GB/T 21391-2008Measurement of natural gas flow by turbine meter (English PDF)

Foreword

This standard is non-equivalent to the European standard EN 12261.2002 "Gas

flow meter - gas turbine flow meter", makes reference to AGA No.7.2004

"Measurement of fuel gas by turbine meters", ISO 9951.1993 "Measurement of

gas flow in closed conduits - Turbine meters", and JJG 198-1994 "Verification

regulation of velocity flow meter", AND is, combining with the actual

requirements for local use, added with the standard reference conditions for the

calculation of natural gas volume and calorific value, the explosion proof

requirements for using turbine meter to measure the natural gas flow, the

requirements for integrated intelligent flow meter, the calculation for using

turbine meter to measure the natural gas flow, the calculation of compression

factor, the estimation of uncertainty, real-flow calibration, and the application

after calibration, and the other technical provisions.

The main differences between this standard and EN 12261.2002 are as follows.

- ADD Chapter 4 "Measurement principles", Chapter 6 "Flow meter

requirements", Chapter 7 "Installation requirements, use and maintenance",

and Chapter 8 "Flow calculation methods and measurement uncertainty

estimation";

- ADD Appendix B "Additional performance characteristics of the flow meter",

Appendix C "Field test of flow meters", and Appendix D "Example of natural

gas flow calculation".

- DELETE Chapter 4 "Flow meter classification" and some contents on type

tests from Chapter 5 and 6 of EN 12261;

- MODIFY some of the statements that apply to international standards into

the statements applicable to Chinese standard.

Appendix A to this standard is a normative appendix.Appendix B, Appendix C

and Appendix D are informative.

This standard was proposed by China National Petroleum Corporation.

This standard shall be under the jurisdiction of the Oil & Gas Measurement and

Analysis Method Professional Standardization Technical Committee.

The responsible drafting organizations of this standard. National Crude Oil Flow

Measurement Station Chengdu Natural Gas Flow Substation.

The participating drafting organizations of this standard. China Petroleum

Southwest Oil and Gas Field Branch.

Measurement of natural gas flow by turbine meters

1 Scope

This standard specifies the measurement conditions, requirements,

performance, installation, real-flow calibration and field inspection of gas turbine

flow meter (hereinafter referred to as flow meter) for natural gas flow

measurement.

The natural gas component measured by the flow meter shall be within the

range specified in GB 17820-1999, GB/T 17747.1-1999, GB/T 17747.2-1999

and GB/T 17747.3-1999, AND the true relative density of natural gas is 0.55 ~

0.80.

This standard specifies that the standard reference conditions for the

measurement of natural gas flow and the combustion standard reference

conditions for the calorific value measurement are absolute pressure Pn =

2 Normative references

The provisions in following documents become the provisions of this Standard

through reference in this Standard. For the dated references, the subsequent

amendments (excluding corrections) or revisions do not apply to this Standard;

however, parties who reach an agreement based on this Standard are

encouraged to study if the latest versions of these documents are applicable.

For undated references, the latest edition of the referenced document applies.

GB 3836.1-2000 Explosive atmospheres - Part 1.Equipment - General

requirements (eqv IEC 60079-0.1998)

GB 3836.2-2000 Electrical apparatus for explosive gas atmospheres - Part

2 Flameproof enclosure d (eqv IEC 60079-1.1990)

GB 3836.4-2000 Electrical apparatus for explosive gas atmospheres - Part

4 Intrinsic safety i (eqv IEC 60079-11.1999)

GB/T 4208 Degree of protection of enclosure (IP code)

GB/T 11062-1998 Natural gas - Calculation of calorific values, density,

relative density and Wobbe index from composition (neq ISO 6976.1995)

GB/T 13610-2003 Analysis of natural gas by gas chromatography

GB/T 15464 General purpose specification for the packaging of

instrumentation products

GB/T 17747.1-1999 Natural gas - Calculation of compression factor - Part 1.

Introduction and guideline (eqv ISO 12213-1.1997)

GB/T 17747.2-1999 Natural gas - Calculation of compression factor - Part 2.

Calculation using molar (eqv ISO 12213-2.1997)

GB/T 17747.3-1999 Natural gas - Calculation of compression factor - Part 3.

Calculation using physical properties (eqv ISO 12213-3.1997)

GB 17820-1999 Natural gas

GB/T 18603-2001 Technical requirements for measuring systems for natural

gas

GB/T 18940-2003 Measurement of gas flow in closed conduits - Turbine

meters (ISO 9951.1993, IDT)

JJG 198 Verification regulation of velocity flow meter

SY/T 6143-2004 Measurement of natural gas flow with standard orifice flow

meter

3 Terms, definitions and symbols

The following terms and definitions apply to this standard.

3.1

Turbine gas meter

It refers to the metering equipment for which the rotation speed and gas

volume flow are in functional relationship when the impeller rotates under the

effect of gas flow. The gas volume flow passing through the flow meter is

obtained based on the number of impeller rotations.

3.2

Rangeability

6 Flow meter requirements