STAINLESS VALVE GRADES
STAINLESS & ALLOY STEEL FOR VALVE CONSTRUCTION
The following is a list of stainless steels commonly used in valve construction. This list includes types of stainless steels as well as cross references of equivalent types of cast and forged stainless steel grades covering ASTM and EN, and valve standards associated to them.
CHROME-NICKEL AUSTENITIC STAINLESS STEELS
- Carbon (C): from 0.03% to 0.25% (“L” indicates low content of carbon <0.035%)
- Chromium (Cr): from 17% to 26%
- Nickel (Ni): from 7% to 22%
- Good mechanical properties
- High resiliency at low temperatures (-200ºC).
- Suitable for cryogenic processes.
- “L” used for welding.
- 70% of stainless steel production is austenitic.
FERRITIC STAINLESS STEEL
- Carbon (C): from <0.1% (up to 0.35% for 0.30% chromium content)
- Chromium (Cr): from 16% to 30%
- Better mechanical characteristics than austenitics, but worse corrosion resistance
- Generally lower cost
- Better chemical resistance than martensitic stainless steels
MARTENSITIC STAINLESS STEEL
- Carbon (C): from 0.1% to 0.5%
- Chromium (Cr): from 12% to 17%
- Better mechanical charateristics than austenitics and ferritics, but lower corrosion resistance
- Highly machineable
- Good resistance to corrosion from weak acids.
- Mechanical properties can be modfiied with thermal treatments
DUPLEX STAINLESS STEEL
- Chromium (Cr): from 19% to 28%
- Molybdenum (Mo): up to 5%
- Nickel (Ni): 4.5-6.5%
- Magnesium (Mg): 2%
- Duplex Steels are a mix of austenitic stainless steel (about 40% to 50%) and feritic steel (about 50% to 60%).
- Good mechanical properties and corrosion resistance. Refer below cross reference chart valve ASTM duplex grades and equivalent cast and forged materials.
(A) S31802 has been supplemented by S32205 (F60) which has a higher minimum Ni. Cr and Mo
(B) Not referenced in ANSI B16.34 – 2009
(C) A890 optionally superseded by A995. A995 does not reference 1A or 1C
(D) Not referenced in A995
Also click here for alternation Duplex Cross Reference
STAINLESS AND ALLOY STEEL STANDARDS FOR VALVES
ASTM A217 / A217M – 08
Standard Specification for Steel Castings, Martensitic Stainless and Alloy, for Pressure Containing Parts, Suitable for High-Temperature Service
This specification covers steel castings, martensitic stainless steel and allow steel castings for valves, flanges, fittings and other pressure-containing parts intended primarily for high-temperature and corrosive service. These grades of steels covered here are: Grade WC1, Grade WC4, Grade WC5, Grade WC6, Grade WC9, Grade WC11, Grade C5, Grade C12, Grade C12A and tempering for all other grades. Heat treatments shall be performed after castings have been allowed to cool. Heat and product analyses shall be performed wherein specimens shall conform to required chemical composition of carbon, molybdenum, chromium, nickel, vanadium, manganese, phosphorus, sulfur, silicon, columbium, nitrogen, aluminum, copper, titanium, tungsten, and zirconium. The surface of the casting shall be nexamined visually and shall be free of adhering sand, scale, cracks and hot tears. Steels shall undergo tension test, and shall conform to the following mechanical requirements: tensile strength, yield strength, elongation and reduction of area.
ASTM A351 / A351M – 10
Standard Specification for Castings, Austenitic, for Pressure-Containing Parts
This specification covers austenitic steel castings for valves, flanges, fittings, and other pressure-containing parts. The steel shall be made by the electric furnace process with or without separate refining such as argon-oxygen decarburization. All castings shall receive heat treatment followed by quench in water or rapid cool by other means as noted. the steel shall conform to both chemical composition and tensile property requirements.
ASTM A182 / A182M – 09a
Standard Specification for Forged or Rolled Allow and Stainless Steel Pipe Flanges, Forged Fittings and Valves and Parts for High-Temperature Service
This specification covers forged or rolled alloy and stainless steel pipe flanges, forged fittings, and valves and parts for high-temperature service. After hot working, forgings shall be cooled to a specific temperature prior to heat treatment, which shall be performed in accordance with certain requirements such as heat treatment type, austenitizing/solution temperature, cooling media and quenching. the materials shall conform to the required molybdenum, columbium, titanium. The material shall conform to the requirements as to mechanical properties for the grade ordered such as tensile strength, yield strength, elongation, brinell hardness. All H grades and grade F63 shall be tested for average grain size.
