GB/T 20603-2023Refrigerated light hydrocarbon fluids - Sampling for liquefied natural gas (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 replaces GB/T 20603-2006 "Continuous Sampling Method for Refrigerated Light Hydrocarbon Fluid Liquefied Natural Gas" and is consistent with GB/T 20603-Compared with:2006, in addition to structural adjustments and editorial changes, the main technical changes are as follows:

a) Added requirements for back-end devices for intermittent sampling and spot sampling (see 6.6 and 6:7);

b) Added sampling step requirements for intermittent sampling and spot sampling (see 7.2 and 7:3);

c) Added sampling reporting requirements for intermittent sampling and spot sampling (see 8.3 and 8:4):

Please note that some content in this document may be subject to patents: The publisher of this document assumes no responsibility for identifying patents:

1 Scope

This document specifies the sampling methods when liquefied natural gas (LNG) is transported through pipelines, including continuous sampling, intermittent sampling and spot sampling method:

This document is applicable to liquefied natural gas sampling at small LNG stations such as large LNG receiving stations, LNG factories, filling stations, and gas filling stations:

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text: Among them, the dated quotations for undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document:

GB/T 13609 Guidelines for natural gas sampling

3 Terms and definitions

The following terms and definitions apply to this document:

liquefied natural gas an inert gas consisting primarily of methane and may contain small amounts of ethane, propane, butane, nitrogen, or other components commonly found in natural gas:

Color cryogenic liquid fluid:

[Source: GB/T 8423.3-2018,2:1:14] 3.2 continuous samplingcontinuoussampling A sampling method that continuously removes samples from the sample source during the entire period of stable transportation:

intermittent samplingintermittentsampling A sampling method that draws gasified LNG at predetermined intervals or at predetermined flow intervals:

spotsampling

A sample of a specified volume is collected from the LNG flow path at a specified time and place:

subcooling

Lowers the temperature of LNG below its boiling point at a given pressure:

degreeofsubcooling

The enthalpy change of LNG from the boiling point to the subcooling point at a given pressure: