valve material Archives

Introduction to Common Butterfly Valve Materials

January 14, 2022

This article makes an introduction to the commonly used butterfly valve materials. For butterfly valves, you should already have a certain understanding. There are many types of butterfly valves. According to the different connection forms, they can be divided into wafer butterfly valves and flanged butterfly valves; according to different sealing surface materials, they can be divided into soft sealing butterfly valves and metal hard sealing. Butterfly valve;

Types of wafer butterfly valves

according to the different driving methods, it can be divided into handle butterfly valve, turbine butterfly valve, pneumatic butterfly valve, electric butterfly valve and so on. So what are the commonly used butterfly valve materials?
Commonly used butterfly valve materials are mainly cast iron, cast steel, stainless steel three categories. Each material can be further subdivided. Below we will give an introduction to these three types of butterfly valve materials.

Category 1: Cast Iron
Cast iron is subdivided into four categories: gray cast iron, malleable cast iron, ductile iron, and nickel cast iron. This article mainly introduces the two main cast iron materials made by Tanghai valve: gray cast iron, ductile iron and stainless steel.

lug butterfly valve-lined-PTFE-DI body (1)

Gray cast iron is cast iron with flake graphite, because the fracture is dark gray when broken, so it is called gray cast iron. Gray cast iron is the most widely used cast iron, and its output accounts for more than 80% of the total output of cast iron. The casting performance, cutting performance and wear resistance of gray cast iron are very good. Its disadvantage is that its strength, plasticity and toughness are lower than other cast irons.
Grey cast iron is used as the material of butterfly valve, which is usually suitable for weak acid and weak alkali media such as water and air, but not suitable for pipelines with perhydrochloric acid and nitric acid media.
Ductile iron is a high-strength cast iron material with very high strength, toughness and wear resistance, and its comprehensive performance is close to that of steel. At present, the application range of ductile iron is second only to gray cast iron. We often say “replace steel with iron”, which refers to ductile iron.

U type flange butterfly valve (4)

Ductile iron is used as the material of butterfly valve, which has certain corrosion resistance and performance is much higher than that of butterfly valve made of gray iron. The applicable medium includes steam, general gas and oil.

The second category: cast steel
Cast steel is a cast iron alloy, which is a general term for iron-based alloys used to produce castings that do not undergo eutectic transformation during solidification. The advantages of cast steel are greater design flexibility and variability, increased overall structural strength and a wide range of weight variations. Using cast steel as the butterfly valve material, the performance is better than that of cast iron but not as good as stainless steel. Butterfly valve made of cast steel is suitable for steam, non-corrosive gas, oil, etc.

The third category: stainless steel
Stainless steel refers to steel that is resistant to weak corrosive media such as air, steam, and water, and chemically corrosive media such as acid, alkali, and salt, also known as stainless acid-resistant steel. Generally, the butterfly valve made of stainless steel has the best performance and can be used in more severe working conditions. It is used in some ultra-high temperature, ultra-low temperature and strong acid-base corrosive medium pipelines. Wear-resistant and long-lasting.

The above is the introduction of commonly used butterfly valve materials. Generally speaking, the price of stainless steel butterfly valve is the highest, and gray cast iron is the cheapest. If you want to know more about butterfly valve, you are welcome to visit Tanghai Valve”

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

Video of center-lined butterfly valve:

Valve material comparison table-valve pressure-temperature

October 27, 2020

The relationship between valve temperature and pressure:
The valve operating temperature and pressure have a certain internal connection and influence each other. Among them, temperature is the dominant factor affecting the valve. A valve with a certain pressure is only suitable for a

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

certain temperature range, and changes in valve temperature can affect the valve’s operating pressure. E.g:
The nominal pressure of a carbon steel valve is 10MPa. When the medium working temperature is 200℃, its maximum working pressure P20 is 10MPa; when the medium working temperature is 400℃, its maximum working pressure P40 is 5.4MPa; when the medium works When the temperature is 450℃, the maximum working pressure P20 is 4.5MPa.

