Materials and Standards for Valves

Mar 07, 2022
What are WCB, LCB, LCC, WC6 and WC?
W means casting and C carbon steel; A, B and C indicate the strength value of steel grade from low to high. WCA, WCB, WCC represent carbon steel. ABC represents the strength level, and WCB is commonly used. The pipe material corresponding to WCB is A106B, and the corresponding forging material is A105. WC6 is a casting of alloy steel. The corresponding pipe material is A355 P11, and the corresponding forging is A182 F11. In addition, WC9 is high-temperature resistant alloy steel. WC is the weldable casting. LCB or LCC (ASTM A352) is low-temperature carbon steel.
 
Comon carbon steel castings and forgings used for valves
Countries Standards Grades
USA ASTM A216/A216M WCA WCB WCC
UNS J02502 UNS J03002 UNS J02503
USA ASTM A105/A105M A105
 
Grades and applicable temperatures of low-temperature steel casting  
Types C C C-Mn C-Mo 2.5Ni Ni-Cr-Mo 3.5Ni 4.5Ni 9Ni Cr-Ni-Mo
Grades LCA LCB LCC LC1 LC2 LC2-1 LC3 LC4 LC9 CA6NM
UNS numbers J02504 J03303 J02505 J12522 J22500 J42215 J31550 J41500 J31300 J91540
Applicable temperatures ℃ -32 -46 -46 -59 -73 -73 -101 -115 -196 -73
 
Commonly used ASTM materials for valves and castings (ASME B16.5)
ASTM castings ASTM forgings Applicable temperatures ℃ Applicable media
Carbon steel
A216 WCB A105 -29 to 427 Water, steam, air, petroleum products, etc.
Low-temperature carbon steel
A352 LCB A350 LF2 -46 to 343 Low-temperature media
A352 LCC A350 LF2 -46 to 343 Low-temperature media
High-temperature alloy steel
A217 WC1 A182 F1 -29 to 454 High-temperature and high-pressure media
A217 WC6 A182 F11 -29 to 552 High-temperature and high-pressure media
A217 WC9 A182 F22 -29 to 593 High-temperature and high-pressure media
A217 C5 A182 F5 -29 to 650 Corrosive high-temperature media
 
A217 C12 A182 F9 Cr9Mo1 -29 to 593 Media containing high sulfur oxidizing
Martensitic stainless steel
A217 CA15 A182 F6a 1Cr13 -29 to 371 Lower strength than 304 at a temperature of 450℃
Austenitic stainless steel (C being less than and equal to 0.08)
A351 CF8 A182 F304 0Cr18Ni9 -196 to 537 Corrosive media
A351 CF3 A182 F304L   -196 to 425 Corrosive media
A351 CF8M A182 F316 0Cr18Ni12Mo2Ti -196 to 537 Corrosive media
A351 CF3M A182 F316L   -196 to 425 Corrosive media
Ultra-low carbon austenitic stainless steel (C being less than and equal to 0.03)
A351 CF3 A182 F304L 00Cr18Ni10 -196 to 427 Corrosive media
A351 CF3M A182 F316L 00Cr18Ni14Mo2 -196 to 454 Corrosive media
Special alloys
A351 CN7M B462 Gr. NO8020
(ALLOY 20)
  -29 to 149 Oxidizing media and sulfuric acid with various concentrations
A494 M-30C
(Monel)
B564 Gr. NO4400   -29 to 482 Hydrofluoric acid and seawater
Hastelloy H.B H.C       Strong corrosive media such as dilute sulfuric acid
 
Please note that the material of the forged valve body is dense, not easy to be defective; the structure size is not limited by the mold, and the pressure bearing performance is reliable. It is mostly used for manufacturing valves with high pressure, oxygen, small diameters or other small batches. Forgings are selected under high temperature, high pressure, low temperature or special media; castings are generally only suitable for medium and low pressure, and are mostly used in the mass production of standardized formed valves. The difference between A351 CF3M and A182 F316L: The material corresponding to the two standards is 316 stainless steel. CF3M stands for casting and is often used as a valve material. The corresponding forged steel is A182 F316L. ASTM A216 WCB is a casting, and its forging is A105; the casting of SS304 is A351 CF8, and its forging is A182 F304.
 
The selection of valve materials
There are many materials for manufacturing valve parts, including various grades of ferrous and non-ferrous metals and their alloys, and various non-metallic materials. Materials for making valve parts are selected based on the following factors:
  • The pressure, temperature and characteristics of the working medium
  • The force bearing by the part and its role in the valve's structure
  • Good manufacturability
  • Combining low costs with the above conditions
 
