 Monitoring Systems
8.14 Switchover Device for the Selection of the Suitable Meter Run
8.15 Flow Straighteners
8.16 Device for Dampening Pulsations and Vibrations.
8.17 Filter and Separator
8.18 Station Heating
8.19 Electrotechnical Devices
8.20 Conformity-assessed/Factory-tested Gas Pressure Regulations Upstream of Gas Meters
9 Overpressure Protection
10 Pre-Commissioning Testing
10.1 General
10.2 Testing of the Measuring System Assembly
10.3 Metrological Documentation
11 Commissioning
11.1 General
11.2 Process Commissioning
11.3 Metrological Commissioning
11.3.1 General
11.3.2 Testing Equipment for Instrumentation
11.3.3 Testing Measuring Systems
11.3.4 Functional Testing of Data Transmission
12 Operation, Maintenance
12.1 General
12.2 Display at the Installation Location
13 Decommissioning and Disposal
13.1 General
13.2 Decommissioning
13.3 Disposal
Annex A (informative) – Visual Examples for Gas Measuring Systems
Annex B (informative) – Part 1 Certificate for Expert Testing of Gas Measuring Systems as defined by Section 10 of DVGW Code of Practice G 492
Annex B (informative) – Part 2 Certificate for Expert Testing of Gas Measuring Systems as defined by Section 11 of DVGW Code of Practice G 492
Further Reading