Hastelloy C22 / C276 Flanges

Hastelloy C22 and C276 flanges are manufactured from high-performance nickel-chromium-molybdenum alloys that are specifically designed to resist some of the most aggressive chemical environments known to modern industry. These flanges are composed primarily of nickel, with varying amounts of chromium, molybdenum, cobalt, and iron. C22 contains higher levels of chromium, providing improved resistance to oxidizing agents, while C276 offers excellent resistance to both oxidizing and reducing conditions, even under extreme thermal and pressure cycles. The microstructure of these alloys enables the formation of a stable passive film that provides robust protection against localized corrosion forms such as pitting, crevice corrosion, and stress corrosion cracking.

Both C22 and C276 flanges are engineered to maintain mechanical integrity across a wide temperature range and are suitable for both cryogenic and elevated temperature environments. They demonstrate exceptional weldability and do not require post-weld heat treatment, which simplifies fabrication and installation. Typically, these flanges are available in configurations including slip-on, weld neck, blind, socket weld, threaded, and lap joint types, manufactured in compliance with ASTM B564 and ASME B16.5 standards. The mechanical properties of Hastelloy C22 and C276 include tensile strengths in the range of 690–760 MPa and yield strengths between 283–355 MPa, depending on the specific grade and processing method. These attributes ensure reliable performance in high-stress applications, particularly where exposure to aggressive chemical media is routine.

The unique metallurgical composition of these flanges makes them ideal for environments containing hydrochloric, sulfuric, nitric, and phosphoric acids, as well as other harsh organic and inorganic compounds. Their resistance to oxidizing aqueous media and wet chlorine environments makes them superior to many standard stainless steel and other nickel alloys. Hastelloy C22 and C276 also exhibit low thermal expansion and good thermal conductivity, which helps maintain dimensional stability under fluctuating temperatures. Their non-magnetic and spark-resistant characteristics further enhance their suitability for specialized industrial applications requiring high safety standards and material purity.

Applications

Hastelloy C22 and C276 flanges are widely used in applications that demand exceptional corrosion resistance and mechanical reliability in chemically aggressive conditions. In chemical processing industries, these flanges are integral to reactor vessels, heat exchangers, pressure vessels, and pipelines handling highly corrosive fluids. Their ability to withstand mixed acid streams and environments containing chlorides and oxidizers makes them a preferred choice in the production of fertilizers, dyes, acetic acid, and inorganic salts. These flanges also play a critical role in the handling and transport of waste acids, where failure due to corrosion could pose significant operational and environmental risks.

In pharmaceutical and food processing plants, where product purity and material hygiene are critical, Hastelloy flanges are used in piping systems that handle cleaning agents, sterilizing chemicals, and high-temperature fluids. Their smooth surface finish and resistance to contamination ensure compliance with stringent regulatory standards. Similarly, in pulp and paper production, they are used in bleaching stages where chlorinated compounds can severely corrode other alloys. Their durability in oxidizing and acidic solutions ensures long-term operation with minimal maintenance interruptions.

In the aerospace and marine sectors, Hastelloy C22 and C276 flanges are deployed in fuel handling systems, high-performance hydraulic circuits, and exhaust assemblies due to their ability to withstand aggressive chemical exposures and extreme temperature variations. The alloys’ resilience to seawater and brine solutions also makes them suitable for offshore and subsea systems, particularly where other materials would degrade quickly. Furthermore, their performance in flue gas desulfurization systems and pollution control equipment reinforces their value in environmental compliance applications, where resistance to sulfur dioxide, chlorides, and wet corrosive gases is vital.

Industry Use

Industries in India, the United Arab Emirates (UAE), the Kingdom of Saudi Arabia (KSA), Kuwait, Qatar, Oman, Iran, and Iraq increasingly depend on Hastelloy C22 and C276 flanges to meet the rigorous demands of their process systems. In the oil and gas sector, these flanges are integral to refining operations, chemical injection systems, and sour gas processing lines. Their proven performance in environments with high concentrations of hydrogen sulfide, chlorides, and organic acids helps prevent premature system failures and ensures long-term plant safety. Particularly in offshore extraction platforms and petrochemical refineries in the Gulf region, the materials’ corrosion resistance plays a pivotal role in minimizing downtime and ensuring regulatory compliance.

In power generation, especially in thermal, nuclear, and renewable energy plants, these flanges are used in heat recovery systems, condenser units, and fluid transfer pipelines exposed to acidic or high-temperature fluids. Given the intense focus on energy efficiency and infrastructure modernization across the Middle East and South Asia, the use of high-alloy materials such as Hastelloy is rapidly expanding. Governments and private operators in these regions prioritize materials that extend operational lifespans while reducing maintenance costs and environmental impact. As a result, Hastelloy C22 and C276 flanges are highly favored for both modern infrastructure projects and the enhancement of existing systems due to their long-term reliability and superior corrosion resistance.

Environmental engineering and water treatment sectors across these countries also benefit significantly from the deployment of Hastelloy flanges. In desalination plants, wastewater recycling facilities, and chemical effluent neutralization systems, the need for corrosion-resistant and low-maintenance components is critical. The alloys' longevity, coupled with their recyclability and compliance with global standards, supports broader sustainability goals and infrastructure resilience. As industrial growth accelerates across India and the Gulf nations, the adoption of advanced materials like Hastelloy continues to gain momentum, reinforcing the region’s transition toward safer, cleaner, and more efficient industrial ecosystems.

Our Hastelloy C22 / C276 Flanges are used in a wide range of applications and various industries. Below are a few of them: