DVGW GW 9 A 2011-05 PDF

Full title and description

STB DVGW GW 9 A 2011-05 — Code of practice (DVGW GW 9) for the evaluation of soils in view of their corrosion behaviour towards buried pipelines and tanks made of unalloyed and low-alloy ferrous materials. This document gives a soil-assessment method, measurement parameters and a scoring system to estimate corrosion loads and to support decisions on coatings, cathodic protection and other mitigation measures.

Abstract

The standard describes procedures for sampling and testing soils, defines key soil parameters (electrical resistivity, pH, moisture, buffer capacity, sulphate/salt content, presence of sulphate-reducing bacteria, groundwater conditions and soil homogeneity) and a modular scoring (Z‑parameters) approach to classify corrosion risk for buried unalloyed/low-alloy iron pipelines and tanks. It is intended to inform protective measures (coatings, selection of materials, cathodic protection) and to provide a consistent basis for site evaluations.

General information

• Status: Superseded (original DVGW GW 9:2011 edition; later revised—current technical rule published 2021).
• Publication date: Edition identifier in the title: 2011-05 (commonly cited as DVGW GW 9:2011; some catalog records show publication metadata around 2011–2013).
• Publisher: Deutscher Verein des Gas- und Wasserfaches (DVGW) / published by Wirtschafts- und Verlagsgesellschaft Gas und Wasser for DVGW rules.
• ICS / categories: Primary classification: 77.060 (Corrosion of metals). Relevant secondary classification: 23.040 (pipeline components and buried pipelines).
• Edition / version: DVGW GW 9 (2011) — often referenced as GW 9 A 2011-05; the DVGW rule was updated and reissued as DVGW GW 9:2021-08.
• Number of pages: Typical DVGW/GW technical-rule editions of this topic are compact (around 20–25 pages); the 2021 revision is published as 22 pages (the 2011 PDF editions are of similar length depending on language/format).

Scope

This Arbeitsblatt applies to the assessment of corrosive influences of soils on buried unalloyed or low-alloy iron and steel pipelines and stationary tanks. It covers sampling strategy, laboratory and in-situ measurements, parameter evaluation (Z‑parameter matrix) and gives guidance on interpreting results to determine expected corrosion loads and the need for protective measures. It does not replace detailed design rules for coatings or cathodic protection systems but provides the soil-evaluation input those designs require.

Key topics and requirements

• Soil sampling methods and sampling locations (horizontal and vertical homogeneity considerations).
• Measurement and evaluation of electrical soil resistivity (cell method and in-situ), moisture content and water table influence.
• Soil chemistry: pH, acid/alkaline buffering capacity, chloride and sulphate (neutral salts), sulphide content and microbiological concerns (sulfate-reducing bacteria).
• Use of a Z‑parameter scoring system (modules and numerical ratings) to estimate corrosion burden and classify site severity.
• Guidance on interpreting scores to recommend coatings, selection of materials and cathodic protection needs.
• Reporting requirements and how to integrate soil-assessment results into pipeline/tank protection planning.

Typical use and users

Engineers, corrosion specialists, geotechnical consultants, pipeline designers and asset owners/operators (gas and water utilities, pipeline contractors, infrastructure owners) use this standard to evaluate site-specific corrosion risk for buried steel structures and to provide quantified input for protection measures and maintenance planning. Regulatory bodies and inspection authorities may reference it when assessing compliance or risk.

Related standards

Commonly cited alongside DVGW GW 9 are national and international standards on cathodic protection, soil testing and corrosion terminology (for example DIN EN/ISO standards on corrosion terminology and cathodic protection and related DVGW/GW rules such as GW 10). Standards that use or reference GW 9 scoring appear in guidance for pipeline construction and corrosion risk assessment (DIN and EN documents frequently cross-reference GW 9 parameters).

Keywords

corrosion assessment; soil evaluation; buried pipelines; DVGW GW 9; Z-parameters; soil resistivity; pH; sulphates; cathodic protection; coatings; pipeline corrosion risk.

FAQ

Q: What is this standard?

A: It is DVGW Arbeitsblatt GW 9 (edition referenced as 2011-05 in many catalogs), a code of practice for evaluating soils with respect to their corrosion behaviour toward buried unalloyed and low-alloy iron pipelines and tanks.

Q: What does it cover?

A: It covers soil sampling, laboratory and in-situ measurements (resistivity, pH, moisture, salts, sulphides, buffer capacity, groundwater conditions), a Z‑parameter scoring scheme to assess corrosion load, and guidance for applying the results to protective measures (coatings, cathodic protection).

Q: Who typically uses it?

A: Corrosion engineers, geotechnical labs, pipeline designers, utility operators and contractors performing pre-construction site assessments or condition evaluations for buried steel infrastructure.

Q: Is it current or superseded?

A: The 2011 edition is superseded by a revised DVGW GW 9 issued in 2021 (DVGW GW 9:2021-08). Users should refer to the 2021 revision for the current technical rule; the 2011 edition remains useful for historical reference and where specifically cited.

Q: Is it part of a series?

A: Yes — GW-series DVGW Arbeitsblätter cover gas/water pipeline and corrosion-related topics (e.g., GW 10, GW 302 series). GW 9 is part of that set of technical rules addressing protection and assessment of buried metallic infrastructure.

Q: What are the key keywords?

A: Corrosion, soil assessment, buried pipelines, soil resistivity, pH, sulphates, Z-parameter, DVGW GW 9, cathodic protection, coatings.