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
USA	ASTM A216/A216M	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	ASTM A217	Non-corrosive conditions, including water, oil and gas.	-30℃ to +593℃
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	ASTM A217	Mildly corrosive, corroded and non-corrosive applications	-30℃ to +649℃
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.