Everything to Know About SSPC-SP 1 Solvent Cleaning for Storage Tanks

Storage tanks play a crucial role in various industries, storing liquids ranging from water and chemicals to petroleum. Ensuring the longevity and integrity of these tanks requires adherence to strict cleaning standards by tank owners and API inspection services providers. One such standard, SSPC-SP 1, focuses on solvent cleaning as a fundamental step in the surface preparation process.

Let’s delve into everything you need to know about SSPC-SP 1 solvent cleaning for storage tanks.

Understanding SSPC-SP 1

SSPC-SP 1, or Solvent Cleaning, is a surface preparation standard set by the Society for Protective Coatings (SSPC). It provides guidelines for the removal of contaminants, such as oil, grease, and other soluble matter, from the surfaces of steel structures, including storage tanks.

Importance of Solvent Cleaning

Contaminant Removal: Storage tank surfaces must be free from contaminants to ensure proper adhesion of protective coatings. Solvent cleaning is particularly effective in removing oils, greases, and other organic substances that might compromise coating performance.

Enhancing Coating Performance: Adequate surface preparation, including solvent cleaning, is essential for the longevity and effectiveness of protective coatings. A clean surface ensures that coatings adhere properly, preventing premature failure and corrosion.

Steps in SSPC-SP 1 Solvent Cleaning

Material Inspection: Before initiating solvent cleaning, inspect the storage tank surface for visible contaminants. Common contaminants include oil, grease, dust, and other soluble materials.

Selecting the Right Solvent: The choice of solvent depends on the type of contaminants present. Solvents like mineral spirits, acetone, or denatured alcohol may be used. It’s crucial to follow safety guidelines and regulations when handling solvents.

Application Methods: Solvent cleaning can be accomplished through various methods, including wiping, brushing, or spraying. The goal is to apply the solvent thoroughly to dissolve and remove contaminants.

Surface Drying: After applying the solvent, the surface is allowed to dry completely before proceeding with additional surface preparation or coating application. Proper drying ensures that the solvent has effectively removed contaminants.

Safety Considerations:

Protective Measures: When conducting solvent cleaning, API 653 tank inspection services professionals must use personal protective equipment (PPE) such as gloves, goggles, and respiratory protection, depending on the solvent used. Adequate ventilation in the work area is essential.

Environmental Impact: Consideration is given to the environmental impact of solvents used. Adhering to regulations regarding solvent disposal is crucial to prevent environmental harm.

Challenges and Best Practices

Effectiveness on Different Contaminants: While highly effective against oils and greases, solvent cleaning may have limitations with certain contaminants. It’s essential to assess the specific needs of the storage tank and choose an appropriate cleaning method.

Integration with Overall Surface Preparation: Solvent cleaning is often one step in a multi-step surface preparation process. Integration with other methods, such as abrasive blasting, is common for achieving comprehensive surface cleanliness.

Compliance and Quality Assurance

Inspection and Verification: Regular inspections ensure that solvent cleaning is performed according to SSPC-SP 1 standards. Quality assurance measures, including documentation and testing, help confirm the effectiveness of the cleaning process.


SSPC-SP 1 Solvent Cleaning stands as a foundational element in the surface preparation journey for storage tanks. Adhering to this standard ensures that contaminants are effectively removed, setting the stage for the application of protective coatings. By understanding the importance, steps, safety considerations, and best practices associated with SSPC-SP 1, industries can maintain the structural integrity and longevity of their storage tanks, safeguarding valuable assets and minimizing the risk of corrosion.…

Frequently Asked Questions regarding STI inspections and SP001 Standards

Any industry dealing with Aboveground Storage Tanks must stay in compliance with the inspection standards laid down by the U.S Environment Protection Agency. The EPA is responsible for creating rules for Spill Prevention Control and Countermeasure or SPCC. Further, the Steel Tank Institute released the first edition of the STI inspections standards that guide the aboveground tank owners on how to comply with the EPA mandates. Since its first release in the year 2000, the standards are constantly updated.

In this blog, we answered a few frequently asked questions regarding the updated STI testing standards.

  • Why is there a need for internal tank inspection of a shop-fabricated tank if the tank’s inside is not easily accessible?

According to the STI SP001, there is no need to enter into the tank that has the capacity of 30,000 gallons or less. While inspecting such tanks, internal inspections are not mandatory. Other alternative tank testing methods can be used to look for defects or leakage. Similarly, tanks that are larger than 30,000 gallons have dedicated entryway for inspectors to enter into the tank for inspection.

  • Is any requirement for the inspection of fiberglass or plastic tanks?

The STI inspection standard revolves around the inspection of field-erected tanks, and stainless steel shop fabricated tanks and welded tanks. The STI standards also have separate provisions for the assessment of portable or small-sized containers. However, the standards do not mention the inspection of fiberglass tanks or shop-fabricate d plastic tanks.

  • What are the provisions for UT reading included in the latest edition of the STI inspection standards?

Earlier, there were no provisions for a risk-based approach in STI inspection standards. However, the standard made it mandatory for the inspectors to conduct UT testing on all the tanks. While conducting tests on tanks with specific capacities, one has to run thousands of readings.

In the 3rd and 4th editions of the revised STI inspection standards, much emphasis on a risk-based inspection approach has been given. The standard has mentioned the number of UT readings taken per square foot of tank surface area in the newer edition. However, the standard does not mention the areas for reading.

According to the STI standards, the certified inspector should use his judgment to identify the area where the corrosion is most likely to be present.

  • What are the STI inspection standards for insulated tanks?

It is challenging to detect corrosion present underneath the insulated tank. Undetected moisture or water inside the tank can leak to corrosion or contamination of the stored fuel.

According to the STI inspection standards, one must remove the insulation from the area where moisture or mold is most likely to accumulate. Once the insulation is removed, the inspectors can conduct the further examination.

  • Who can conduct an STI inspection?

The STI inspection standards clearly describe the two basic types of AST inspections. Monthly inspections can be performed by a qualified inspector hired by the tank owner. On the other hand, certified tank inspectors should perform external and internal checks with appropriate training.…