Content of DVGW Information GAS No. 29 This DVGW Information GAS No. 29 provides an overview of the requirements that must be met for the use of hydrogen in systems for the pipeline-bound supply of the general public and the connected gas applications so that these can be labelled "H2-ready".  In this DVGW Information GAS No. 29, a model is proposed to visualise the different levels of assessment in order to classify statements on the readiness of infrastructures for the grid-based supply of hydrogen. The term "H2-ready" is used to describe this readiness for hydrogen use, which is explained in the respective context in this DVGW Information GAS No. 29.  The proposed model can also be applied analogously to new or existing plants for operational self-supply in which hydrogen is to be used, taking into account the specific legal requirements.  Safe operation with the hazardous substance natural gas is already guaranteed for gas supply networks and gas applications. If a natural gas network is converted into a hydrogen network, the same level of safety can be guaranteed if the DVGW Codes of Practice applicable to hydrogen are taken into account - without prejudice to other legal requirements. Table of contents Foreword 1 Scope 2 DVGW Codes of Practice 3 Terms and definitions 4 Model for the application of the term "H2-ready" 5 Assessment of the gas infrastructure and gas applications   Anhang A - Overview of important DVGW Set of Rules and the supporting H2 guidelines Bibliography German version DVGW-Information GAS Nr. 29 Buy DVGW Information GAS No. 29 You can purchase DVGW Information GAS No. 29 as PDF file for immediate download. 

Content of DVGW Guideline G 404 DVGW Guideline G 404 introduces provisions for the technical reduction of emissions in the Gas Infrastructure. Many of the measures listed in this DVGW-Guideline G 404 have already been used in the gas infrastructure for years for safety reasons, but if applied promptly, they also lead to a reduction in emissions and thus make an important contribution to environmental relief. The main measures used in practice are listed in G 404. According to the current state of knowledge, these can also be used in networks for hydrogen-containing methane-rich gases (2nd gas family) and for hydrogen (5th gas family) in accordance with DVGW Code of Practice G 260. The German gas network consists of different materials and nominal diameters and already has very low methane emissions. In particular, the constantly updated requirements from the DVGW regulations regarding maintenance have led to a continuous reduction in methane losses in the German gas industry in recent years.Methane emissions have various natural and man-made sources. They account for a total of 6 % of all green-house gases in Germany, which are mainly produced in agriculture and waste management, but also partly in the energy industry using coal, oil and natural gas. According to the current status, the German gas infrastructure accounts for methane emissions, which correspond to 0.08 % of the total anthropogenic greenhouse gas emissions in Germany of 760 million tonnes of CO2 equivalent in 2021. These arise from the transport and distribution of methane-rich gas and are to be further reduced through technical measures. Table of contents Foreword 1 Scope 2 Normative references 3 Terms, symbols, units and abbreviations 4 Types of gas emissions 5 Localisation of gas emission sources in the gas infrastructure 6 Measures to reduce gas emissions in the gas infrastructure References Important normative references DVGW Code of Practice G 260 DVGW Code of Practice G 265-2 DVGW Code of Practice G 441 DVGW Guideline G 452-1 DVGW Code of Practice G 465-2 DVGW Code of Practice G 491 DVGW Code of Practice G 600 DVGW Code of Practice GW 10 DVGW Guideline GW 18 DVGW Code of Practice GW 27   Buy DVGW Guideline G 404 You can purchase DVGW G 404 Guideline as PDF file for immediate download. 

This DVGW-Information GAS No. 17 provides information on how to implement the lightning protection requirements in accordance with IEC 62305 for systems of gas and hydrogen transport and distribution systemas well as for systems supplying commercial, industrial or comparable facilities. Lightning protection measures are used to protect people, structures and technical equipment against the effects of lightning.

This Guideline G 464 shall apply for the fracture mechanical assessment of steel gas pipelines that already exist or are projected for construction with a design pressure of more than 16 bar for the transportation or distribution of gases of the 5th gas family (hydrogen) as specified by DVGW Code of Practice G 260. This present Guideline G 464 addresses the assessment of an assumed defect; for the assessment of measured defects, the guideline can be applied analogously.

This guideline G 408 shall apply to the conversion of pipelines made from plastic to hydrogen-containing, methane-rich gases (2nd gas family) or hydrogen (5th gas family) in accordance with DVGW Code of Practice G 260 up to an operating pressure of 16 bar and ends with the main shut-off valve, the thematic threshold to DVGW Guideline G 655. This guideline G 408 can also be applied to the conversion of plastic gas pipeline operated with gases that do not conform to the specifications of DVGW Code of Practice G 260 if the gases’ specific characteristics and, if applicable, other existing regulations are taken into account. The respective guidelines on pipeline conversion shall be consulted for networks using different pipeline materials (e.g., plastic and steel).

This guideline G 407 shall apply to the conversion of pipelines made from steel to hydrogen-containing, methane-rich gases (2nd gas family) or hydrogen (5th gas family) in accordance with DVGW Code of Practice G 260 up to an operating pressure of 16th and ends with the main shut-off valve, the custody transfer point to DVGW G 600 (A), respectively to G 614.1 (A) (including the additions detailed in DVGW Guideline G 655). This guideline can also be applied to the conversion of steel gas pipeline operated with gases that do not conform to the specifications of DVGW Code of Practice G 260 when taking into account the gases’ specific characteristics and, if applicable, other existing regulations. The respective guidelines on pipeline conversion shall be consulted for networks using different pipeline materials (e.g., plastic and steel).

