Gas systems
As a generally recognised rule-setter in public gas supply, the DVGW has formulated the technical requirements for access to gas networks.
The safety of gas installations requires special attention. The DVGW rules and regulations ensure that the generally recognised rules of technology are applied in practice and that a high level of safety is ensured.
The pipelines of the gas network must be maintained at regular intervals and, if necessary, rehabilitated. You will find DVGW codes of practice and standards on all these topics in this section.
This document DIN CEN TR 17797 is written in preparation of future standardization and provides guidance on how injection of H2 into the gas infrastructure can impact processes from the input of gas into the on-shore transmission network up to the inlet connection of gas appliances.
This Technical Rule G 459‑2 applies to the design, installation, testing, commissioning, operation and maintenance of gas pressure regulating systems within the scope of DVGW Standard G 459‑1 with inlet pressures up to 5 bar1 and a maximum nominal flow rate of 200 m3/h under normal conditions for the supply of residential and office buildings, council housing as well as mixed‑use buildings and buildings housing public, cultural and commercial facilities to the extent that these are comparable to buildings of residential use with gases whose properties meet the requirements of DVGW Standard G 260, with the exception of liquefied petroleum gas (LPG)2, and which are supplied by public gas utilities. This Standard does not cover industrial production plants.
This Standard shall also apply, mutatis mutandis, to gas mixing plants that supply process gas to trade and industry and to industrial gas mixing plants for in‑house mixed‑gas supply.Gas mixing plants are frequently integrated into gas measurement and pressure reduction stations, which latter shall meet the specifications of DVGW Standards G 491 and G 492. In other words, most of the requirements specified in these Standards will also apply to gas mixing plants. All other requirements that go beyond the scope of G 491 and G 492 are described in this Technical Rule at hand, which first and foremost complements DVGW Standard G 491.
This DVGW Standard can be used as a guideline as it summarises the minimum requirements specified in the DVGW Sets of Rules that shall be observed by design firms, specialist contractors, operators and the involved authorities during the design, construction and operation of gas pipework for the transmission of untreated or partially treated biogas. The clause on Design also draws attention to the fact that the pertinent approvals and / or permissions shall be obtained prior to the start of construction of pipework planned to cross e. g. water bodies, roads and railways.Gases produced by fermentation processes such as e. g. biogases obtained from agriculture that are generally used to meet internal requirements and / or to power decentralised systems such as e. g. combined heat and power plants, are untreated or partially treated biogases that are not considered gases in accordance with DVGW Standard G 260.Nonetheless, the documents that form part of the DVGW Set of Rules that are referred to in this Standard shall also be applied to pipelines that transmit untreated or partially treated biogas.
The aim of this Standard GW 368 is to determine the lengths of pipeline to be locked against longitudinal forces.The Worksheet applies to ductile cast iron and steel pipes, fittings and valves. In principle, the formulaic correspondences described can also be applied to pipes in other materials. However, the properties of the other materials must be taken into account in each case, particularly specific weight and friction coefficient.
The Instruction Bulletin G 501 defines the requirements and test criteria applying to remote gas detection integrated aboard aircraft (helicopters or airplanes) and designed to aerially monitor both buried natural gas transmission pipelines as well as above ground natural gas transmission pipelines that are suited for airborne remote gas detection, both inside and outside built‑up areas. Portable hand‑held measuring instruments or methods combined with motor vehicles shall not be dealt with in this paper, as due to their flat observation angle to the surface compared to detection from the air they are subject to modified requirement criteria.
This Code of Practice G 402 has been elaborated by the G 401 project group within the Technical Committee on Gas distribution. It shall serve as a basis for the collection and evaluation of data to devise maintenance strategies for gas distribution systems. Maintenance comprises inspection as well as service and repair activities. The respective DVGW Codes of Practice define the fundamental principles applying to inspection and service activities. This Code of Practice G 402 focuses on the collection and evaluation of data that form the main basis for repair planning. The requirement for gas distribution systems to be permanently kept in a condition guaranteeing their technical safety and reliability necessitates timely and ongoing maintenance and service activities. These activities shall be planned in advance. Maintenance strategies shall be integrated into corporate processes, the collection of major grid data being a prerequisite for introducing such strategies. Beyond this, condition‑based maintenance requires ascertaining and evaluating grid conditions by means of adequate systems. This Code of Practice describes the fundamental procedure for ascertaining, collecting and evaluating maintenance‑relevant data and offers examples illustrating how to prepare and evaluate them.