A cast valve is a mechanical device featuring a cast steel body, i.e. a body manufactured by casting liquid metals into molds. Cast valve bodies are common for valves above 2 inches in diameter (for smaller bore sizes, forged valves are either preferred or the only option). The ASTM A216 and the ASTM A351 specifications cover materials for carbon, alloy, and stainless steel cast valves. Cast body materials are cheaper than forged bodies but are less resilient.
ASTM A216 CARBON STEEL VALVE
This ASTM specification covers 3 grades of carbon steel (WCA, WCB, and WCC), in terms of chemical composition and mechanical properties.
The grade selection depends on the system design and the service conditions, which affect the required mechanical properties and hence the needed grade. The ASTM A216 specification covers carbon steel castings for valves, flanges, fittings, and other pressure-containing parts for high-temperature service and of a quality suited for assembly with other castings or wrought steel parts by fusion welding.
ASTM A216 steel castings shall be heat treated and can be manufactured in the annealed, or normalized, or normalized and tempered conditions. The surface of steel castings shall be free of adhering elements such as sand, cracks, hot tears, and other defects.
|ASTM A216 carbon steel valves, chemical composition|
|ASTM A216 GRADE||C||Mn||P||S||Si||Cu||Ni||Cr||Mo||V|
|WCA UNS J02502||0.25(1)||0.70(1)||0.04||0.045||0.60||0.30||0.50||0.50||0.20||1.00|
|WCB UNS J03002||0.30(2)||1.00(2)||0.04||0.045||0.60||0.30||0.50||0.50||0.20||1.00|
|WCC UNS J02503||0.25(3)||1.20(3)||0.04||0.045||0.60||0.30||0.50||0.50||0.20||1.00|
- For each reduction of 0.01% below the specified maximum Carbon content, an increase of 0.04% manganese above the specified maximum is allowed up to a maximum of 1.10%.
- For each reduction of 0.01% below the specified maximum Carbon content, an increase of 0.04% Mn above the specified maximum is allowed up to a maximum of 1.28%.
- For each reduction of 0.01% below the specified maximum Carbon content, an increase of 0.04% manganese above the specified maximum is allowed to a maximum of 1.40%.
ASTM A351 STAINLESS STEEL VALVE
ASTM A351 covers austenitic steel castings for valves, flanges, fittings, and other pressure-containing parts. The most common grades are ASTM A351 CF3, CF8 (SS304), and CF8M (SS316).
The steel shall be made by the electric furnace process with or without separate refining such as argon-oxygen decarburization.
Any ASTM A351 cast part shall receive heat treatment followed by a quench in water or rapid cooling. The steel shall conform to the chemical and mechanical requirements set by the specification.
|ASTM A351 stainless steel valves, chemical composition|
|ASTM A351 GRADE||UNS||C||Mn||Si||S||P||Cr||Ni||Mo||Nb||V||N||Cu|
|CF8C||J92710||0.08||1.5||2.0||0.040||0.040||18.0-21.0||9.0-12.0||0.50||( 1 )|
|CF10MC||0.10||1.50||1.50||0.040||0.040||15.0-18.0||13.0-16.0||1.7-2.25||( 2 )|
- Grade CF8C shall have a Niobium content 8 times above the Carbon but not over 1.00%.
- Grade CF10MC shall have a Niobium content 10 times above the Carbon but not over 1.20%.