Valve material temperature and pressure comparison table:
Valve material and applicable pressure, temperature and grade
Gray cast iron is suitable for water, steam, air, gas, oil and other media with nominal pressure PN≤1.0MPa and temperature -10℃～200℃. Commonly used grades are: HT200, HT250, HT300, HT350.
Malleable cast iron Suitable for water, steam, air and oil media with nominal pressure PN≤2.5MPa and temperature -30～300℃. Commonly used grades are: KTH300-06, KTH330-08, KTH350-10.
Nodular cast iron is suitable for water, steam, air and oil with PN≤4.0MPa and temperature of -30～350℃. Commonly used grades are: QT400-15, QT450-10, QT500-7. At present, the level of domestic technology varies among factories, and it is often difficult for users to inspect. It is recommended that PN≤2.5MPa, and steel valves are used for safety.
Acid-resistant high-silica ductile iron Suitable for nominal pressure PN≤0.25MPa, suitable for corrosive media with temperature lower than 120℃.
Carbon steel is suitable for water, steam, air, hydrogen, ammonia, nitrogen and petroleum products with a nominal pressure of PN≤32.0MPa and a temperature of -30～425℃. Commonly used grades are WC1, WCB, ZG25, high-quality steel 20, 25, 30 and low-alloy structural steel 16Mn.
Copper alloy is suitable for water, sea water, oxygen, air, oil and other media with PN≤2.5MPa and steam media with temperature of -40～250℃. Commonly used grades are ZGnSn10Zn2 (tin bronze), H62, Hpb59-1 (brass) , QAZ19-2, QA19-4 (aluminum bronze).
High-temperature copper is suitable for steam and petroleum products with nominal pressure PN≤17.0MPA and temperature≤570℃. The specific selection must be in accordance with the valve pressure and temperature specifications. Commonly used grades are ZGCr5Mo, 1Cr5M0.ZG20CrMoV, ZG15Gr1Mo1V, 12CrMoV, WC6, WC9, etc.
Low-temperature steel is suitable for media with nominal pressure PN≤6.4Mpa and temperature≥-196℃ ethylene, propylene, liquid natural gas, liquid nitrogen, etc. Commonly used grades are ZG1Cr18Ni9, 0Cr18Ni9, 1Cr18Ni9Ti, ZG0Cr18Ni9
Stainless and acid-resistant steel Suitable for media such as nitric acid and acetic acid with nominal pressure PN≤6.4Mpa and temperature≤200℃. Commonly used grades are ZG0Cr18Ni9Ti, ZG0Cr18Ni10<nitric acid>, ZG0Cr18Ni12Mo2Ti, ZG1Cr18Ni12Mo2Ti<acid and urea>

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

Valve material and valve standards-(9)- general valve & parts materials

September 9, 2020

General valve material
The internal material combination specified by API600 for general valve material:

Stem material types	hardness	sealing surface
Stem material types	hardness	seal part no.,	material type	hardness
13Cr	200-275	1	13Cr	≥HB250
		4	13Cr	≥HB750
		5 or 5A	HF	≥HB350
		6	13Cr/NiCu	≥HB750/≥HB175
		7	13Cr/13Cr	≥HB250/≥HB750
		8-8A	13Cr/HF	≥HB250/≥HB350
18Cr-8Ni	no require	2	18Cr-8Ni	no require
25Cr-20Ni		3	25Cr-20Ni
Nickel copper alloy		9	Nickel copper alloy
Nickel copper alloy		11 or 11A	Nickel copper alloy/HF	no require/≥HB350
18Cr-8Ni-Mo		10	18Cr-8Ni-Mo	no require
18Cr-8Ni-Mo		12 or 12A	18Cr-8Ni-Mo/HF	no require/≥HB350
19Cr-29Ni		13	19Cr-29Ni/HF	no require
19Cr-29Ni		14 or 14A	19Cr-29Ni/HF	no require/≥HB350