For hydrogen transmission within the German gas grid, it is imperative to obtain a clearly defined assessment of steel components for hydrogen suitability and relevant implementation in the DVGW Codes of Practice. Within this context, DVGW Code of Practice G 409 (for the conversion of pipelines to hydrogen transmission) and DVGW Code of Practice G 463  (for the construction of new pipelines), for example, have been specifically aligned to hydrogen as a transmission medium. Both these codes of practice may require a fracture-mechanical assessment of pipelines and pipeline components, with fracture-mechanical parameters beingrequired as input variables. So far, it was only in ASME B 31.12 [3] that these parameters were specified in an international code of practice. They specifically involve minimum fracture toughness (KIc) and the description of crack toughness (da/dN) with hydrogen as a medium. However, the parameters specified in ASME B 31.12 were based on investigations on US materials which are verysimilar, but not identical, to the materials used in Germany and elsewhere in Europe. Furthermore, the conversion of existing older natural gas pipelines (comprising older materials) is of very considerable interest particularly for the scope of application of the DVGW Code of Practice, although a direct transferability of the US investigations was considered to be problematic. Hence, within the context of the DVGW’s extensive SyWeSt H2 research project, fracturemechanical investigations were performed specifically for the pipeline steel grades used in Germany (and, in some cases, elsewhere in Europe) with hydrogen as a medium. The objective of this project was to compare the established fracture-mechanical parameters with the results on which ASME B 31.12 is based for the purpose of validating their application to steel grades used in Germany and, where applicable, drawing up a modified correlation for crack growth.

In recent years, the relevant DVGW Codes of Practice and associated information sheets for carrying out and evaluating the above-ground inspection of natural gas pipelines have been revised. In addition, measurement technology and data processing (digitisation) have developed constantly. For the above-ground inspection of buried pipelines in the distribution network through inspections and drives, new measurement methods are increasingly being used. In the EvaNeMeL research project, these new measurement methods were evaluated both theoretically and through experimental investigations. Five vehicle-mounted measurement systems and three hand-held remote gas detection methods were investigated. The results demonstrate the performance of the novel methods against a benchmark and also to serve as a basis for a subsequent supplement to the DVGW rules and regulations for above-ground inspection. The benchmark was an experienced “Gasspuerer” (gas safety personnel) who carried out a walk-through with a probe-based PortaFID M3K in parallel to the experimental investigations. This established walk-through of buried pipelines results in a high level of safety for the public gas supply.

In conjunction with DIN EN 1594, this Technical Rule G 463 applies to the planning and construction of steel high pressure gas pipelines with a design pressure of more than 16 bar for supplying gas to the general public as well as to connected energy facilities on company premises and in the field of commercial gas application of gases of the 2nd and 5th gas family as defined by DVGW Code of Practice G 260. The scope of application has no upwards limitation in terms of the technical parameters nominal diameter and design pressure. This Technical Rule can be applied mutatis mutandis to the construction of high pressure gas pipelines which do not conform to the specifications of DVGW Code of Practice G 260, provided that the specific characteristics of the gases or, if applicable, other already existing technical sets of rules are taken into account.

The DVGW set of rules G 414 for the installation (planning, building and commissioning) of gas pipework focuses on buried gas pipework; it contains only few instructions to be observed when installing above-ground gas pipework.

This standard G 493-2 encompasses personal and professional requirements for companies providing maintenance for gas plants and installations that fall within the scope of DVGW G 495 (A), as well as biogas injection and refeeding plants as specified by DVGW G 265-2 or hydrogen injection plants as specified by DVGW G 265-4 (M).Companies which, within the context of comprehensive plant management, either as original operators or as contractors, are responsible for the maintenance of energy plants, and possess the required personal qualification and organization according to DVGW G 1000 (A), may conduct the maintenance of gas plants without certification as defined by this standard within the network which they have the abovementioned responsibility for. The prerequisite for the maintenance without certification as mentioned above is that the expert and tech-nical conditions detailed in this standard are met by the company’s own workforce or by service providers with a TSM certification or other corresponding certifications. The company shall appoint the experts re-sponsible for maintenance in writing. The fulfilment of these conditions can be verified e.g. during a TSM review according to DVGW G 1000 (A).

This Technical Rule G 492 governs planning, manufacturing, assembly, testing, commissioning and operation, as well as decommissioning and disposal of gas measuring systems of up to 100 bar1 in gas transportation and distribution systems and stations supplying commercial, industrial, or other comparable facilities.

Code of Practice GW 315 provides essential information on how to avoid damaging to existing supply systems during construction operations. It applies to all construction work  and regulates the requirements for construction contractors and operators of supply systems.

This document ISO 17885 specifies the requirements for mechanical fittings for joining plastic piping systems for the supply of gaseous fuels, the supply of water for human consumption and other purposes, as well as for industrial application. It provides a unified set of test methods to check the performance of the fittings, depending on their intended use. It is the responsibility of the purchaser or specifier to select the appropriate fitting, taking into account their particular requirements and any relevant national guidance or regulations and installation practices or codes.

This Technical Rule G 260 specifies the requirements for the quality of fuel gases used in the supply of the general public with gas and sets the parameters for gas delivery, gas transportation, gas distribution, gas storage, operation of gas plants/systems and gas appliances for commercial and industrial gas applications as well as for development, standardization, and testing. Gases transported in separate pipelines which are not used in the supply of the general public, or are used as energy carrier or resource, and/or are used in special gas appliances are not subject to the scope of this Technical Rule.

G 452‑3 Technical Information ‑ Guideline 03/2021