ASTM A216, ASTM A351 MECHANICAL PROPERTIES
|Material Code and Description||Minimum Steel Mechanical Properties||Modulus||Approximate|
|MATERIAL GROUP||ASTM CAST GRADE||Tensile strength (psi)||Yield strength (psi min)||Elongation at 2 inches||Reduction of Area (%)|
|Carbon Steel||ASTM A216 Grade WCB||70,000||36,000||22||35||27.9||137-1 87|
|Carbon Steel||ASTM A352 Grade LCB||65,000||35,000||24||35||27.9||137-1 87|
|Chrome Moly Steel||ASTM A217 Grade C5||90,000||60,000||18||35||27.4||241 Max.|
|Carbon Moly Steel||ASTM A217 Grad e WC1||65,000||35,000||24||35||29.9||215 Max.|
|Chrome Moly Steel||ASTM A217 Grade WC6||70,000||40,000||20||35||29.9||215 Max.|
|Chrome Moly Steel||ASTM A217 Grade WC9||70,000||40,000||20||35||29.9||241 Max.|
|3 1/2% Nickel Steel||ASTM A352 Grade LC3||65,000||40,000||24||35||27.9||137|
|Chrome Moly Steel||ASTM A217 Grade C12||90,000||60,000||18||35||27.4||180-240|
|Stainless Steel Type 304||ASTM A351 Grade CF-8||65,000||28,000||35||–||28||140|
|Stainless Steel Type 316||ASTM A351 Grade CF-8M||70,000||30,000||30||–||28.3||156-170|
|Cast Iron||ASTM A126 Class B||31,000||–||–||–||–||160-220|
|Cast Iron||ASTM A126 Class C||41,000||–||–||–||–||160-220|
|Ductile Iron||ASTM A395 Type 60-45-15||60,000||45,000||15||–||23-26||143-207|
|Ductle Ni-Resist Iron (500 KG Load)||ASTM A439 Type D-2B||58,000||30,000||7||–||–||148-211|
|Standard Valve Bronze||ASTM B62||30,000||14,000||20||17||13.5||55-65*|
|Tin Bronze||ASTM B143 Alloy 1A||40,000||18,000||20||20||15||75-85*|
|Manganese Bronze||ASTM B147 Alloy 8A||65,000||25,000||20||20||15.4||98*|
|Aluminum Bronze||ASTM B148 Alloy 9C||75,000||30,000||12 min.||12||17||150|
|Mondel Alloy 411||(Weldable Grade)||65,000||32,500||25||–||23||120-170|
|Nickel Moly Alloy B||ASTM A494 (Hastelloy B)||72,000||46,000||6||–||–||–|
|Nickel Moly Chrome Alloy C||ASTM A494 (Hastelloy C)||72,000||46,000||4||–||–||–|
|Cobalt-base Alloy No. 6||Stellite No. 6||121,000||64,000||01.feb||–||30.4||–|
|Aluminum Bar||ASTM B211 Alloy 20911-T3||44,000||36,000||15||–||10.2||95|
|Yellow Brass Bar||ASTM B16 1/2 Hard||45,000||15,000||7||50||14||–|
|Naval Brass Bar||ASTM B21 Alloy 464||60,000||27,000||22||55||–||–|
|Leaded Steel Bar||AISI 12L 14||79,000||71,000||16||52||–||163|
|Carbon Steel Bar||ASTM A108 Grade 1018||69,000||48,000||38||62||–||143|
|AISI 4140 Chrome Moly Steel||(Suitable for ASTM A193 Grade B7 bolt material)||135,000||115,000||22||63||29.9||255|
|Stainless Steel Type 302||ASTM A276 Type 302||85,000||35,000||60||70||28||150|
|Stainless Steel Type 304||ASTM A276 Type 304||85,000||35,000||60||70||–||149|
|Stainless Steel Type 316||ASTM A276 Type 316||80,000||30,000||60||70||28||149|
|Stainless Steel Type 316L||ASTM A276 Type 316L||81,000||34,000||55||–||–||146|
|Stainless Steel Type 410||ASTM A276 Type 410||75,000||40,000||35||70||29||155|
|Stainless Steel Type 17-4PH||ASTM A461 Grade 630||135,000||105,000||16||50||29||275-345|
|Nickel Copper Alloy Bar||Alloy K500 (K Monel)||100,000||70,000||35||–||26||175-260|
|Nickel Moly Alloy B Bar||ASTM B335 (Hastelloy B)||100,000||46,000||30||–||–||–|
|Nickel Moly Alloy C Bar||ASTM B336 (Hastelloy C)||100,000||46,000||20||–||–||–|
CAST VALVE MATERIAL SELECTION
The table shows the most common materials for cast valves and their recommended service:
