The EPDM rubber expansion joint in the fuel oil transfer line lasted four months before swelling to twice its original diameter, losing flexibility and eventually tearing from internal pressure. The replacement neoprene expansion joint endured six months before hardening and cracking due to aromatic hydrocarbon exposure.
The third installation used a viton expansion joint and has operated successfully for five years under the same conditions with no visible degradation. Identical operating conditions produced dramatically different outcomes based on elastomer chemistry. Chemical resistance determines whether expansion joints last months or decades in petrochemical and chemical processing environments. For facilities handling petroleum products and aggressive chemicals, viton expansion joint construction by Zepco LLC offers reliable long-term performance.
Chemical Exposure Performance
Elastomers face a series of chemical challenges in industrial settings. Each chemical acts as a test eliminating weaker materials while viton endures. This discussion presents chemical exposure scenarios and explains how viton expansion joints maintain performance while other materials show limitations.
Petroleum Products and Hydrocarbon Fuels
Petroleum products such as gasoline, diesel fuel, jet fuel, fuel oil and crude oil contain aromatic hydrocarbons including benzene, toluene and xylene. These compounds interact with elastomers causing swelling and loss of mechanical integrity.
EPDM rubber expansion joints absorb aromatic hydrocarbons quickly, increasing in volume by 50 to 200 percent within days or weeks. Flexibility diminishes, tensile strength decreases and surfaces become brittle. Neoprene expansion joints show moderate resistance but still swell 20 to 60 percent and develop hardening or cracking. Natural rubber deteriorates when exposed to petroleum products.
Viton expansion joints resist hydrocarbon penetration due to fluoroelastomer chemistry. The carbon-fluorine bonds provide durability that preserves flexibility, tensile strength and dimensional stability. Zepco LLC’s viton expansion joints perform reliably in refinery pipelines, fuel terminals and offshore transfer systems where continuous hydrocarbon contact occurs.
Acids and Oxidizing Chemicals
Mineral acids such as sulfuric, hydrochloric, nitric and phosphoric interact with most rubber compounds, causing hardening, embrittlement and surface cracking. Standard expansion joints experience progressive weakening that can result in failure over time.
Viton resists acid attack because the chemical stability of carbon-fluorine bonds prevents degradation. Zepco LLC’s viton expansion joints withstand concentrated sulfuric acid, hydrochloric acid, dilute and moderate nitric acid, and organic acids such as acetic, formic and citric acids. Oxidizing agents including hydrogen peroxide, chlorine and hypochlorites also do not compromise the integrity of viton materials, making them suitable for chemical bleaching, water treatment and specialty chemical processes.
Solvents and Aromatic Compounds
Industrial solvents, ketones and aromatic compounds affect standard rubber expansion joints by causing swelling and weakening. Chlorinated solvents such as methylene chloride and trichloroethylene can double the volume of EPDM and neoprene. Ketones including acetone, MEK and MIBK reduce strength, and aromatic compounds penetrate molecular structures causing degradation.
Viton expansion joints resist most industrial solvents, preserving performance under chemical exposure where other elastomers experience frequent replacement. For specific polar solvents including ketones and esters, PTFE-lined or specialty constructions are available to ensure complete chemical resistance.
High-Temperature Chemical Service
Chemical attack accelerates as temperature increases. Reaction rates double with each rise of 10 to 20 degrees Fahrenheit. EPDM may fail within weeks at elevated temperatures even when rated for 300 degrees Fahrenheit in air, and neoprene loses moderate hydrocarbon resistance above 150 degrees Fahrenheit.
Viton expansion joints maintain continuous performance at 400 degrees Fahrenheit while retaining chemical resistance. Applications include hot fuel oil systems in power plants, high-temperature acid processes, heated solvent vapor recovery and any process combining chemicals and elevated temperature. This combination provides long-term reliability and supports consistent operational performance.
Material Selection Considerations
EPDM performs well in hot water and steam applications and provides a cost-effective option for non-chemical service. Neoprene is suitable for outdoor installations due to weather and ozone resistance. Viton expansion joints should be specified when petroleum products, fuels or oils contact the surfaces, acids, solvents or aggressive chemicals are present, elevated temperature coincides with chemical exposure or long service life of ten years or more is desired. Standard elastomers remain suitable for water, steam and air service where chemical exposure is minimal.
Economic Justification
Initial cost comparison shows EPDM expansion joints ranging from $1,200 to $2,500, neoprene from $1,500 to $3,200 and viton from $3,500 to $7,500. Lifecycle analysis over ten years demonstrates that chemical service applications require multiple replacements for standard elastomers, resulting in cumulative costs of $10,000 to $16,000 including installation and downtime. Viton expansion joints require one replacement or none, keeping total costs between $3,500 and $7,500. Non-chemical service applications show a smaller difference in cost but maintain viton’s reliability.
Viton expansion joints from Zepco LLC reduce maintenance frequency, downtime and overall expenses, providing a cost-effective solution for facilities handling petroleum products, acids, solvents and other aggressive chemicals.
Conclusion
Viton expansion joint construction from Zepco LLC provides exceptional chemical and hydrocarbon resistance, supporting long service life and reliable performance in refining, chemical processing, fuel handling and acid service operations. Matching elastomer chemistry to the chemical environment ensures operational stability, reduces maintenance needs and protects investment over time. Facilities benefit from selecting the appropriate elastomer to maintain continuous performance and maximize long-term value. Zepco LLC offers comprehensive solutions across elastomer specifications to meet the needs of diverse industrial applications.
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