Provides basic requirements for diaphragm gas meters under tender, to ensure optimum performance, both, when purchased, and after extended service; and to satisfy the requirements of statutory authorities after due consideration is given to variations in accuracies of meter testing. Covers the working environment, materials of construction and performance required of diaphragm meters of Qmax up to 8 m3/h when tested at standard conditions (MSC) on air.
Table of contents
Header
About this publication
Preface
1 Scope and general
1.1 Scope
1.2 Referenced documents
1.3 Definitions
2 Working environment
2.1 Gas type
2.2 Temperature
2.3 Working pressure
2.4 Mounting
3 Meter construction
3.1 Materials of construction
3.1.1 General
3.1.2 Metal castings
3.1.3 Case jointing materials
3.1.4 Valve covers and grids
3.1.5 Sealing glands
3.1.6 Diaphragms
3.1.7 Gearing
3.1.8 Solder
3.1.9 Plastic components
3.1.10 Resistance to exposure to solar radiation and weathering
3.1.11 Miscellaneous components
3.1.12 Meter connections
3.1.13 Reverse flow devices
3.1.14 Pressure measuring point
3.1.15 Sealing of meters
3.1.16 Protection of interior of meters
3.1.17 Bearings
3.1.18 Entrained solids
3.1.19 Uniformity of meters
3.2 Mechanical strength
3.3 Heat resistance
3.4 Meter index
3.4.1 General
3.4.2 Proving dial or proving drum
3.4.3 Electromechanical or electronic indicating devices
3.4.4 Electrical devices
3.4.5 Pulse outputs
3.4.6 Index housing
3.4.7 Magnetic coupling index drive
3.5 Labelling meters
3.6 Records
4 Performance
4.1 Test medium
4.2 Initial performance
4.3 In-service performance
4.4 Noise in operation
4.5 Recording of test results
5 Routine testing and inspection
5.1 Tests to be conducted
5.1.1 Test environment
5.1.2 Performance tests
5.1.3 Case soundness
5.2 Durability tests
5.3 Test result uncertainty
5.3.1 General
5.3.2 Uncertainty contributors
5.3.3 Accuracy test uncertainty
5.3.4 Determining compliance
5.3.5 Laboratory comparisons
Appendix A
A1 Scope
A2 Principle
A3 Apparatus
A4 Frequency of testing
A5 Procedure
A5.1 General
A5.2 Rigidity test
A5.3 Impact test
A5.4 Flammability test (from UL94)
Appendix B
B1 Scope
B2 Principle
B3 Apparatus
B4 Frequency of testing
B5 Procedure
Appendix C
C1 Scope
C2 Principle
C3 Apparatus
C4 Reagents
C5 Frequency of test
C6 Procedure
Appendix D
D1 Scope
D2 Principle
D3 Apparatus
D4 Frequency of testing
D5 Procedure for meter case distortion test
D6 Procedure for meter case and connection rigidity test
