When Tank Cleaning Becomes Necessary
Even with the best preventive measures in place, fluid storage tanks eventually accumulate contamination that requires active remediation. Sediment settles at the bottom, forming a sludge layer that can be resuspended during high-flow dispensing operations. Corrosion products build up on interior surfaces. Microbial colonies establish themselves in water layers and spread to tank walls and baffles. Varnish and oxidation deposits coat internal surfaces, gradually releasing contaminants into the stored fluid. When routine fluid testing reveals contamination levels trending upward despite normal filtration maintenance, or when visual inspection through manways and access ports shows visible deposits, it is time for a tank cleaning intervention.
Tank Cleaning Methods
Manual tank cleaning involves draining the tank, entering the confined space with appropriate safety precautions, and physically removing sludge, deposits, and contamination from interior surfaces. This method provides the most thorough cleaning and allows direct inspection and repair of internal surfaces, but it is labor-intensive, requires the tank to be completely taken out of service, and generates waste material that must be disposed of properly. Manual cleaning is typically reserved for heavily contaminated tanks or situations where internal repairs are needed.
Automated tank cleaning uses specialized equipment to clean tank interiors without requiring human entry. Rotating spray heads mounted through access openings deliver high-pressure cleaning fluid to all internal surfaces, dislodging deposits and flushing contamination to the tank bottom for removal. This method is faster, safer, and often more economical than manual cleaning for tanks that do not require internal repairs. It is particularly suited to large tanks where manual cleaning would be prohibitively time-consuming.
Filtration-based cleaning, sometimes called tank polishing, uses a high-capacity filtration system connected to the tank to circulate and clean the fluid in place. The filtration system processes the entire tank volume multiple times, progressively removing particles, water, and degradation products. This approach has the advantage of cleaning both the fluid and the tank interior simultaneously without draining the tank or taking it out of service. It is most effective for maintaining tanks that are not severely contaminated and as a follow-up treatment after mechanical cleaning.
Developing a Tank Cleaning Schedule
The optimal tank cleaning frequency depends on the fluid type, tank construction, environmental conditions, and the contamination tolerance of the equipment being served. Fuel tanks in humid environments may require cleaning every two to five years. Lubricant tanks in controlled environments may go much longer between cleanings. The most reliable approach is to base cleaning decisions on fluid test data—when contamination levels approach your limits despite normal filtration maintenance, it is time to clean.
Post-Cleaning Filtration
After any tank cleaning operation, the stored fluid requires filtration to remove any contamination mobilized by the cleaning process. Even filtration-based cleaning may temporarily increase contamination levels as settled deposits are disturbed. Running the recirculation filtration system at maximum capacity after cleaning ensures that the fluid is brought back to target cleanliness as quickly as possible. Clean Fluid Solutions provides tank cleaning services and filtration systems that restore your storage tanks to optimal condition and maintain them for extended service.
