ISO/NP TS 19875-1

Hydrogen technologies — Gas transmission pipelines — Part 1: Methodology for repurposing natural gas pipelines for transportation of hydrogen-blended natural gas up to 10% of hydrogen by volume

Scope

This document outlines the general principles, classification and evaluation process including pre-screening, component level assessment and system level assessment for re-purposing natural gas transmission pipeline systems with hydrogen blending.

Prior to the introduction of hydrogen into natural gas pipelines, it is essential to evaluate the compatibility of these pipelines to hydrogen. This document provides evaluation recommendations, taking into account the susceptibility of pipeline materials to hydrogen embrittlement, the potential risks associated with hydrogen leakage, and the explosion hazards posed by leaks of hydrogen-enriched natural gas. The assessment covers pipeline material, station equipment and instruments in the pipeline system such as meters, valves, fittings, and seals.

The assessment should be tailored based on the specific conditions of the hydrogen blending gas source, the operational pressure of the pipeline, and the grade of pipeline steel. This document intends for pipelines with a hydrogen blending ratio of 10% vol. or less. For an operating pressure of 7MPa or less, or a pipeline steel grade of X52 (L360) or lower, a prescriptive-based assessment is recommended. Conversely, for pipelines with an operating pressure greater than 7MPa after hydrogen blending, or a pipeline steel grade above X52 (L360), performance-based assessment strategies are recommended.

Although primarily intended for re-purposing existing natural gas pipelines with a blending ratio of less than 10% vol., this document may be referred to for a blending ratio over 10% vol. for cases where standards for higher blending ratios do not exist.