Our services
Diagnostics - DCVG
Outer inspection of burried oil, gas and water lines by means of DCVG method (Direct Current Voltage Gradient Survey) to precisely locate faults (defects) on a burried line in conjuction with GPS measurements, where such faults and other features of interest get precise (submeter to centimeter accuracy according to customer’s needs) global geocentric GPS coordinates and – hence – they can be staked out (re-located) by means of GPS at any time later for further inspection and/or repair works.
The DCVG technique is the most accurate technique available to industry in order to locate the faults in the protective coating on buried pipelines. Coating faults as small as a fingernail can be located to within a few centimetres on pipelines buried 1 to 2 metres deep. The technique is very versatile and can be used in complex pipeline networks, in city streets, across rivers and swamps, under overhead power lines and in areas subject to DC Traction interference.
Within the DCVG method the following tasks are performed:
- Searching and localization of epicentre of faults;
- Evaluation of faults with respect to their electric values;
- Measurements of directions of current in the epicenter of faults;
- Measurements of potential;
- Measurements of specific resistivity of soil in places of localized faults;
- Measurements for determination of the deep of the line in the land;
- Processing of all measured values in electronic and written form including a detail analysis regarding to their impact on existing status and effectivness of anti-corrosion protection of lines.
Within corrosion measurements the following tasks are conducted:
- Measurements of apparent specific resistivity of soil;
- Measurements of size and most dominant directions of false currents, current fields, interference currents along with proposal for their elimination, alternate ground currents along with proposal for their elimination;
- Measurements of potentials Eon, Eoff, En;
- Measurements of quality about realisation of isolation of constructions and their overstress protection;
- Determination of effectiveness of operation of existing devices for anti-corrosion protection (checking of their current setups, effectivity, critical places, etc.);
- Special measurements (for example – to determine the quality of isolation layers, their lifetime);
- Set-up of temporary cathodic protection stations;
- Creation of corrosion maps;
- Measurements for elimination of biological influences;
- Proposals for application of protection and isolation layers;
- Feasibility studies.
Projection (Designing)
Each pre-project preparation includes:
- Conception proposal;
- Preparation, projection and consultancy;
- Corrosion reconnaissance in accordance with european norms (EN) 13509, 12696, 12954;
- Developing of a study of corrosion influences;
- Developing of documentations of building design regarding corrosion and anti-corrosion protection usually based on a feasibility study.
