Substation Corrosion Maintenance – High Ratio Calcium Sulfonate Alkyd (HRCSA) Anti-Corrosion Sealant Technology

Weathered substation equipment and supporting structures are effectively treated with High Ratio Calcium Sulfonate Alkyd (HRCSA), a high performance anti-corrosion sealant system which is available through Afrisun Coating Enterprises (Pty) Ltd. It is important for any Electrical Substation Manager to be proactive in monitoring the presence of corrosion damage to equipment. Coating failure is most often seen where crevices are formed.

Dismantling and removal of corroding substation equipment in order to repair and re-coat equipment is the conventional process but this process requires highly skilled workers, a budget to pay for this expensive process and extended down-time of substations. This process can be avoided when using HRCSA anti-corrosion encapsulating sealants. The HRCSA innovative method of in-sito equipment rehabilitation will drastically reduce down-time, costs and risks involved when substations are being treated to stop corrosion. The HRCSA sealant system is now a Specified method of transformer protection for the City of Cape Town.

Substation coatings do deteriorate over time, but accelerated deterioration takes place in micro environments where corrosive contaminants accumulate. In crevices however, when passive barrier coatings, such as Epoxies or Urethanes are applied, the failures seen are caused by a few factors. In crevices one finds that a lot of studies have pointed to a phenomenon called Differential Aeration Corrosion (DAC). DAC causes the micro-environment to become acidic and this causes passive barrier coatings to fail prematurely. DAC is caused by the decrease of oxygen in the presence of moisture inside crevices, causing a lowering of the pH (more acidic) in micro-environments which accelerates corrosion. Coating failure inside these micro-environments then causes entrapment of corrosive material such as Chlorides (sea spray) and pollutants.

HRCSA is an active sealant that properly wets-out micro-environments and surfaces being treated and is formulated to over coat a variety of coatings that are adherent onto structures especially Hot Dip Galvanizing (HDG). HDG is not affected by DAC as the HRCSA lifts the pH to 10.1 which passivates the HDG coated surfaces.

In the case of substation coatings, when coatings start failing in said environments, it becomes essential for Substation Managers to address these issues but because of the complex method of dismantling and removal of components from substations and to either replace or rehabilitate effected parts, leaves the Substation Manager with the attractive option of having the adherent coatings sealed off with HRCSA active sealants. This simple process alleviates the situation of prolonged downtime and thus a reduction in disruptive power outages.

Erosion of passive barrier coatings along edges of substation equipment causes a breech in the passive barrier and once this occurs, corrosion under creep will occur and result in metal loss. This then leads to the formation of pack rust, the most severe form of corrosion. HRCSA effectively seals off eroded passive barriers.

A galvanic cell formation, is formed when multi-metals are in direct contact with each other in the presence of moisture. A galvanic cell can be effectively prevented with active sealant anti-corrosion systems, such as Cathodic Protection (CP) or HRCSA is applied.

Both the HRCSA Clear Penetrant Sealant and Top Coat lifts the pH > 10.1 where the product has been applied over HDG, thereby actively mitigating corrosion. This high alkaline environment actively stops any further corrosion damage to substation equipment such as transformers and supporting structures. The HRCSA also makes the surface hydrophobic, preventing moisture and oxygen ingress into the crevices.

Afrisun Coating Enterprises (Pty) Ltd can be consulted on methods of remedial applications to treat crevices as well as entire surfaces of Substation equipment and supporting structures.

Substations

Substation Corrosion Maintenance – High Ratio Calcium Sulfonate Alkyd (HRCSA) Anti-Corrosion Sealant Technology

Weathered substation equipment and supporting structures are effectively treated with High Ratio Calcium Sulfonate Alkyd (HRCSA), a high performance anti-corrosion sealant system which is available through Afrisun Coating Enterprises (Pty) Ltd. It is important for any Electrical Substation Manager to be proactive in monitoring the presence of corrosion damage to equipment. Coating failure is most often seen where crevices are formed.

Dismantling and removal of corroding substation equipment in order to repair and re-coat equipment is the conventional process but this process requires highly skilled workers, a budget to pay for this expensive process and extended down-time of substations. This process can be avoided when using HRCSA anti-corrosion encapsulating sealants. The HRCSA innovative method of in-sito equipment rehabilitation will drastically reduce down-time, costs and risks involved when substations are being treated to stop corrosion. The HRCSA sealant system is now a Specified method of transformer protection for the City of Cape Town.

Substation coatings do deteriorate over time, but accelerated deterioration takes place in micro environments where corrosive contaminants accumulate. In crevices however, when passive barrier coatings, such as Epoxies or Urethanes are applied, the failures seen are caused by a few factors. In crevices one finds that a lot of studies have pointed to a phenomenon called Differential Aeration Corrosion (DAC). DAC causes the micro-environment to become acidic and this causes passive barrier coatings to fail prematurely. DAC is caused by the decrease of oxygen in the presence of moisture inside crevices, causing a lowering of the pH (more acidic) in micro-environments which accelerates corrosion. Coating failure inside these micro-environments then causes entrapment of corrosive material such as Chlorides (sea spray) and pollutants.

HRCSA is an active sealant that properly wets-out micro-environments and surfaces being treated and is formulated to over coat a variety of coatings that are adherent onto structures especially Hot Dip Galvanizing (HDG). HDG is not affected by DAC as the HRCSA lifts the pH to 10.1 which passivates the HDG coated surfaces.

In the case of substation coatings, when coatings start failing in said environments, it becomes essential for Substation Managers to address these issues but because of the complex method of dismantling and removal of components from substations and to either replace or rehabilitate effected parts, leaves the Substation Manager with the attractive option of having the adherent coatings sealed off with HRCSA active sealants. This simple process alleviates the situation of prolonged downtime and thus a reduction in disruptive power outages.

Erosion of passive barrier coatings along edges of substation equipment causes a breech in the passive barrier and once this occurs, corrosion under creep will occur and result in metal loss. This then leads to the formation of pack rust, the most severe form of corrosion. HRCSA effectively seals off eroded passive barriers.

A galvanic cell formation, is formed when multi-metals are in direct contact with each other in the presence of moisture. A galvanic cell can be effectively prevented with active sealant anti-corrosion systems, such as Cathodic Protection (CP) or HRCSA is applied.

Both the HRCSA Clear Penetrant Sealant and Top Coat lifts the pH > 10.1 where the product has been applied over HDG, thereby actively mitigating corrosion. This high alkaline environment actively stops any further corrosion damage to substation equipment such as transformers and supporting structures. The HRCSA also makes the surface hydrophobic, preventing moisture and oxygen ingress into the crevices.

Afrisun Coating Enterprises (Pty) Ltd can be consulted on methods of remedial applications to treat crevices as well as entire surfaces of Substation equipment and supporting structures.