|MATERIAL GROUP||MATERIAL GRADE||RECOMMENDED SERVICE|
|High-temperature Carbon Steel||ASTM A216 Grade WCB||Non-corrosive fluids as water, oil, and gases at temperatures range -20°F (-30°C) and +800°F (+425°C)|
|Low-temperature Carbon Steel||ASTM A352 Grade LCB||Low temperature to -50°F (-46°C). Use excluded above +650°F (+340°C).|
|Low-temperature Carbon Steel||ASTM A352 Grade LC1||Low temperature to -75°F (-59°C). Use excluded above +650°F (+340°C).|
|Low-temperature Carbon Steel||ASTM A352 Grade LC2||Low temperature to -100°F (-73°C). Use excluded above +650°F (+340°C).|
|3.1/2% Nickel Steel||ASTM A352 Grade LC3||Low temperature to -150°F (-101°C). Use excluded above +650°F (+340°C).|
|1.1/4% Chrome 1/2% Moly Steel||ASTM A217 Grade WC6||Non-corrosive fluids as water, oil, and gases at temperatures range -20°F (-30°C) and +1100°F (+593°C).|
|2.1/4% Chrome||ASTM A217 Grade C9||Non-corrosive fluids as water, oil and gases at temperatures range -20°F (-30°C) and +1100°F (+593°C).|
|5% Chrome 1/2% Moly||ASTM A217 Grade C5||Mild corrosive or erosive applications and non-corrosive applications at temperatures between -20°F (-30°C) and +1200°F (+649°C).|
|ASTM A217 Grade C12||Mild corrosive or erosive applications and non-corrosive applications at temperatures between -20°F (-30°C) and +1200°F (+649°C).|
|12% Chrome Steel||ASTM A487 Grade CA6NM||Corrosive application at temperatures between -20°F (-30°C) and +900°F (+482°C).|
|12% Chrome||ASTM A217 Grade CA15||Corrosive application at temperatures up to +1300°F (+704°C)|
|Stainless steel 316||ASTM A351 Grade CF8M||Corrosive or either extremely low or high-temperature non-corrosive services between -450°F (-268°C) and +1200°F (+649°C). Above +800°F (+425°C) specify carbon content of 0.04% or greater.|
|Stainless steel 347||ASTM 351 Grade CF8C||Mainly for high temperature, corrosive applications between -450°F (-268°C) and +1200°F (+649°C). Above +1000°F (+540°C) specify carbon content of 0.04% or greater.|
|Stainless steel 304||ASTM A351 Grade CF8||Corrosive or extremely high temperatures non-corrosive services between -450°F (-268°C) and +1200°F (+649°C). Above +800°F (+425°C) specify carbon content of 0.04% or greater.|
|Stainless steel 304L||ASTM A351 Grade CF3||Corrosive or non-corrosive services to +800F (+425°C).|
|Stainless steel 316L||ASTM A351 Grade CF3M||Corrosive or non-corrosive services to +800F (+425°C).|
|Alloy-20||ASTM A351 Grade CN7M||Good resistance to hot sulfuric acid to +800F (+425°C).|
|Monel||ASTM 743 Grade M3-35-1||Weldable grade. Good resistance to corrosion by all common organic acids and salt water. Also highly resistant to most alkaline solutions to +750°F (+400°C).|
|Hastelloy B||ASTM A743 Grade N-12M||Well suited for handling hydrofluoric acid at all concentrations and temperatures. Good resistance to sulphuric and phosphoric acids to +1200°F (+649°C).|
|Hastelloy C||ASTM A743 Grade CW-12M||Good resistance to span oxidation conditions. Good properties at high temperatures. Good resistance to sulphuric and phosphoric acids to +1200°F (+649°C).|
|Inconel||ASTM A743 Grade CY-40||Very good for high-temperature service. Good resistance to spangly corrosive media and atmosphere to +800°F (+425°C).|
|Bronze||ASTM B62||Water, oil or gas: up to 400°F. Excellent for brine and seawater service.|