GB/T 13609-2025Natural gas - Gas sampling (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

Drafting.

This document supersedes GB/T 13609-2017 "Guidelines for Natural Gas Sampling". Compared with GB/T 13609-2017, except for structural adjustments and revisions...

Aside from the logical changes, the main technical changes are as follows.

a) The description of pressure in the scope has been removed (see Chapter 1 of the 2017 edition);

b) The terms "absorption," "adsorption," "pollutant," "desorption," "sampling location," and "sampling site" have been added (see 3.1, 3.2, 3.3, 3.4, 3.18).

3.20);

c) The terms "flow ratio accumulator sampler", "liquid separator", "low-pressure natural gas", "transmission conduit", and "water dew point" have been removed (see 2017 edition).

(2.3, 2.8, 2.9, 2.19, 2.20)

d) Safety precautions have been added (see Chapter 4);

e) Sampling principles have been added (see Chapter 5);

f) A representative sample was added (see Chapter 6);

g) Increased sampling locations (see Chapter 8);

h) Added general requirements (see 9.1), precautions for adsorption of sampling equipment (see 9.2.3), equilibration of sampling equipment (see 9.2.4), and delay.

Time (see 9.7);

i) A concentration unit was added (see 10.13);

j) The number and order of the equipment have been increased (see 10.14);

k) Added system verification (see Chapter 11);

l) Added troubleshooting (see Chapter 12).

This document is modified to adopt ISO 10715:2022 "Natural gas sampling".

This document has undergone the following structural adjustments compared to ISO 10715:2022.

a) Requirements related to the heat preservation and pressure-holding sampling method have been added (see 7.2.8), and the subsequent chapter numbers will be adjusted accordingly;

b) Requirements for gas sampling bags have been added (see 10.12.4), and subsequent chapter numbers will be adjusted accordingly;

c) The order of the appendices has been adjusted according to the order in which they appear in the main text.

The technical differences between this document and ISO 10715:2022, and the reasons therefor, are as follows.

a) ISO 14532 (see Chapter 3) has been replaced with the normatively referenced GB/T 20604 to adapt to my country's technical conditions and improve standards.

Quasi-applicability;

b) The terms "gas adsorption effect," "liquid separator," "trace components," and "wet surface" have been removed (see section 3.7 of ISO 10715:2022).

3.12, 3.24, 3.26);

c) The requirements for safety precautions have been changed (see Chapter 4 of ISO 10715:2022);

d) Added "7.2.8 Sampling Method Based on Insulation and Pressure" to adapt to the actual sampling needs of natural gas production in my country and improve standard operating procedures.

Actual nature;

e) Added "10.12.4 Gas Sampling Bag" to meet the actual needs of sample containers for natural gas sampling in my country and improve standard operating procedures.

Acting.

The following editorial changes have been made to this document.

a) Move "Note 2.'Sampling location' is not defined the same as 'sampling point' or 'sampling position'" in 8.4 to "Note. 'Sampling location' is defined differently from 'sampling point' or 'sampling position'" in 3.2.

The definitions of 'location', 'sampling point', and 'sampling location' are not the same.

b) The numbering of terms and definitions has been corrected; ISO 10715:2022 does not include 3.25.

c) Added "B.5 Sampling procedure using heat preservation and pressure preservation method".

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed and is under the jurisdiction of the National Technical Committee on Standardization of Natural Gas (SAC/TC244).

1 Scope

This document describes a sampling method for obtaining representative natural gas samples, including natural gas delivered to the gas transmission and distribution network.

and natural gas substitutes.

This document applies to on-site sampling of natural gas. The obtained samples are used to measure and monitor the gas interchangeability and energy of the gas entering the pipeline network.

It is applicable to sampling at cross-border and trade-transfer metering stations. This document applies only to dry natural gas (single-phase, i.e., typically transported via natural gas pipelines).

Sampling of the transported gas.

This document does not apply to moisture (two-phase or three-phase) sampling.

Note 1.This document does not cover safety issues related to gas sampling.

Note 2.This document takes into account sampling of specific gases, see Appendix A.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 20604 Natural Gas Vocabulary

3 Terms and Definitions

The terms and definitions defined in GB/T 20604 and the following terms and definitions apply to this document.

absorption

When a gas mixture comes into contact with a liquid, one or more components are extracted from the gas.

Note 1.During the absorption or extraction process, the absorbent material will undergo (or be accompanied by) some physical and/or chemical changes.

Note 2.Gas components are retained due to capillary action, osmosis, chemical action, or dissolution. For example, water is removed from natural gas using glycol (ethylene glycol).

adsorption

Using physical or chemical forces to retain gas molecules, dissolved substances, or liquids on the surface of a solid or liquid in contact with them.

Example. Retention of carbon in methane.

pollutant

Components such as particulate matter, ethylene glycol, and compressor oil, which are present in very low concentrations, are considered interfering components and are not part of the gas to be sampled.

Note 1.Contaminants are generally harmful to analytical equipment. If contaminants enter the sampling process, they must be removed from the sample before entering the analytical unit.

Once contaminants enter the sampling process, they will continue to affect any subsequent samples that come into contact with them. Over time, the contaminants in the sampling system will...

The accumulation of contaminants can affect the sample, making it no longer representative.

Note 2.Do not confuse contaminants with the inherent trace components of the gas being sampled.