Skip to content

Case Study

ChemLINE® 784Sodium Bisulfite

Seven-Year Rail Tank Car Inspection Shows Only 0.044% Coating Loss with ChemLINE®

When Southern Ionics Incorporated sought a more durable alternative to conventional rubber linings, ChemLINE® 784/32 delivered. After seven years of transporting sodium bisulfite, inspections of two rail tank cars revealed just 0.044% coating loss, demonstrating exceptional chemical resistance and long-term durability.

7 years
Years in service
0.044%
Coating loss to date
12+
Years of performance expected in this service

The Problem

Rising Maintenance Costs. Repeated Repairs.

Southern Ionics Incorporated was facing mounting maintenance expenses with its conventional rubber-lined rail tank cars. Lining replacements could cost as much as $40,000 per car, while individual shop visits for repairs added another $5,000–$7,000. With maintenance costs continuing to rise, Southern Ionics needed a more durable, cost-effective solution that could reduce recurring repairs and provide dependable long-term protection.


 

 

The Service

Long-Term Protection in Aggressive Sodium Bisulfite Service

Sodium bisulfite is an acidic, corrosive chemical used in industrial applications, making reliable tank lining protection essential for safe transportation. Following successful applications in its trailer fleet, Southern Ionics selected ChemLINE® 784/32 for two rail tank cars transporting sodium bisulfite. Applied in 2015, the two-coat polymer lining system was engineered to provide superior chemical resistance, protect against corrosion, and withstand the demands of prolonged chemical exposure.

Results

Seven Years in Service. Just 0.044% Coating Loss.

Following seven years of continuous sodium bisulfite service, an inspection conducted in March 2022 revealed just 0.044% coating loss based on dry film thickness measurements. The tank barrel remained in excellent condition, with only two localized areas of mechanical damage requiring minor repairs. The findings demonstrated ChemLINE®'s exceptional durability, coating integrity, and long-term corrosion protection in demanding rail transportation service.

  • 0.044% coating loss after seven years
  • Exceptional Coating Integrity with the tank barrel remaining in excellent condition.
  • Minimal Repairs Required with only two localized areas of mechanical damage.
  • 12+ Years Projected Service Life based on APC's technical assessment.

Conclusion

Proven Performance That Changed an Entire Fleet's Direction

The seven-year inspection results reinforced Southern Ionics' confidence in ChemLINE® as a long-term alternative to traditional rubber linings. With APC projecting 12+ years of service life under proper operating and maintenance conditions, Southern Ionics made the decision to transition its rail tank car fleet to ChemLINE®.

The results demonstrate how proven coating technology can help operators reduce maintenance demands, extend lining service life, and improve the long-term economics of chemical transportation.