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Title / Design a cathodic protection system in a gas distribution network
Level / 6 / Credits / 12
Purpose / People credited with this unit standard are able to demonstrate knowledge of cathodic protection systems in a gas distribution network, and produce design specifications for a cathodic protection system.
Classification / Gas Industry > Gas Network Planning and Development
Available grade / Achieved
Guidance Information
1This unit standard is intended for, but is not limited to, workplace assessment. The range statements relate to enterprise specific equipment, procedures, and processes.
2The current version of the following documents must be complied with:
Health and Safety at Work Act 2015;
Resource Management Act 1991;
NZS 5258:2003 Gas distribution networks;
AS/NZS 4645.1:2008 Gas distribution networks – Network management;
AS/NZS 4645.2:2008 Gas distribution networks – Steel pipe systems;
AS/NZS 4645.3:2008 Gas distribution networks – Plastic pipe systems;
NZS 5259:2015Gas measurement.
3Any new, amended or replacement Acts, regulations, standards, codes of practice, guidelines, or authority requirements or conditions affecting this unit standard will take precedence for assessment purposes, pending review of this unit standard.
4References
Australian/New Zealand standards (AS/NZS) may be found at
New Zealand standards (NZS) may be found at
5Definition
Company procedures means the documented methods for performing work activities and include health and safety, environmental, and quality management requirements. They may refer to manuals, codes of practice, or policy statements
Outcomes and performance criteria
Outcome 1
Demonstrate knowledge of cathodic protection systems in a gas distribution network.
Performance criteria
1.1Principles of operation of cathodic protection systems are explained in terms of industry usage.
Rangerectifier impressed current, anode beds, galvanic anodes, test points.
1.2The relevance of cathodic protection systems to functional performance, and security requirements of gas networks is explained in terms of industry usage.
1.3Equipment used for cathodic protection systems is described in terms of function and industry usage.
Rangecopper sulphate half cell, multimeter, data logger, analogue to digital converter, cathodic protection system interruption device, direct current voltage gradient meter, pipe locater, flange isolation tester, sacrificial anodes, ground beds, transformers, rectifiers, insulation, cross bonding, Holiday detector.
Outcome 2
Produce design specifications for a cathodic protection system.
Performance criteria
2.1The need to design a cathodic protection system is identified to meet system requirements in accordance with company procedures.
2.2Parameters are acquired to establish current requirements for cathodic protection system in accordance with company procedures.
Rangepipe surface area, type of coating, soil conditions, other underground services.
2.3Current generation type is established for acquired parameters in accordance with company procedures.
Rangesacrificial anode, impressed current.
2.4Sacrificial anode requirements are established from soil resistivity, ground bed size and design and physical factors.
2.5Impressed current requirements are established from soil resistivity and desired life span.
2.6Completed design specifications for cathodic protection systems are produced in accordance with company procedures and NZS 5258.
Rangestatutory considerations, overall design requirements, construction considerations, commissioning and recommissioning, alterations to live mains and services, corrosion protection, system monitoring, maintenance and records.
2.7Design plans for cathodic protection systems are prepared and include environmental considerations in accordance with company procedures.
Rangeaesthetics, disposal, life time of system, manufacturability, compatibility with existing system, upgrade potential, other utilities, test point location.
2.8Logistical requirements, including timetables for deliverables, are prepared in accordance with company procedures.
2.9Produced design specifications for cathodic protection systems are in the agreed format and style and are completed by the agreed time in accordance with company procedures.
Rangelocations, layouts and routes, definitions, glossary of terms.
2.10Produced design specification is documented and includes current version number and date produced in accordance with company procedures.
2.11Produced design specification is filed and is available to authorised users in accordance with company procedures.
Rangeauthorised users – customers, manufacturing, management, technical experts.
2.12Produced design specifications for cathodic protection are distributed to authorised personnel promptly on completion of design, and an up-to-date register of specification holders is maintained in accordance with company procedures.
Planned review date / 31 December 2019Status information and last date for assessment for superseded versions
Process / Version / Date / Last Date for AssessmentRegistration / 1 / 25 September 1997 / N/A
Revision / 2 / 3 August 2000 / N/A
Revision / 3 / 10 October 2002 / N/A
Rollover and Revision / 4 / 20 November 2006 / N/A
Revision and Rollover / 5 / 17 August 2017 / N/A
Consent and Moderation Requirements (CMR) reference / 0014
This CMR can be accessed at
Comments on this unit standard
Please contact MITO New Zealand Incorporated you wish to suggest changes to the content of this unit standard.
MITO New Zealand IncorporatedSSB Code 101542 / New Zealand Qualifications Authority 2018