Valve Material Types
COMMON METAL TYPES USED IN VALVE MANUFACTURE
The following is a general review of common valve materials used in general industrial,
commercial and process valve construction.
Go to the Technical section of our website for a more detailed overview on the full range of
valve body and trim materials used in the construction of special service valves for oil & gas,
mining, petrochemical and critical service process control applications.
MATERIALS USED IN VALVE CONSTRUCTION
Aluminum - A non-ferrous metal, very lightweight, approximately one-third the weight of
steel. Aluminum exhibits excellent atmospheric corrosion resistance, but can be very reactive
with other metals. In valves, aluminum is mainly used as for exterior components such as a
hand wheels or identification tags.
Copper - Among the most important properties of wrought copper materials is their thermal
and electrical conductivity, corrosion resistance, wear resistance, and ductility. Wrought
copper performs well in high temperature applications and is easily joined by soldering or
brazing. Wrought copper is generally only used for fittings.
Bronze - One of the first alloys developed in the Bronze Age is generally accepted as the
industry standard for pressure rated bronze valves and fittings. Bronze has a higher strength
than pure copper, is easily cast, has improved machinability, and is very easily joined by
soldering or brazing. Bronze is very resistant to pitting corrosion, with general resistance to a
wide range of chemicals.
Silicone Bronze - Has the ductility of copper but much more strength. Silicon bronze has
equal or greater corrosion resistance to that of copper. Commonly used as a stem material in
pressure-rated valves, silicon bronze has greater resistance to stress corrosion cracking than
common brasses.
Aluminum Bronze - The most widely accepted disc material used in butterfly valves,
aluminum bronze is heat treatable and has the strength of steel. Formation of an
aluminum oxide layer on exposed surfaces makes this metal very corrosion resistant. Not
recommended for high pH wet systems.
Brass - Generally good corrosion resistance. Susceptible to de-zincification in specific
applications; excellent machinability. Primary uses for wrought brass are for ball valve stems
and balls, and iron valve stems. A forging grade of brass is used in commercial ball valve
bodies and end pieces.
Gray Iron - An alloy of iron, carbon and silicon; easily cast; good pressure tightness in the
as-cast condition. Gray iron has excellent dampening properties and is easily machined. It is
the standard material for bodies and bonnets of Class 125 iron body valves. Gray iron has
corrosion resistance that is improved over steel in certain environments.
Ductile Iron - Has composition similar to gray iron. Special treatment modifies metallurgical
structure, which yields higher mechanical properties; some grades are heat treated to
improve ductility. Ductile iron has the strength properties of steel using similar casting
techniques to that of gray iron and is used for class 250 (as well as class 125 in larger sizes).
Carbon Steel - Very good mechanical properties; good resistance to stress corrosion and
sulfides. Carbon steel has high and low temperature strength, is very tough and has excellent
fatigue strength. Mainly used in gate, globe, and check valves for applications up to 454ºC,
and in one-, two-, and three-piece ball valves. Can be forged or cast, with forgings being
superior especially for larges sizes in very high classes.
3% Nickel Iron - Improved corrosion resistance over gray and ductile iron. Higher
temperature as well as corrosion resistance and mechanical properties. Very resistant to
oxidising atmospheres.
Nickel-Plated Ductile Iron - Nickel coatings have received wide acceptance for use in
chemical processing. These coatings have very high tensile strength, 50 to 225 ksi. To
some extent, the hardness of a material is indicative of its resistance to abrasion and wear
characteristics. Nickel plating is widely specified as a disc coating for butterfly valves. For
industrial and petroleum ball valves, superior electroless nickel plating (ENP) is used in
carbon steel valve components and is in fact superior to stainless steel in hardness but with
similar corrosion properties
400 Series Stainless Steel - An alloy of iron, carbon, and chromium. This stainless is
normally magnetic due to its martensitic structure and iron-content. 400 series stainless
steel is resistant to high temperature oxidation and has improved physical and mechanical
properties over carbon steel. Most 400 series stainless steels are heat-treatable. The most
common applications in valves are, for stem material in butterfly valves, and trim components
such as seat, backseat bushings, discs, wedges etc. in cast steel gate, globe and check valves.