Commonly used valve trim material combination:

valve stem	sealing surface	valve stem	sealing surface
13Cr	13Cr/13Cr	321	321/321
13Cr	13Cr/STL	321	321/STL
13Cr	STL/STL	321	STL/STL
13Cr	13ZCr/Monel	1Cr18Ni9Ti	1Cr18Ni9Ti/1Cr18Ni9Ti
17-4PH	STL/STL	1Cr18Ni9Ti	1Cr18Ni9Ti/STL
17-4PH	17-4PH/17-4PH	1Cr18Ni9Ti	STL/STL
Monel	Monel/Monel	1Cr18Ni12Mo2Ti	1Cr18Ni12Mo2Ti/1Cr18Ni12Mo2Ti
304	304/304	1Cr18Ni12Mo2Ti	1Cr18Ni12Mo2Ti/STL
304	304/STL	1Cr18Ni12Mo2Ti	STL/STL
304	STL/STL	20 Alloy	20alloy/20alloy
316	316/316	Hastelloy B	Hastelloy B/Hastelloy B
316	316/STL	Hastelloy C	Hastelloy C/Hastelloy C
316	STL/STL	F51	F51/F51
304L	304L/304L	F51	F51/STL
304L	304L/STL	38CrMoALA	STL/STL
304L	STL/STL	25Cr2MoIV A	STL/STL
316L	316L/316L	4Cr10Si2Mo	STL/STL
316L	316L/STL	4Cr14Ni14W2Mo	STL/STL
316L	STL/STL	Inconel	Inconel/Inconel

Commonly used fastener material:

Bolts	Nuts	Max temp °C
35	25	425
35CrMo	35, 45	425
35CrMo	30CrMo	500
25Cr2MoVA	30CrMo	550
0Cr18Ni9	0Cr18Ni9	600
0Cr17Ni12Mo2	0Cr17Ni12Mo2	600
25Cr2Mo1VA	25Cr2Mo1VA	600
25Cr2MoVA	25Cr2MoVA	600

Matching materials of bolts and nuts for American standard valves:

Bolts		nuts		application temp
standard	grade name	standard	grade name	application temp
ASTM A193	B7	ASTM A194	2H	-29/425°C
	B7M		2HM	-29/425°C NACE standard, anti-sulfer valve
	B16		7	-29/593°C
	B8		8	-196/700°C
	B8M		8M	-196/700°C
ASTM A320	L7		4	-46/101°C Cryogenic valve

Chemical composition and mechanical properties of commonly used bolts and nuts for American standard valves:

Chemical composition and mechanical properties of commonly used bolts and nuts for American standard valves

Conditions of use of metal gaskets:

material	HB max	Pressure Mpa(lb)	suitable temp °C
10/08	120	2.0-42(150-2500)	450
0Cr13	170	2.0-15(150-900)	540
0Cr18Ni9	160		600
0Cr17Ni12Mo2	160		600

Spiral wound gasket service conditions:

metal belt material	Non-metallic belt material	Pressure grade Mpa (lb)	suitable temp °C
0Cr18Ni9	flexible graphite	2.0-26(150-1500)	650
0Cr17Ni12Mo2	flexible graphite		650
00Cr17Ni14Mo2	PTFE		200

Conditions for use of metal-clad gasket:

Cladding metal material	HB	filling material	pressure Mpa(lb)	suitable temp °C
Al L3	40	asbestos	2.0-15(150-900)	200
Co T3	60			300
Galvanized steel sheet	90			400
Galvanized steel sheet 08F	90			400
0Cr18Ni9	187			500
00Cr19Ni10
00Cr17Ni14Mo2

Use conditions of flexible graphite composite gasket:

Core board and edging material	pressure grade Mpa (lb)	suitable temp °C
low-carbon steel	2.0-11(150-600)	450
0Cr18Ni9	2.0-11(150-600)	650

Non-metallic gasket usage conditions:

material name	code name	pressure Mpa	suitable temperature °C
natural rubber	NR	2.0	-50/90
Neoprene	CR	2.0	-40/100
NBR	NBR	2.0	-30/110
Ethylbenzene rubber	SBR	2.0	-30/110
EPDM rubber	EPDM	2.0	-40/130
fluororubber	Viton	2.0	-50/200
Asbestos Rubber Sheet	XB350 XB450 NY400	2.0 ≤300 P.T≤650 Mpa °C
Oil-resistant asbestos rubber sheet	XB350 XB450 NY400	2.0 ≤300 P.T≤650 Mpa °C
Modified or filled with PTFE		5.0	-196/260

