Canadian Underground Infrastructure Logo

Electronic water treatment reduces fouling and corrosion in pipelines

By Jan De Baat Doelman

Electronic water treatment reduces fouling and corrosion in pipelines

Increasing pressure loss in a pipeline is often caused by scale corrosion or product fouling of the internal surfaces. This condition slows transmission and distribution capacity, and can require more than just routine maintenance if it remains unaddressed. Interior corrosion, fouling and leakage in pipeline systems will adversely impact bottom-line operations. 

If you see corrosion and fouling on part of the pipeline the chances are it is occurring throughout the length of the pipes. If the corrosion is left untreated, it can weaken the pipe walls to the extent that the entire pipeline will need to be completely replaced. The ideal solution is to treat pipelines so that fouling and corrosion does not occur. Hard water is corrosive to metallic tubes and contributes to fouling and bacterial contamination that eats away at the piping surfaces. Leaks and damage, pitting and obstructive buildup all require frequent maintenance.

Scaling deposits are common in flowlines subject to changes of pressure or temperature. Regardless of how hard water effects are achieved, the outcome is the same. Scale formation results in reduced diameter or blocked pipes. Pipework scale reduces the available cross-section area, and fluids are affected by increased pipewall friction. A larger, more power-consuming pump will be required to maintain throughput volumes but this may allow only a temporary solution to the problem.

The formation of a thin uniform layer of scale or wax temporarily can reduce steel corrosivity, but eventually stagnant conditions develop under the deposit and electrochemical reactions will corrode the steel surfaces. The result can be fluid leaks and equipment failure, which are potentially very dangerous. Not only is plant and product integrity at risk but personnel health and safety may be compromised. Safety valves or emergency process sensors that are fouled may not operate in an emergency.

Electronic Water Treatment (EWT) is a non-invasive system utilizing a solenoid coil or coils wrapped around the pipework to be treated.

Electronic Water Conditioning

Electronic Water Treatment (EWT) is a non-invasive system utilizing a solenoid coil or coils wrapped around the pipework to be treated. A continuously variable frequency signal generator, within a specified range, supplies current to the coils. The pulse shaped current creates an induced electric field, concentric around the axis inside the pipe. As a consequence to this arrangement, any charged particle or ion moving within the field experiences a so-called Lorentz force generated by the interaction between charged particles and magnetic and electric fields.

The treatment influences the initial nucleation, resulting in crystals that do not “stick” together. Untreated water builds up matted structures that continuously grow. This treatment creates idiomorphic, scattered crystals, which do not form matted structures. They have a rotundas shape, which means that they have a larger volume in relation to a smaller surface. This feature makes them sensitive to water currents and they are easily flushed out of the pipeline. As no new scale layers are formed, the sheer force of the water flow will gradually remove existing layers of scale. The ability to adjust power, frequency and coil configurations of products like the Scalewatcher on site enables performance to be optimized with no downtime and no pipe replacement.