Valve material and valve standards-(2)-body stem bonnet material

Selection of valve material:
There are many materials for manufacturing valve parts, including various types of ferrous and non-ferrous metals and their alloys, and various non-metallic materials. The materials for manufacturing valve parts are selected

according to the following factors:
1. The pressure, temperature and characteristics of the working medium.
2. The force of the part and its function in the valve structure.
3. Have better manufacturability.
4. If the above conditions are met, there must be a lower cost.

Section one: the material of the valve body, bonnet and valve plate
1. Gray cast iron: Gray cast iron is suitable for water, steam, air, gas, oil and other media with a nominal pressure of PN≤1.0MPa and a temperature of -10°C–200°C. The commonly used grades of gray cast iron are: HT200, HT250, HT300, HT500.

2.. Malleable cast iron: suitable for water, steam, air and oil media with a nominal pressure of PN≤2.5Mpa and a temperature of -30-300°C. Commonly used grades are: KTH300-06, KTH330-08, KTH350-10.

3. Nodular cast iron: suitable for water, steam, air and oil with PN≤4.0Mpa and temperature of -30-350°C. Commonly used grades are: QT400-15, QT450-10, QT500-7.

4. Carbon steel (WCA, WCB, WCC): Suitable for nominal pressure PN≤32MPa, suitable for medium and high pressure valves with operating temperature between -29°C and +425°C. Among them, 16Mn and 30Mn work at -29-595°C, and are often used to replace ASTM A105. Commonly used grades are WC1, WCB, ZG25 and high-quality steel 20, 25, 30 and low-alloy structural steel 16Mn.

5. Low temperature carbon steel (LCB): suitable for ethylene, propylene, liquid natural gas, liquid nitrogen and other media with nominal pressure PN≤6.4MPa and temperature ≥-196°C. Commonly used grades are ZG1Cr18Ni9, 0Cr18Ni9, 1Cr18Ni9Ti, ZG0Cr18Ni9.

6. Alloy steel (WC6, WC9), suitable for high temperature and high pressure valves with non-corrosive medium working temperature between -29-595°C; WC5, WC9 are suitable for working temperature between -29-659°C High temperature and high pressure valves for corrosive media.

7. Austenitic stainless steel, suitable for valves with corrosive media with working temperature between -196-600°C.
Eight. Monel alloy: mainly suitable for valves with hydrofluoric medium.
nine. Cast copper alloy: Mainly suitable for valves for oxygen pipelines whose operating temperature is between -29 and 595°C

Fig.1-1 Commonly used valve body material:

valve body material	standard	temp	PN/Mpa	medium
Grey cast Iron		-15/200	≤1.6	water,gas
Black Heart Malleable Cast Iron		-15/300	≤2.5	water, seawater, gas, Ammonia
ductile cast iron		-30/350	≤4.0	water,seawater,gas,air,steam
carbon steel (WCA,WCB,WCC)	ASTM A216	-29/425	≤32	non-corrosive water, oil, gas
Low temp carbon steel (LCB,LCC)	ASTM A352	-46/345	≤32	low temp application
Alloy（WC6，WC9，C5，C12）	ASTM A217	-29/595 -29/650	High pressure	non-corrosive corrosive medium
Austenitic stainless steel	ASTM A351	-196/600		corrosive medium
Monel alloy	ASTM A494	400		Hydrofluoric acid medium
Hastelloy	ASTM A494	649		Strong corrosive medium such as dilute sulfuric acid
Titanium alloy				Various strong corrosive media
Cast copper alloy		-273/200		Oxygen, sea water
Plastic, Ceramic		-60	≤1.6	corrosive medium

 

Name	material	standard	temp range °C	application
WCB	carbon steel	ASTM A216	-29/425	non-corrosive water, oil and gas
LCB	low temp carbon steel	ASTM A352	-46/345	low temp applicaion
LC3	3.5% nickel steel	ASTM A352	-101/340	low temp applicaion
WC6	1.25% chromium,         0.5% molybdenum	ASTM A217	-30/593	non-corrosive water, oil and gas
WC9	2.25% chromium
C5	5% chromium,0.5% molybdenum	ASTM A217	-30/649	light or non-corrosive application
C12	9% chromium 1% molybdenum
CA15(4)	12% chromium	ASTM A217	704	corrosive application
CA6NM(4)	12% chromium	ASTM A487	-30/482	corrosive application
CF8M	stainless steel 316	ASTM A351	-268/649 when <425, need C=0.04% info	corrosive,ultra low/high temp with no corrosive application
CF8C	stainless steel 347	ASTM A351	-268/649 when <425, need C=0.04% info	high temp, corrosive application
CF8	stainless steel 304	ASTM A351	-268/649 when <425, need C=0.04% info	corrosive,ultra low/high temp with no corrosive application
CF3	stainless steel 304L	ASTM A351	425	corrosive or non-corrosive
CF3M	stainless steel 316L	ASTM A351	454	corrosive or non-corrosive
CN7M	alloy	ASTM A351	425	Good resistance to hot sulfuric acid corrosion
M35-1	monel	ASTM A494	400	Weldable grade, good resistance to common organic acid and salt water corrosion, resistance to most alkaline solutions
N7M	Hastelloy B	ASTM A494	649	Suitable for treating various concentrations and temperatures of hydrofluoric acid, with good resistance to corrosion by sulfuric acid and phosphoric acid
CW6M	Hastelloy C	ASTM A494	649	Very good resistance to strong oxidation, resistance to phosphoric acid, sulfurous acid and sulfuric acid at high temperatures
CY40	Inconel alloy	ASTM A494		Resistant to strong corrosive fluids at high temperatures

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

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