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MATERIAL DATABASE

Special Alloys

Explore the range of special alloy grades used in Spiral Wound Gasket manufacturing for severe corrosion, high-temperature, chemical processing, marine and other demanding industrial applications. Compare corrosion resistance, mechanical properties, operating temperatures, international standards and engineering characteristics before selecting the appropriate material.

Why Special Alloys?

Special alloys are selected for Spiral Wound Gasket applications when conventional stainless steels and standard engineering alloys cannot provide the required combination of corrosion resistance, chemical compatibility, temperature capability or mechanical performance.

This material family includes high-alloy stainless steel, nickel-based corrosion-resistant alloys, titanium grades, zirconium and tantalum. These materials are used in aggressive chemical processing, seawater service, pharmaceutical equipment, acid handling, heat exchangers, aerospace systems and other critical sealing applications.

Available Special Alloy Grades

Select a special alloy grade to view detailed engineering information including chemical composition, mechanical properties, physical properties, operating temperature, heat treatment, international standards and typical applications.

250 SMO

250 SMO is a highly alloyed austenitic stainless steel developed for severe chloride-containing environments. Its high chromium, molybdenum and nitrogen content provides excellent resistance to pitting, crevice corrosion and stress corrosion cracking, making it suitable for demanding seawater, chemical processing and heat exchanger gasket applications.

UNS S31254 6Mo Stainless Steel High Chloride Resistance Austenitic

Alloy 20

Alloy 20 is a nickel-iron-chromium alloy developed primarily for resistance to sulfuric acid and other aggressive chemical environments. Its copper and molybdenum additions improve resistance to general corrosion, pitting and intergranular attack, making it useful for chemical processing, acid handling and pharmaceutical equipment.

ASTM B463 UNS N08020 Sulfuric Acid Service Ni-Fe-Cr Alloy

Hastelloy C-22

Hastelloy C-22 is a nickel-chromium-molybdenum alloy offering outstanding resistance to both oxidizing and reducing corrosive environments. It provides excellent resistance to pitting, crevice corrosion and stress corrosion cracking and is widely used for aggressive chemical processing and pollution-control equipment.

ASTM B575 UNS N06022 Ni-Cr-Mo Alloy Extreme Corrosion Resistance

Hastelloy C-276

Hastelloy C-276 is a nickel-molybdenum-chromium alloy with exceptional resistance to a wide range of severe chemical environments. It is particularly resistant to localized corrosion, chloride-induced stress corrosion cracking and aggressive oxidizing or reducing media.

ASTM B575 UNS N10276 Ni-Mo-Cr Alloy Severe Chemical Service

Tantalum

Tantalum provides exceptional resistance to many highly corrosive acids and chemical environments. Its outstanding chemical stability makes it a specialized material for extremely aggressive process media where conventional stainless steels and nickel alloys may not provide adequate corrosion resistance.

ASTM B708 Commercially Pure Tantalum Extreme Chemical Resistance Refractory Metal

Titanium Grade 2

Titanium Grade 2 is commercially pure titanium providing excellent corrosion resistance combined with low density and good mechanical properties. It is particularly effective in seawater, chloride-containing environments, oxidizing acids and chemical processing equipment.

ASTM B265 UNS R50400 Commercially Pure Titanium Excellent Seawater Resistance

Titanium Grade 5

Titanium Grade 5, commonly known as Ti-6Al-4V, is an alpha-beta titanium alloy offering high strength-to-weight ratio, excellent corrosion resistance and good fatigue performance. It is widely used in aerospace, chemical processing, marine and high-performance engineering applications.

ASTM B265 UNS R56400 Ti-6Al-4V High Strength

Zirconium

Zirconium offers exceptional resistance to highly corrosive chemical environments, particularly hydrochloric acid and other reducing media. Its strong resistance to localized corrosion makes it a specialized material for chemical reactors, heat exchangers and severe acid service.

ASTM B551 Zirconium Alloy Excellent Acid Resistance Chemical Processing

Typical Applications

Special alloy Spiral Wound Gasket materials are used where corrosion resistance, chemical compatibility, temperature capability and long-term reliability are critical.

Oil & Gas

High-pressure piping, offshore equipment, process systems and corrosive hydrocarbon service.

Chemical Plants

Chemical reactors, acid handling equipment, heat exchangers and aggressive process systems.

Petrochemical

Process piping, chemical processing equipment, refinery systems and high-temperature applications.

Power Generation

Heat exchangers, auxiliary systems and demanding high-temperature process equipment.

Marine & Offshore

Seawater piping, desalination systems and saltwater-cooled heat exchangers.

Pharmaceutical

High-purity processing equipment and specialized chemical service systems.

Why Choose Special Alloys?

Extreme Corrosion Resistance

Selected special alloys provide resistance to aggressive acids, chlorides, seawater and other severe chemical environments.

Demanding Temperature Service

Several grades provide reliable performance under elevated-temperature and demanding thermal conditions.

Engineering Flexibility

Different alloy systems allow gasket construction to be matched to specific process chemistry, temperature and mechanical requirements.

International Standards

Special alloy materials are available according to applicable ASTM, ASME, EN, DIN and other international material specifications.

Frequently Asked Questions

When should a special alloy be selected instead of stainless steel?

Special alloys should be considered when the process environment presents corrosion, chloride, acid, temperature or mechanical conditions beyond the practical capability of conventional stainless steel grades.

Which special alloy is suitable for severe chloride environments?

250 SMO, Titanium and selected nickel-based alloys can provide excellent resistance in chloride and seawater environments. The final selection depends on chloride concentration, temperature, aeration and other process conditions.

Which special alloy is suitable for aggressive chemical service?

Hastelloy C-22 and Hastelloy C-276 are commonly considered for highly aggressive chemical environments. Zirconium and Tantalum may be selected for specific severe acid services where their corrosion resistance provides an advantage.

Can special alloys be used as Spiral Wound Gasket winding materials?

Yes. Suitable special alloy strip materials can be used as the metallic winding element when their chemical compatibility, mechanical properties, thickness, forming characteristics and operating conditions are appropriate for the gasket design.

Need Help Selecting the Right Special Alloy?

Our engineering team can help select the most suitable special alloy for your operating pressure, temperature, process media and corrosion environment.

Contact Engineering