ASTM A995 / A995M – 09
Standard Specification for Castings, Austenitic-Ferritic (Duplex) Stainless Steel, for Pressure-Containing Parts
This specification covers austenitic-ferritic (duplex) stainless steel castings for valves, flanges, fittings, and other pressure-containing parts. The grades of steels covered here are: Grade 1B, Grade 2A, Grade 3A, Grade 4A, Grade 5Aand Grade 6A. The steel castings shall be heat treated up to required temperature and shall undergo water quenching or rapid cooling by other means after heating. Heat and product analyses shall be performed wherein specimens shall conform to required chemical composition of carbon, manganese, silicon, phosporous, sulfur, chromium, nickel, molybdenum, copper, tungsten and nitrogen. All steels shall undergo tension test and shall conform to the following mechanical requirements: tensile strength, yield strength and elongation.
ASTM A240 / A240M – 10
Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications.
This specification covers chromium, chromium-nickel, and chromium-manganese-nickel stainless steel plate, sheet and strip for pressure vessels and for general applications. The steel shall conform to the requirements as to chemical composition specified. The material shall conform to the mechanical properties specified.
ASTM A872 / A872M – 07a
Standard Specification for Centrifugally Cast Ferritic/Austenitic Stainless Steel Pipe for Corrosive Environments
This specification covers centrifugully cast ferritic/austenitic steel pipe intended for general corrosive service. These steels are susceptible to embrittlement if used for prolonged periods at elevated temperatures. The pipe shall be made by centrifugal casting process and furnished in the specified heat-treatment condition. The pipe shall also be machined. The grades shall conform to the required chemical composition for carbon, manganese, phosphorous, sulfur, silicon, nickel, chromium, molybdenum, nitrogen, copper and cobalt. Heat analysis and product analysis shall be done. Tensile requirements shall conform to the specified tensile strength, yield strength and elongation; and hardness requirements shall conform to the specified Brinell and Rockwell C Values. Tension test shall also be made.
ASTM A403 / A403M – 09
Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings
This specification covers the standard for wrought austenitic stainless steel fittings for pressure piping applications. The material for fittings shall consist of forgings, bars, plates, or seamless or welded tubular products. Forgings or shaping operations shall be performed by hammering, pressing, piercing, extruding, upsetting, rolling, bending, fusion welding, machining, or by a combination of two or more of these operations. All fittings shall undergo heat-treatment. Chemical and product analyses shall be performed and shall conform tot the required chemical composition in carbon, manganese, phosphorous, sulfur, silicon, chromium, molybdenum, and titanium. Tension test shall be done on the fitting material to determine the tensile properties such as yield strength and tensile strength. Fittings supplied under this specification shall be examined visually for surface discontinuities, surface checks, and mechanical marks.
ASTM A473 / A743M – 06
Standard Specification for Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant for General Applications
This specification covers iron-chromium and iron-chromium-nickel alloy castings for general corrosion-resistant application. The grades of these castings represent types of allow castings suitable for broad ranges of application which are intended for a wide variety of corrosion environments. The steel shall be made by the electric furnace process with or without separate refining such as argon-oxygen decarburization. The castings shall be subjected to heat treatment.
ASTM A744 / A744M – 06
Standard Specification for Casting, Iron-Chromium-Nickel, Corrosion Resistant for Severe Service
This specification covers standard requirements for iron-chromium-nickel alloy, stainless steel castings intended for particularly severe corrosive applications. Alloys shall be melted by the electric furnace process with or without refining such as argon-oxygen-decarburization. Castings shall be heat treated and shall conform to the required heat treatment conditions. The materials shall conform with the prescribed chemical requirements for carbon, copper, selenium, tungsten, vanadium, iron and nitrogen
ASTM A890/ A890M-99(2007)
Standard Specification for Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex (Austenitic/Ferritic) for General Applications
This specification covers castings, iron-chromium-nickel-molybdenum corrosion-resistant, duplex (austenitic/ferritic) for general application. Castings shall be heat treated in accordance with the required procedure and heat-treat temperature. Proper heat treatment of these alloys is usually necessary to enhance corrosion resistance and in some case to meet mechanical properties. Minimum heat-treat temperatures are specified; however it is sometimes necessary to heat-treat at higher temperatures, hold for some minimum time at temperature and then rapidly cool the castings in order to enhance the corrosion resistance and meet there require mechanical properties. The steel shall conform to the required chemical composition for carbon, manganese, silicon, phosphorous, sulfur, chromium, nickel, molybdenum, copper, tungsten and nitrogen. Castings shall be marked for material identification with the specification designation and grade.