Comparison table of common metal materials specified by Chinese, Japanese, German, British, American and international standards:

Comparison table of common metal materials specified by Chinese, Japanese, German, British, American and international standards

WC carbon steel +A/B/C –WCA,WCB,WCC

WC carbon steel +ABC –WCA,WCB,WCC

Please see the Full documentation at this link: https://www.tanghaivalve.com/wp-content/uploads/2020/09/valve-material-and-valve-standards-Detailed-version.pdf

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

Valve material and valve standards-(8)- Monel alloy application

September 7, 2020

4. Application of Monel alloy:
The A and E levels of M35-1, M35-2 and QQ-N2-88 are usually used to manufacture refined Monel alloy pumps,

buttefly valve stem shaft parts (6)

valves and accessories. The B-grade (3.5%Si) Monel alloy with the highest Si content is mainly used to manufacture shafts and wear-resistant rings that require good wear resistance due to its high strength, corrosion resistance and wear resistance. Class D (4.0% Si) Monel alloy is used to manufacture parts that require higher wear resistance and corrosion resistance.
Monel alloy valves have two types: integral and internal. The integral Monel alloy valve means that the valve shell and internal parts are all Monel, which is mainly used in the HF acid regeneration tower part of the alkylation unit of the refinery. Due to the high HF acid regeneration temperature (149°C) and high water content, an overall alloy valve is required. In addition, the overall Monel alloy valve is also used in the production of ashless additives for catalysts in refineries and high-concentration chlor-alkali systems in chlor-alkali plants. Situation.
The Monel alloy internal valve means that the valve housing is made of carbon steel or stainless steel, and the internal valve is made of Moenl alloy. The Monel alloy valve with carbon steel as the shell is mainly used in the low temperature area of the HF calculation system of the alkylation unit of the refinery. The use of carbon steel is good for low temperature (≤71°C) anhydrous hydrofluoric acid (HF) However, carbon steel will form a film on its surface due to corrosion when used in this working condition for a long time. If carbon steel is used in the valve sealing part, the film formed after corrosion will affect the sealing performance of the valve. It should be pointed out that the commonly used Cr13 type sealing material for carbon steel valves cannot resist the corrosion of HF acid, and the internal material is much cheaper for Monel alloy valves. The Monel alloy valve with carbon steel as the shell can also be used in working conditions such as sea water. The valve housing is made of stainless steel Monel alloy internal valve, which is used in ethylene, propylene, liquid oxygen, pure oxygen, sea water and other working conditions. The monolithic Monel alloy valve and Monel alloy internal valve used in the alkylation unit require a pressure level of CL300 from a safety point of view. The pressure level of Monel alloy internal valve for other working conditions is CL150 and CL300. Or PN116-614Mpa etc.
5. Melting and casting of monel alloy:
The smelting and casting technology of Monel alloy is the key to determine whether the qualified Monel alloy castings can be produced. Because Moenl alloy has developed dendrites, shrinkage cavities and porosity, the tendency of gas absorption (hydrogen absorption, oxygen absorption) is great, and it will Sulfurizing chemical reaction occurs with molding materials. From a safety point of view, Monel alloy valves are required to undergo radiographic inspection in accordance with Class A pipeline valves in highly toxic and dangerous media such as hydrofluoric acid, chlorine and hydrogen chloride gas. . Although the American standard points out that casting M35-1 can be welded, in fact its weldability is extremely poor, and the quality of repaired castings is difficult to guarantee. The density of M35-1 alloy is 8163t/m3 (at 20°C), the solidification shrinkage rate is 21mm/m, and the alloy melting point is 1315-1345°C. The Class A and Class E of M35-1, M35-2 and QQ-N2-88 are delivered as cast. Although there are many grades of cast Monel alloy, when used to cast Monel alloy valve castings, M35-1 in ASTMA494 is mainly used.
Cast Monel alloy and deformed Monel alloy have little change in chemical composition (Table 4), but this change satisfies its better deformability for deformation and gold, while it provides better casting for cast alloys. performance. This is the reason why cast Monel alloy grades are used when casting, and deformed Monel alloy grades are used when selecting rolling materials.
Table 4. Commonly used cast and deformed Monel alloy chemical composition of valves (%)

