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 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.

The regulations in this Guideline G 451 shall be observed when planning and constructing gas transmission pipelines in conjunction with statutory procedures such as regional planning procedures und planning permission hearings.

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.

This Code of Practice G 265‑1 serves as a basis for designing, manu‑facturing, constructing, testing and commissioning plants for upgrading biogas to natural gas quality, plants for injecting these gases into gas transmission and distribution systems, and plants for the refeeding of gas into the upstream gas supply network. This DVGW Code of Practice provides a summary overview of the minimum requirements on the technical safety of plants and components required for the utilisation of biogas, from upgrading plants through to compressor stations; pressure control, href= https://shop.wvgw.de/509052 >here. the injection into the gas supply network as added or substitute gas. At the same time, one focus was on the indispensable coordination between the ? generally different ? plant operators.

This Code of Practice G 493‑1 serves as a basis for certifying and awarding the DVGW certification mark to specialised companies that design, manufacture and set up turn‑key gas pressure regulating and gas measuring stations. Quality, safety and security have always been given top priority by the gas industry, and this shall continue to be so in the future. Company certification is indispensable for meeting this goal; this 5th edition of this Code of Practice provides the basis for certification. This Code of Practice describes not only the qualification criteria to be met by the relevant companies but also ‑ and in some more detail ‑ the fields of work in which appointed experts have to demonstrate particular knowledge. The fact that the Energy Industry Act (EnWG) has now broadened the meaning of the term ?biogas? to include hydrogen from renewable sources has created new qualification requirements for appointed experts. These requirements shall be amended if, when and as href= https://shop.wvgw.de/508694 >here. requirements set forth in this Code of Practice are eligible for certification.