Detail of GB/T 18604-2014

Introduction of GB/T 18604-2014

1 Scope This standard specifies measuring performance requirements, meter body requirements, installation and maintenance, site verification testing requirement as well as flow calculation method and measurement uncertainty estimation of ultrasonic flow meters. This standard is applicable to plug-in gas ultrasonic flow meter (transit-time difference method, hereinafter referred to as flow meter) and is generally used for measurement of natural gas flow in gathering and transportation device, gas transmission line, storage facility, gas distribution system and user metering system. The use of jacket-type gas ultrasonic flow meter may also refer to this standard. 2 Normative References The following documents for the application of this document are essential. Any dated reference, only the edition cited applies. For the undated reference, the latest edition (including any amendments) applies. GB 3836.1 Explosive Atmospheres - Part 1: Equipment - General Requirements GB 3836.2 Explosive Atmospheres - Part 2: Equipment Protection by Flameproof Enclosures “d” GB 3836.4 Explosive atmospheres - Part 4: Equipment protection by intrinsic safety GB/T 4208 Degrees of Protection Provided by Enclosure (IP Code) ((IEC 60529) GB/T 11062-1998 Natural Gas - Calculation of Calorific Values, Density, Relative Density and Wobbe Index from Composition GB/T 13610 Analysis of Natural Gas by Gas Chromatography GB/T 17747(All parts) Natural Gas - Calculation of Compression Factor GB/T 21446-2008 Measurement of Natural Gas Flow by means of Standard Orifice Meter SY/T 0599-2006 Metallic Material Requirements on Resistance to Sulfide Stress Cracking and Stress Corrosion Cracking for Natural Gas Surface Equipment JJG 1030-2007 Ultrasonic Flowmeters IS0 5167-1: 2003 Measurement of Fluid Flow by Means of Pressure Differential Devices Inserted in Circular Cross-section Conduits Running Full - Part 1: General Principles and Requirements) AGA Report No.10 Speed of Sound in Natural Gas and Other Related Hydrocarbon Gases) 3 Quantities, Terms and Definitions 3.1 Quantities See Table 1 for names and symbols of quantities and units in this standard.

Contents of GB/T 18604-2014

Foreword i 1 Scope 2 Normative References 3 Quantities, Terms and Definitions 4 Measurement Principle 4.1 Basic Principle 4.2 Influencing Factors of Measuring Accuracy 5 Working Conditions 5.1 Natural Gas Quality 5.2 Pressure 5.3 Temperature 5.4 Flow Range and Flow Direction 5.5 Velocity Distribution 6 Measuring Performance Requirements 6.1 Requirements on Measuring Performance of Multi-path Gas Ultrasonic Flow Meter 6.2 Requirements on Measuring Performance of Single-path Gas Ultrasonic Flow Meter 6.3 Influence of Working Condition on Measuring Performance 7 Flow Meter Requirements 7.1 Composition and Basic Requirement 7.2 Meter Body 7.3 Ultrasonic Transducer 7.4 Electronic Part 7.5 Flow Rate Computer 8 Installation Requirement and Maintenance 8.1 Influence Factors against Installation 8.2 Pipe Arrangement 8.3 Maintenance 9 Requirements for Site Validation and Testing 9.1 Testing Content and Procedure 9.2 Testing Report 10 Flow Rate Calculation Method and Measurement Uncertainty Estimation 10.1 Flow Calculation in Standard Reference Conditions 10.2 Determination of Measured Flow in Standard Reference Conditions 10.3 Calculation of Flow in Working Conditions 10.4 Uncertainty estimation of flow measurement Annex A (Informative) Basic Principle Annex B (Normative) Flow Calibration of Metering Package Annex C (Normative) End-of-manufacturing Testing Requirements Annex D (Informative) Available Documents Annex E (Informative) Generation of Acoustic Noise and Control Measures Annex F (Informative) Performance Verification Test on Flow Meter and Flow Conditioner Annex G (Informative) Monitoring and Guarantee of Site Measuring Performance of Flow Meter