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API RP 1626-2010 (2012): Recommended Practice for Storing and Handling Ethanol and Gasoline-Ethanol Blends at Distribution Terminals and Service Stations
Technical Guide to Design, Construction, Operation, and Compliance for Ethanol-Gasoline Blend Facilities
Scope and Application
API Recommended Practice 1626, originally published in 2010 and reaffirmed in 2012, provides comprehensive guidance for the design, construction, operation, and maintenance of facilities that store and handle ethanol and gasoline-ethanol blends. The standard addresses both distribution terminals and service stations, covering ethanol contents ranging from E10 (10% ethanol) up to E85 (85% ethanol) and higher. It applies to new installations as well as the conversion of existing storage and handling systems for use with ethanol blends.
The scope includes bulk storage tanks, piping systems, loading/unloading areas, dispensing equipment, and ancillary safety systems. By consolidating industry knowledge and operational experience, API RP 1626-2010 (2012) serves as a key reference for engineers, facility operators, and regulatory compliance professionals working with ethanol-blended fuels.
Tip: API RP 1626 is complementary to other API and NFPA standards. When designing a new ethanol blend facility, cross‑reference API RP 1626 with NFPA 30, API RP 2003, and local fire codes to ensure a complete safety framework.
Key Technical Requirements
Material Compatibility
Ethanol and gasoline-ethanol blends can interact with common construction materials in ways that differ from conventional gasoline. API RP 1626-2010 (2012) emphasizes the need for compatibility assessments for every component in direct contact with the fuel. The table below summarizes typical material recommendations.
| Component | Recommended Materials | Comments |
|---|---|---|
| Storage Tank (Aboveground) | Carbon steel (with internal coating) or fiberglass-reinforced plastic (FRP) | Internal coating required for steel tanks to prevent corrosion from ethanol’s hygroscopic nature. |
| Storage Tank (Underground) | FRP or steel with corrosion protection and internal coating | Secondary containment and interstitial monitoring strongly recommended. |
| Piping | Stainless steel (304/316), FRP, or flexible metallic hose with ethanol‑rated liner | Avoid copper, zinc, or aluminum alloys that may react with ethanol. |
| Seals, Gaskets, O‑Rings | Fluoroelastomers (FKM), PTFE, or ethylene‑propylene (EPDM) | Nitrile (Buna‑N) may swell or degrade when exposed to high‑ethanol blends. |
| Pump Internals | Stainless steel, nickel‑alloy, or engineered polymers | Check manufacturer certification for ethanol blend service. |
Warning: Even trace amounts of ethanol can cause stress corrosion cracking in certain brass or aluminum fittings. Replace all non‑approved materials before introducing ethanol blends into an existing system.
Storage Tank Design and Protection
The recommended practice specifies minimum requirements for tank construction, venting, overfill prevention, and secondary containment. For aboveground storage tanks (ASTs), the standard calls for:
- Internal coating systems tested for ethanol exposure (e.g., epoxy or phenolic linings).
- Vent systems equipped with flame arresters and pressure/vacuum relief capable of handling ethanol’s higher vapor pressure.
- Overfill prevention devices (level alarms, automatic shutdown) that meet API RP 2350.
For underground storage tanks (USTs), API RP 1626-2010 (2012) recommends:
- Spill containment sumps in fill and dispenser areas.
- Interstitial monitoring where double‑wall tanks are used.
- Upgraded corrosion protection systems to account for the increased conductivity of ethanol‑blended fuels.
Fire Protection and Operations
Ethanol fires are distinct from hydrocarbon fires because ethanol is water‑miscible and burns with a nearly invisible flame. The standard advises that fire‑protection systems be designed accordingly, using alcohol‑resistant foam concentrates (AR‑AFFF) for spill fires. Operational requirements include:
- Dedicated water supply for foam generation.
- Personnel training on ethanol‑specific fire hazards.
- Procedures for receiving, storing, and dispensing that minimize vapor release and electrostatic ignition.
Best Practice: Facilities that convert from gasoline to ethanol blends often see reduced vapor emissions during loading because ethanol’s vapor pressure is lower. However, tanks must still be properly inerted and monitored for oxygen during switchover.
Implementation and Operational Considerations
Successful adoption of API RP 1626-2010 (2012) requires careful planning for both new facilities and retrofit projects. The recommended practice dedicates substantial sections to:
Retrofitting Existing Equipment
When converting a gasoline terminal or service station to handle ethanol blends, every component from tank to dispenser must be evaluated. API RP 1626 provides a structured approach:
- Inventory all wetted materials.
