G 407 Technical Information - Guideline 08/2022

Conversion of Gas Pipelines made of Steel Pipes for the Distribution of Hydrogen - containing High-Methane Gases and Hydrogen up to 16 bar Operating Pressure

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  • DVGW
  • 19 pages
  • only as PDF available
  • 1st edition 2022
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  • 512320

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).


1 Scope of Application

2 Normative References

3 Terms, Symbols, Units and Abbreviation

3.1 Conversion

4 Grading of Networks and Recommended Actions for the Conversion of Networks

4.1 General

4.2 Grading Networks With Consideration Towards Hydrogen Concentration and Maximum Operating Pressure (MOP)

4.3 Recommended Actions for Grading and Evaluating Steel Gas Pipelines for the Operation with Hydrogen-containing, Methane-rich Gases or Hydrogen up to 16 Bar.

5 Documentation Concerning Construction, Operation, and Maintenance

5.1 General

5.2 Construction, Operation, and Maintenance Documents

6 Construction Elements and Components

6.1 General

6.2 Declaration of Conformity / Manufacturer Certificate 6.3 Flow Controllers in Service Lines

7 Hydrogen Compatibility of the Gas Pipeline

7.1 General

7.2 Pressure Testing of Buried Pipelines

7.3 Odorization

7.4 Commissioning

7.5 Test Certificate

7.6 Operation

Annex A (informative) – Specific Gas Values of Methane-Hydrogen Mixtures Annex B (normative) – Fracture Mechanics Testing of Steel Pipelines < 16 With Regard to Hydrogen

B.1 General

B.2 Input Variables for the Analysis of Fracture Mechanics Using Barlow’s Formula

B.2.1 Determining Operating Pressure 𝑂𝑂𝑂𝑂 in bar

B.2.2 Determining the Outside Pipe Diameter 𝐷𝐷 in mm

B.2.3 Type of Material und Minimum Yield Strength 𝑅𝑅𝑅𝑅0.5 N/mm²

B.2.4 Capacity Factor 𝑓𝑓0 B.2.5 Determining the Actual Pipe Wall Thickness 𝑇𝑇 in mm

B.3 Determining the Existing Safety Factor