Grade name	chemical composition /%
Grade name	C	Mn	Si	P	S	Cu	Fe	Ni	others
M35-1	≤0.35	≤1.5	≤1.25	≤0.03	≤0.03	26-33	≤3.5	Ba
Monel400	≤0.30	≤2.0	≤0.5		≤0.024	Ba	≤2.5	63-70
MonelK500	≤0.25	≤1.5	≤0.5		≤0.01	Ba	≤2.0	63-70	Al2.5-3.5, Ti0.35-0.85

6. Conclusion
The current U.S. technical standards for Monel alloys include ASTM, SAE, AMS (American Aeronautical Standards Institute), MIL (U.S. Department of Defense Standards), ANSI, ASME and QQ (American Federal Standards). For the Monel alloy of the same grade, different technical specification systems are adopted, not only the representation method of the grade is different, but the number and content of the specification are not completely the same. Usually military products use MIL, QQ or AMS specifications, and civil products use ASTM and ASME specifications.

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.

Valve material and valve standards-(7)- Monel alloy

September 7, 2020

Monel alloy for corrosion resistant valve
1. Introduction/overview of Monel alloy:
Monel alloy, cast nickel alloy, Hastelloy alloy, etc. are all materials for making special purpose valves. Monel alloy is a Ni-Cu alloy in nickel-based corrosion-resistant alloys. It was first developed by the US Nickel Company. Its typical composition is 70% Ni and 30% Cu. It is the most widely used nickel-based corrosion-resistant alloy.

Monel alloy not only has high strength and toughness, but also has excellent resistance to corrosion by reducing acid and strong alkali media and sea water, so it is usually used to manufacture and transport hydrofluoric acid (HF), salt water, neutral media, and alkali salts. And reducing acid medium equipment. Monel alloy is also suitable for dry chlorine, hydrogen chloride, high temperature chlorine (425°C) and high temperature hydrogen chloride and other media, but it is not resistant to corrosion by sulfur-containing media and oxidizing media (such as nitric acid, media with high oxygen content), and it is nickel It reacts violently with sulfur and oxygen and easily forms Ni3S2 and NiO.

2. Performance of Monel alloy:
Monel alloy is a Ni-Cu solid solution, where Cu is used as a non-oxidizing resist added to Ni, which improves the corrosion resistance of nickel alloys and acts as a strengthening alloy. The addition of C can improve the casting performance of the alloy, but only 0.15% of C can be dissolved in the alloy at room temperature, and the excess C will be precipitated as a graphite phase. Adding 1.5%-3.5% Fe can also improve the casting performance of the alloy. Adding Mn and Si can improve the mechanical properties of the alloy, especially the content of Si has an important influence on the mechanical and physical properties of the Monel alloy.

3. Classification of Monel alloy:
Monel alloys are classified into casting alloys and deformed alloys.
3.1 Deformation alloy: There are more than 10 types of deformed Monel alloys in the United States, such as Monel400, MonelC, Monel403, Monel404, Monel R2405, Monel406, Monel411, MonelK500, MonelK501 and Monel502. Because Monel has its own representation methods in different American standard systems, SAE and ASTM jointly developed ASTM2SAE unified digital system (unified numbt system2 UNS) in order to facilitate the use and unified management of calculations. In the United States’ UNS, nickel alloys have 5 grades of deformed Monel alloys, including solid solution hardened No5500 (Monel400), No4404 (Monel404) and No4405 (MonelR2405), and precipitation hardened NO5500 (MonelK500) and NO5502 (Monel502). ) Etc. (refer to Table 1). Among them, the deformed Monel alloy commonly used in the manufacture of corrosion-resistant valves is Monel400 and MonelK500.
Table 1. Chemical composition of deformed Monel alloy in United States UNS