Materials for valve bodies, bonnets and discs
  • Gray cast iron: it is suitable for water, steam, air, gas, oil and other media with nominal pressure PN being less than and equal to 1.0MPa and temperatures between -10℃ and 200℃.
  • Malleable cast iron: it is suitable for water, steam, air and oil with nominal pressure PN being less than and equal to 2.5MPa and temperatures of -30 to 300℃.
  • Ductile iron: it is suitable for media such as water, steam, air and oil with PN being less than and equal to 4.0MPa and temperatures of -30 to 350℃.
  • Carbon steel (WCA, WCB and WCC): it is suitable for nominal pressure PN being less than and equal to 32.0MPa, medium and high pressure valves with working temperatures between -29 to +425℃.
  • Low-temperature carbon steel (LCB): it is applied to ethylene, propylene, liquid natural gas, liquid nitrogen and other media with nominal pressure PN being less than and equal to 6.4Mpa, temperatures greater than and equal to -196℃.
  • Alloy steel (WC6, WC9): it is used for high-temperature and high-pressure valves with non-corrosive media with working temperatures between -29 to 595℃; WC5 and WC9 are suitable for high-temperature and high-pressure valves containing corrosive media with working temperatures between -29 to 650℃.
  • Austenitic stainless steel: it is suitable for valves with corrosive media with operating temperatures between -196 to +600℃.
  • Monel alloys: it is mainly suitable for valves with hydrogen fluoride.
  • Cast copper alloys: It is mainly suitable for valves used in oxygen pipelines whose working temperatures are between -29 and 595℃.
 
Table 1-1 Common materials for valve housings
Materials for valve housings Standards Applicable temperatures/℃ Applicable pressure/MPa Applicable media
Gray cast iron   -15 to 200℃ Less than and equal to 1.6 Water and gas
Black heart malleable cast iron   -15 to 300 Less than and equal to 2.5 Water, seawater, gas and ammonia
Ductile iron   -30 to 350 Less than and equal to 4.0 Water, sea water, gas, air and steam
Carbon Steel (WCA, WCB and WCC) ASTM A216 -29 to 425 Less than and equal to 32.0  ASTM A216 -29 to 425
water, oil and gas
Low-temperature
carbon steel (LCB and LCC)
ASTM A352 -46 to 345 Less than and equal to 32.0 Low temperatures
Alloy steel (WC6 and WC9)
(C5 and C12)
ASTM A217 -29 to 595
-29 to 650
High pressure Non-corrosive media and
corrosive media
Austenitic stainless steel ASTM A351 -196 to 600   Corrosive media
Monel ASTM A494 400   Media containing hydrofluoric acid
Hastelloy ASTM A494 649   Dilute sulfuric acid and other strong corrosive media
Titanium alloys       Various strong corrosive media
Cast copper alloys   -273 to 200   Oxygen and seawater
Plastic and ceramic    to 60 Less than and equal to 1.6 Corrosive media
 
 
Grades Materials Standards Applicable conditions Temperature ranges
WCB Carbon steel ASTM A216 Non-corrosive conditions, including water, oil and gas -29℃ to +425℃
LCB Low-temperature carbon steel ASTM A352 low temperatures -46℃ to +345℃
LC3 3.5% nickel steel ASTM A352 low temperatures -101℃ to +340℃
WC6 chromium and 0.5% molybdenum steel ASTM A217 Non-corrosive conditions, including water, oil and gas. -30℃ to +593℃
WC9 2.25 chromium
C5 5% chromium and 0.5% molybdenum ASTM A217 Mildly corrosive, corroded  and non-corrosive applications -30℃ to +649℃
C12 9% chromium and 1%  molybdenum
CA15(4) 12% chromium steel ASTM A217 Corrosive conditions +704℃
CA6NM(4) 12% chromium steel ASTM A487 Corrosive conditions -30℃ to +482℃
CF8M Stainless steel 316 ASTM A351 Corrosive, ultra-low temperature or high-temperature non-corrosive applications The specified carbon content should be 0.04% and above for temperatures between -268°C to +649°C. 
CF8C Stainless steel 347 ASTM A351 High-temperature and corrosive applications The specified carbon content should be 0.04% and above at temperatures between 268°C to +649°C.
CF8 Stainless Steel 304 ASTM A351 Corrosive or ultra-low temperature or high-temperature non-corrosive applications The specified carbon content should be 0.04% and above at temperatures between 268°C to +649°C.
CF3 Stainless Steel 304L ASTM A351 Corrosive or non-corrosive applications +425℃
CF3M Stainless Steel 316L ASTM A351 Corrosive or non-corrosive applications +454℃
CN7M Alloy steel ASTM A351 Having good resistance to hot sulfuric acid corrosion +425℃ +425℃
M35-1 Monel ASTM A494 Having good resistance to all common organic acids, salt water corrosion and good corrosion resistance to most alkaline solutions +400℃
N7M Hastelloy B ASTM A494 It is especially suitable for hydrofluoric acid with various concentrations and temperatures, which has good resistance to sulfuric acid and phosphoric acid corrosion. +649℃
CW6M Hastelloy C ASTM A494 It has good corrosion resistance in strongly oxidizing environments, good properties at high temperatures, good corrosion resistance to formic acid (formic acid), phosphoric acid, sulfurous acid and sulfuric acid. +649℃
CY40 Inconel ASTM A494 It has good performance in high temperatures and good corrosion resistance for highly corrosive fluid media.  
 

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About the author
Teresa
Teresa is a skilled author specializing in industrial technical articles with over eight years of experience. She has a deep understanding of manufacturing processes, material science, and technological advancements. Her work includes detailed analyses, process optimization techniques, and quality control methods that aim to enhance production efficiency and product quality across various industries. Teresa's articles are well-researched, clear, and informative, making complex industrial concepts accessible to professionals and stakeholders.

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