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Steel Grades

Regular Temp Steel
Low Temp Steel
Stainless Steel
Speciality Trims
Heat Treatment
ASTM A216/A216M (WCA, WCB, WCC) (A105 is the forged version of this steel) - Typically referred to as a cast regular temp or reg temp steel.

For each grade WC - stands for "wrought carbon" with the third letter indicating grade - the higher the grade the higher the tensile/yield strength.

This specification covers carbon steel castings for valves, fittings, flanges and other pressure-containing parts for high temperature service and the quality required for assembly with other castings or wrought steel parts by fusion welding. These grades are all "cast" grades meaning they are made through "casting" which is a manufacturing process where a liquid material is poured into a mold and allowed to harden. Cast valves are typically less expensive than their forged counterparts for larger bore valves - though as a result of the casting process there is the potential for a porous cast (bad casting) which is why most high pressure valves are made with forged steel. NACE MR-0175 requires the use of double heat-treated cast steel castings.

The following table indicates the mechanical properties and chemical composition of the three ASTM 216/A216M grades.

Of the three steel grades WCB is the common grade for regular temperature applications for cast steel valves. ASTM-A216 WCB is acceptable for the temperature range of -20*F to 800*F (where corrosion resistance is not important). Other grades of wrought carbon exist for specific applications - copies of these grades can be purchased at www.astm.org

ASTM A352/A352M (LCA, LCB, LCC) (ASTM A350 LF2 is the forged version of this steel) - Typically referred to as a cast low temp steel.

For each grade LC - stands for " low temp (wrought) carbon" with the third letter indicating grade - the higher the grade the higher the tensile/yield strength.

This specification covers carbon steel castings for valves, fittings, flanges and other pressure-containing parts for low temperature service and the quality required for assembly with other castings or wrought steel parts by fusion welding. These grades are all "cast" grades meaning they are made through "casting" which is a manufacturing process where a liquid material is poured into a mold and allowed to harden. Cast valves are typically less expensive than their forged counterparts for larger bore valves - though as a result of the casting process the potential for a porous cast (bad casting) is why most high pressure valves are made with forged steel. NACE MR-0175 requires the use of double heat-treated cast steel castings.

The following table indicates the mechanical properties and chemical composition of the three ASTM A352/A352M grades.



Of the three steel grades LCC is the common grade for regular temperature applications for cast steel valves. These three grades of ASTM A352/A352M are good for temperatures ranging from -50*F to 800* F (where corrosion resistance is not important) Other grades of low temp wrought carbon exist for specific applications - copies of these grades can be purchased at www.astm.org

ASTM A351/A351M - CF8M (ASTM A182 - 316SS is the forged version of this steel) - Typically referred to as stainless cast steel

CF8M is a casting austenitic-ferritic stainless steel grade with high carbon, nickel and molybdenum compared to other CF stainless grades.

This specification covers stainless steel castings for valves, fittings, flanges and other pressure-containing parts for low temperature service and the quality required for assembly with other castings or wrought steel parts by fusion welding. These grades are all "cast" grades, meaning they are made through "casting", a manufacturing process where a liquid material is poured into a mold and allowed to harden. Cast valves are typically less expensive than their forged counterparts for larger bore valves - though as a result of the casting process the potential for a porous cast (bad casting) is why most high pressure valves are made with forged steel. CF8M meets NACE MR-0175 requirements without double-heat treatment.

The following table indicates the mechanical properties and chemical composition of ASTM A351/A351M grades CF8M


ASTM A351/A351M grade CF8M is good for temperatures ranging from absolute zero to 1500* F. CF8M is used in applications where corrosion resistance is a primary concern. Other grades of cast stainless steels exist for specific applications - copies of these grades can be purchased at www.astm.org

A276- 410 or A276 -410 Hard Faced - This is the basic martensitic stainless that attains high mechanical properties after heat treatment typically used in valve components.

ASTM A276 - 410 can be hardened by heating the steel to 1870 - 1850 *F (954 - 1010 *C) oil quench for maximum hardness. This grade of steel provides good impact strength, and corrosion/scaling resistance up to 1200 *F. Like most stainless material this steel is good from absolute zero to about 1200 *F A copy of this grade can be purchased at www.astm.org

Specialty Trims/Material -

Stellite - is a proprietary alloy used for demanding mechanical and chemical service over a wide temperature range. Stellite retains a reasonable level of hardness up to 1470 * F and is known for its anti-galling properties, high temperature hardness and a strong resistance to impact/cavity corrosion. Stellite 6 is the most common form of stellite in valves. Stellite is trademarked by Deloro Stellite Company.

For more information on Stellite visit http://www.stellite.com/alloydatabase/nominal.asp

Inconel - Inconel is a family of austenitic nickel-chromium based superalloys. It is typically used in high temperature applications and is well suited for extreme service environments. Inconel is trademarked by Special Metals Corporation.

For more information on Inconel visit http://www.specialmetals.com/products/index.php

Monel - Monel is a series of nickel alloys with up to 67% nickel with high copper and trade amounts of iron and other elements. Monel is also trademarked by Special Metals Corporation and is typically used in high corrosion environments like in seawater valves.

For more information on Monel visit http://www.specialmetals.com/products/index.php

ENC - Electroless nickel coating or ENP - Electroless nickel plating (ASTM B733)

Electroless nickel coating/plating is an autocatalytic nickel-phosphorous coating used on metal (typically valve balls). It is applied at various thicknesses - 1mm to 3mm with the greater the thickness the better the resiliancy of the coating; 3mm is the preferred thickness in the valve industry. The coating is used as an inexpensive alternative to stainless due to its similar mechanical/chemical properties. The coating is applied to less expensive metals which can significantly reduce cost. Electroless nickel is uniformly deposited on application making it simpler to apply on complex components as opposed to other hard wearing coatings.

A copy of the ASTM B733 spec can be purchased here http://www.astm.org/Standards/B733.htm

Heat treatments - Heat treating is a group of processes used to alter the physical/chemical property of a metal. The four common types of heat treatment in valve materials are:

A - Anneal - This is a general term in which metal is heated to a specific temperature then cooled at a controlled rate that results in a refined micro structure. It is usually used to soften the metal to improve machinability or increase electrical conductivity.

N - Normalize - Normalizing is a technique used to provide consistency in grain size throughout an alloy. Typically it is applied to ferrous alloys that are heated above their critical temperature and allowed to cool in open air.

NT - Normalize and Temper - Temper is an additional step used on martenistic steel making it less brittle. Tempering is typically done by heating the metal to temperatures below the critical temperature to increase toughness.

QT - Quench and Temper - Quenching is a heat treatment in which the metal is heated to a specific temperature then cooled quickly to increase hardening.

For more information on heat treatments visit http://en.wikipedia.org/wiki/Heat_treating


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Valve Tip:
Check valves have a "cracking pressure" or a minimum upstream pressure at which the valve will operate.