CASE STUDIES

24km long, 2.4m to 1.8m Diameter Concrete Coated Steel Pipeline

This pipeline emanates from the Faure Water Treatments works near Somerset West and terminates in Philippi. A unique set of environmental factors necessitated the installation of a cathodic protection system to this pipeline.

DC stray current from railway activity, chlorides and a relatively high water table throughout the length of the pipeline route contributed to the corrosive forces arrayed against this pipeline. Extensive testing, investigation and field surveys led to the installation of a cathodic protection system during the period August 2000 and January 2003.

Commissioning reporting and field results are due to be presented to the end user shortly.

Durban Municipality Corrosion System Project Management

The eThekwini Water Services department appointed Paradigm Projects (Pty) Ltd during 2001 to take over management of approximately 45 cathodic protection systems situated throughout the greater Durban municipal area.

The assignment comprises comprehensive overview of all existing protection philosophies, implementation of investigations, appointment of consultants, preparation of project briefs, budget estimation and the provision expert opinion.

At present the sphere of influence of this assignment includes approximately 1200km of pipeline network in excess of 300mm diameter.

Cathodic Protection System Assessment for Fire Main Pipeline Network for Monsanto, Camacari, Bahia, Brazil

Paradigm Projects (Pty) Ltd were appointed by Matcor Inc, Philadelphia, USA (www.matcor.com) to carry out commissioning and field exercises to the newly

commissioned Monsanto Roundup facility in northern Brazil (www.mosanto/locations/brazil).

The field surveys included commissioning activities and a close interval potential survey over the full length of fire main network. Additional activities surrounded the integration of field instrumentation via transducers to the plant process control network.

Cathodic Protection Monitoring and Maintenance for the Department of Water Affairs and Forestry

Paradigm Projects (Pty) Ltd have been appointed on a regular basis to execute routine maintenance and monitoring activities on a variety of pipelines for the Department of Water Affairs and Forestry (www.dwaf.gov.za) throughout South Africa.

One of the greatest challenges is the Vaal-Gama-Gara water scheme that extends over some 300km in arid conditions running parallel to the Sishen - Saldana DC electrified railway line. Stray current activity on this pipeline is unique and poses several maintenance challenges.

Other pipeline networks are distributed across the Mpumalanga province where critical pipelines supply water to key Eskom power stations.

Heat Exchanger Corrosion Assessment at Hillside Aluminium - BHP Billiton Group

Paradigm Projects (Pty) Ltd carried out a detailed corrosion assessment and rehabilitation proposal for the heat exchangers cooling the critically important main transformer rectifier units providing the smelter potline with DC power.

The investigation and proposal included assessment of the corrosion environment, risk of failure, mechanical conditions and outlining a suitable corrosion prevention system.

(www.bhpbilliton.com/aluminium)

Cathodic Protection of a Low Pressure Gas Bullet - Afrox Limited, Tsogo Sun Casino

Paradigm Projects (Pty) Ltd offered a full turnkey solution for this project carrying out all field surveys, site installations, commissioning and handover to the client.

The LPG bullet is situated below ground at the new Tsogo Sun Casino and provides the primary energy source for cooking. The concern for the client was the corrosive soil environment and the fact that the LPG bullet was to be buried for aesthetic purposes.

A sacrificial magnesium anode cathodic protection was installed to provide corrosion protection to this critical installation.