316 Stainless Steel - An alloy of iron, carbon, nickel, and chromium. A non-magnetic
stainless steel with more ductility than 400 series SS. Austenitic in structure, 316 stainless
steel has very good corrosion resistance to a wide range of environments, is not susceptible
to stress corrosion cracking (however it is not suitable for higher levels of H2S typically found
in wellhead applications) and is not affected by heat treatment. Very commonly used in valve
body and/or trim material.
17-4 PH Stainless Steel - Is a martensitic precipitation/age hardened stainless steel offering
high strength and hardness. 17.4 PH withstands corrosive attack better than any of the 400
series stainless steels and in most conditions its corrosion resistance closely approaches that
of 300 series stainless steel. 17.4 PH is primarily used as a stem material for butterfly and
ball valves as well as any valve application requiring a superior strength stem.
Alloy 20Cb-3 - This alloy has higher amounts of nickel and chromium than 300 series
stainless steel and with the addition of columbium, this alloy retards stress corrosion cracking
and has improved resistance to sulfuric acid. Alloy 20 is widely used in all phases of chemical
processing.
Monel - Is a nickel-copper alloy used primarily as interior trim on all types of valves. One of
the most specified materials for corrosion resistance to sea and salt water. Monel is also very
resistant to strong caustic solutions.
Stellite - Cobalt base alloy, one of the best all-purpose hard facing alloys. Very resistant to
heat, abrasion, corrosion, impact, galling, oxidation, thermal shock and erosion. Stellite takes
a high polish and is used in steel valve seat rings. Normally applied with transfer plasma-arc;
Stellite hardness is not affected by heat treatment.
Hastelloy C - A high nickel-chromium molybdenum alloy, which has outstanding resistance
to a wide variety of chemical process environments including strong oxidisers such as wet
chlorine, chlorine gas, and ferric chloride. Hastelloy C is also resistant to nitric, hydrochloric,
and sulfuric acids at moderate temperatures.
The following is a general review of common valve materials used in general industrial,
commercial and process valve construction.
Go to the Technical section of our website for a more detailed overview on the full range of
valve body and trim materials used in the construction of special service valves for oil & gas,
mining, petrochemical and critical service process control applications.
MATERIALS USED IN VALVE CONSTRUCTION
Aluminum - A non-ferrous metal, very lightweight, approximately one-third the weight of
steel. Aluminum exhibits excellent atmospheric corrosion resistance, but can be very reactive
with other metals. In valves, aluminum is mainly used as for exterior components such as a
hand wheels or identification tags.
Copper - Among the most important properties of wrought copper materials is their thermal
and electrical conductivity, corrosion resistance, wear resistance, and ductility. Wrought
copper performs well in high temperature applications and is easily joined by soldering or
brazing. Wrought copper is generally only used for fittings.
Bronze - One of the first alloys developed in the Bronze Age is generally accepted as the
industry standard for pressure rated bronze valves and fittings. Bronze has a higher strength
than pure copper, is easily cast, has improved machinability, and is very easily joined by
soldering or brazing. Bronze is very resistant to pitting corrosion, with general resistance to a
wide range of chemicals.
Silicone Bronze - Has the ductility of copper but much more strength. Silicon bronze has
equal or greater corrosion resistance to that of copper. Commonly used as a stem material in
pressure-rated valves, silicon bronze has greater resistance to stress corrosion cracking than
common brasses.
Aluminum Bronze - The most widely accepted disc material used in butterfly valves,
aluminum bronze is heat treatable and has the strength of steel. Formation of an
aluminum oxide layer on exposed surfaces makes this metal very corrosion resistant. Not
recommended for high pH wet systems.
Brass - Generally good corrosion resistance. Susceptible to de-zincification in specific
applications; excellent machinability. Primary uses for wrought brass are for ball valve stems
and balls, and iron valve stems. A forging grade of brass is used in commercial ball valve
bodies and end pieces.