ASTM A276 – 08A
Standard Specification for Stainless Steel Bars and Shapes
This specification covers hot-finished or cold-finished bars except bars for reforging. It includes rounds, squares and hexagons and hot-rolled or extruded shapes, such as angles, tees, and channels in the more commonly used types of stainless steels. The bars shall be furnished in one of the following conditions: Condition A in which the bars are annealed, Condition H in which the bars are hardened and tempered at a relative temperature, Condition T in which the bars are hardened and tempered at a relatively high temperature, Condition S in which the bars are strain hardened or relatively light cold worked, and Condition B in which the bars are relatively sever cold worked. The material shall be subjected to a mechanical test to determine its tensile strength, yield strength, elongation, and Brinell hardness.
Technical Delivery Conditions for Steel Castings for Pressure purposes
Part 4: Austenitic and austenitic-ferritic steel grades (Q)
EN 10213:2007 applies to steel castings for pressure containing parts. It includes materials which are used for the manufacture of components for pressure equipment.
EN 10213:2007 relates to castings characterised by their chemical composition and mechanical properties. It apples where castings are joined by welding by the founder.
EN 10213:2007 does not apply in cases where castings are welded to wrought products (plates, tubes, forgings) or by non founders.
Typical Austenitic Stainless Steel Grades – 19%Cr + 10% Ni have been adopted in corrosion resistant application for decades. In accordance with more stringent service demands. Austenitic stainless steel is not suitable for more severe environments. Stronger and more corrosion resistant materials are available. Valves in materials like Alloy 20, Hastelloy, Monel & Duplex are stocked and now supplied by GSL.
ANTI CORROSIVE STEEL CATEGORIES
Effect of Major Alloying Elements
A stainless steel contains a minimum of 10.5% chromium because this level of chromium causes the spontaneous formation of a stable, transparent passive, protective film. Increasing the lvel of chromium enhances corrosion resistance. At elevated temperatures, chromium provides resistance to oxidation and sulfur-containing and other corrosive atmostpheres; contributes to high temperature creep and rupture strength; and, in come alloys, increases resistance to carburization.
Nickel in stainless steel promotes the stability of austenite. Austenite is stronger and more stable at higher temperatures then ferrite. Less nicke is needed to retain an austenitic structure as the nitrogen or carbon levels increase. When sufficient nickel is added to a chromium stainless steel, the structure changes from ferritic to austenitic. Adding nickel improves toughness, ductility and weldability. Nickel increases resistance to oxidation, carburization, nitriding, thermal fatigue and strong acids, particularly reducing acids. it is an important alloying element in stainless steel and nickel-base alloys used for corrosive and high temperature applications.
Molybdenum additions improve resistance to pitting and crevice corrosion in chloride containing environments and corrosion by sulfuric, phosphoric and hydrochloric acids. The elevated temperature mechanical properties of austenitic stainless steels and the strength.
APPLICATION AND SELECTION OF STAINLESS STEEL MATERIAL
GSL keeps large stocks of Gate, Globe and Check valves as well as Ball Valves, Plug Valves and Strainers in 316, 304 Duplex, Alloy 20 etc. in class 150 and above in all sizes. See stock list at our website click here.
At Global Supply Line the same knowledge and effort we put into the website goes into every product we sell. If this website helps you, please reward GSL with your business.
If we don’t have the valves in stock we can source it from our overseas network of stockists and very short lead-time specialty manufacturers. We can even supply exotic grades like Nickel, Super Duplex F55 and Monel (ASTM A494-M35-1) Cd4M-Cu, Hastealloy C (ASTM A-494 CW12MW), 137 (C8G8M) in short lead-time.
For cross reference tables and charts of ASTM/ANSI specifications covering equipment materials used for valves, flanges & fittings: click here