- Remove or replace incompatible metals, elastomers, and plastics.
- Flush and clean the system to remove water, sediment, and old fuel residue.
- Test the system with the target ethanol blend before full‑scale operation.
Quality Control and Water Detection
Ethanol’s affinity for water makes water monitoring a critical operational task. The standard suggests:
- Installing water‑sensing probes in tank sumps.
- Performing frequent tank bottom sampling for water content.
- Maintaining fuel dryers or filtration systems where humid climates require them.
Inspection and Maintenance
API RP 1626-2010 (2012) references industry‑standard inspection intervals (API 653 for ASTs, API 570 for piping) and adds ethanol‑specific checks, such as verifying the condition of internal coatings and examining seals in loading arms and hoses. Documentation of inspections and repairs is essential for regulatory compliance and insurance requirements.
Danger: Never operate a facility that handles ethanol blends without confirming that all fire‑protection systems are rated for alcohol fires. Using standard hydrocarbon foam on an ethanol fire can cause the fire to spread uncontrollably.
Compliance and Reaffirmation Notes
API RP 1626-2010 (2012) was reaffirmed in 2012 following review by the API Downstream Segment committee. Reaffirmation indicates that the technical content remains current and no revisions were necessary at that time. However, users should verify with the latest API publications because newer editions may have been published after 2012. The standard is not legally binding in itself, but it is widely referenced by regulators (e.g., U.S. EPA for UST compliance, OSHA process safety management) and incorporated into local fire codes.
Key compliance points for operators:
- Adherence to the recommended practice may qualify as evidence of due diligence during regulatory inspections or audits.
- Insurance carriers often require compliance with applicable API RPs for coverage.
- State and local authorities may mandate specific provisions of API RP 1626 through permit conditions.
The reaffirmed status of the 2010 edition means that facilities designed during the 2010–2012 period are aligned with industry expectations at that time. For newer or retrofitted installations, it is prudent to compare the 2010/2012 recommendations with any subsequent updates or addenda issued by API.
Note: Always check API.org for the most current version of RP 1626. As of 2026, the 2010 edition is still listed as active, but periodic confirmations are recommended.
Frequently Asked Questions
Q: What is the primary scope of API RP 1626-2010 (2012)?
A: The standard covers design, construction, operation, and maintenance of storage and handling systems for ethanol and gasoline-ethanol blends (E10 to E85) at distribution terminals and service stations. It applies to both new facilities and retrofits of existing ones.
A: The standard covers design, construction, operation, and maintenance of storage and handling systems for ethanol and gasoline-ethanol blends (E10 to E85) at distribution terminals and service stations. It applies to both new facilities and retrofits of existing ones.
Q: Are storage tank materials specifically addressed?
A: Yes. The recommended practice provides detailed guidance on materials for tanks, piping, seals, and ancillary equipment. It strongly recommends carbon steel tanks with internal coatings or FRP tanks, and stainless steel or FRP piping. Incompatible materials such as copper, galvanized steel, and nitrile rubber must be avoided.
A: Yes. The recommended practice provides detailed guidance on materials for tanks, piping, seals, and ancillary equipment. It strongly recommends carbon steel tanks with internal coatings or FRP tanks, and stainless steel or FRP piping. Incompatible materials such as copper, galvanized steel, and nitrile rubber must be avoided.
Q: Does the 2012 reaffirmation change any technical requirements?
A: No. Reaffirmation means the committee concluded that the existing 2010 edition still represents sound engineering practice. No substantive changes were made, but users are responsible for checking whether subsequent editions or addenda have been released since 2012.
A: No. Reaffirmation means the committee concluded that the existing 2010 edition still represents sound engineering practice. No substantive changes were made, but users are responsible for checking whether subsequent editions or addenda have been released since 2012.
Q: What is the most critical operational difference between handling conventional gasoline and ethanol blends?
A: Ethanol’s hygroscopicity and conductivity demand extra attention to water monitoring and corrosion protection. Additionally, fire protection systems must be specifically designed for water‑miscible fuel fires, typically using alcohol‑resistant foam.
A: Ethanol’s hygroscopicity and conductivity demand extra attention to water monitoring and corrosion protection. Additionally, fire protection systems must be specifically designed for water‑miscible fuel fires, typically using alcohol‑resistant foam.
Article prepared for technical reference purposes. The information herein does not replace the original API RP 1626-2010 (2012) document. Always refer to the latest official API publication for full requirements and updates. — 2026