Gray Iron - An alloy of iron, carbon and silicon; easily cast; good pressure tightness in the
as-cast condition. Gray iron has excellent dampening properties and is easily machined. It is
the standard material for bodies and bonnets of Class 125 iron body valves. Gray iron has
corrosion resistance that is improved over steel in certain environments.
Ductile Iron - Has composition similar to gray iron. Special treatment modifies metallurgical
structure, which yields higher mechanical properties; some grades are heat treated to
improve ductility. Ductile iron has the strength properties of steel using similar casting
techniques to that of gray iron and is used for class 250 (as well as class 125 in larger sizes).
Carbon Steel - Very good mechanical properties; good resistance to stress corrosion and
sulfides. Carbon steel has high and low temperature strength, is very tough and has excellent
fatigue strength. Mainly used in gate, globe, and check valves for applications up to 454ºC,
and in one-, two-, and three-piece ball valves. Can be forged or cast, with forgings being
superior especially for larges sizes in very high classes.
3% Nickel Iron - Improved corrosion resistance over gray and ductile iron. Higher
temperature as well as corrosion resistance and mechanical properties. Very resistant to
oxidising atmospheres.
Nickel-Plated Ductile Iron - Nickel coatings have received wide acceptance for use in
chemical processing. These coatings have very high tensile strength, 50 to 225 ksi. To
some extent, the hardness of a material is indicative of its resistance to abrasion and wear
characteristics. Nickel plating is widely specified as a disc coating for butterfly valves. For
industrial and petroleum ball valves, superior electroless nickel plating (ENP) is used in
carbon steel valve components and is in fact superior to stainless steel in hardness but with
similar corrosion properties
400 Series Stainless Steel - An alloy of iron, carbon, and chromium. This stainless is
normally magnetic due to its martensitic structure and iron-content. 400 series stainless
steel is resistant to high temperature oxidation and has improved physical and mechanical
properties over carbon steel. Most 400 series stainless steels are heat-treatable. The most
common applications in valves are, for stem material in butterfly valves, and trim components
such as seat, backseat bushings, discs, wedges etc. in cast steel gate, globe and check valves.
316 Stainless Steel - An alloy of iron, carbon, nickel, and chromium. A non-magnetic
stainless steel with more ductility than 400 series SS. Austenitic in structure, 316 stainless
steel has very good corrosion resistance to a wide range of environments, is not susceptible
to stress corrosion cracking (however it is not suitable for higher levels of H2S typically found
in wellhead applications) and is not affected by heat treatment. Very commonly used in valve
body and/or trim material.
17-4 PH Stainless Steel - Is a martensitic precipitation/age hardened stainless steel offering
high strength and hardness. 17.4 PH withstands corrosive attack better than any of the 400
series stainless steels and in most conditions its corrosion resistance closely approaches that
of 300 series stainless steel. 17.4 PH is primarily used as a stem material for butterfly and
ball valves as well as any valve application requiring a superior strength stem.
Alloy 20Cb-3 - This alloy has higher amounts of nickel and chromium than 300 series
stainless steel and with the addition of columbium, this alloy retards stress corrosion cracking
and has improved resistance to sulfuric acid. Alloy 20 is widely used in all phases of chemical
processing.
Monel - Is a nickel-copper alloy used primarily as interior trim on all types of valves. One of
the most specified materials for corrosion resistance to sea and salt water. Monel is also very
resistant to strong caustic solutions.
Stellite - Cobalt base alloy, one of the best all-purpose hard facing alloys. Very resistant to
heat, abrasion, corrosion, impact, galling, oxidation, thermal shock and erosion. Stellite takes
a high polish and is used in steel valve seat rings. Normally applied with transfer plasma-arc;
Stellite hardness is not affected by heat treatment.
Hastelloy C - A high nickel-chromium molybdenum alloy, which has outstanding resistance
to a wide variety of chemical process environments including strong oxidisers such as wet
chlorine, chlorine gas, and ferric chloride. Hastelloy C is also resistant to nitric, hydrochloric,
and sulfuric acids at moderate temperatures.