Grade name	chemical composition/ %
Grade name	C	Si	Mn	S	Ni	Fe	others
NO4400(Monel400)	≤0.3	≤0.5	2	≤0.024	63-70	≤2.5	Cu base
No4404(Monel404)	≤0.15	≤0.1	≤0.1	≤0.024	52-57	≤0.5	Cu base, Al≤0.05
No4405(MonelR2405)	≤0.3	≤0.5	≤2.0	0.025-0.06	63-70	≤2.5	Cu base
No5500(MonelK500)	≤0.25	≤0.5	≤1.5	≤0.01	63-70	≤2	Cu base, Al213-3115,Ti0135-0185
NO5502(Monel502)	≤0.10	≤0.5	≤1.5	≤0.01	63-70	≤2	Cu base, Al215-315

3.2 Casting alloy: The American cast Monel alloy has five grades of M35-1, M35-2, M-30H, M-25S and M-30C in ASTM A494 (Table 2), which is in the US Federal Standard QQ-N2-88 There are also 5 cast Monel alloys (Table 3).
Table 2. Cast Monel alloy in ASTM A494:

grade name

chemical composition /%

mechanical properties

C

Mn

Si

P.S

Cu

Fe

Ni

Nb

Compressive strength/Mpa

Tensile strength/Mpa

Elongation rate/%

HB

M35-1(a)

≤0.35

≤1.5

≤1.25

≤0.03

26-33

≤3.5

Ba

≥450

≥170

≥25

M35-2

≤0.35

≤1.5

≤2.00

≤0.03

26-33

≤3.5

Ba

≥450

≥205

≥25

M-30H

≤0.30

≤1.5

2.7-3.7

≤0.03

27-33

≤3.5

Ba

≥690

≥415

≥10

M-25S

≤0.25

≤1.5

3.5-4.5

≤0.03

27-33

≤3.5

Ba

243-294(b)

M-30C(a)

≤0.30

≤1.5

1.0-2.0

≤0.03

26-33

≤3.5

Ba

1-3

≥450

≥225

≥25

125-130(b)

Notes:
1.Ba=balance, means the balance is all Ni content.
2. To remove the weldability, it should be M3521 or M230C
3. This table is a data parameter
4. HB minimum is 300
Table 3 QQ2N2288 cast Monel alloy:

QQ-N-288	chemical composition /%							mechanical properties
QQ-N-288	C	Si	Mn	Cu	Fe	Ni	Nb	Compressive strength/Mpa	Tensile strength/Mpa	Elongation rate/%	HB
A	≤0.35	≤2.0	≤1.5	26-33	≤2.5	62-68		≥448	≥224	≥25	125-150
B	≤0.30	2.7-3.7	≤1.5	27-33	≤2.5	61-68		≥689	≥455	≥10	240-290
C	≤0.20	3.3-4.5	≤1.5	27-31	≤2.5	≥60		≥825	≥550	≥10	250-300
D	≤0.25	3.5-4.5	≤1.5	27-31	≤2.5	≥60					≥300
E	≤0.30	1.0-2.0	≤1.5	26-33	≤2.5	≥60	1-3	≥448	≥221	≥25	125-150

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.

Valve material and valve standards-(6)-gasket material

September 3, 2020

Valve Gasket material:
The gasket is used to fill all the unevenness between the two joint surfaces (such as the sealing surface between the valve body and the bonnet) to prevent the medium from leaking between the joint surfaces.

lug type butterfly valve, ductile iron, center lined,

1. Requirements for gaskets: The gasket material has a certain degree of elasticity, plasticity and sufficient strength at working temperature to ensure sealing. At the same time, it must have good corrosion resistance.

2. Types and selection of gasket materials: gaskets are divided into two types: soft and hard. The soft is generally non-metallic materials, such as cardboard, rubber, asbestos rubber sheet, and PTFE. Hardness is generally metal material or metal-coated asbestos, metal and asbestos entangled, etc.

There are many forms of gaskets, including flat, round, oval, tooth-shaped, lens-shaped and other special shapes.
Metal gaskets are generally made of 08, 10, 20 high-quality carbon steel and 1Cr13, 1Cr18Ni9 stainless steel, which require high machining accuracy and surface finish, and are suitable for high temperature and high pressure valves.
Non-metallic gasket materials generally have good plasticity and can be sealed with less pressure, which is suitable for low temperature and low pressure valves.
The gasket material can be selected according to Table 5-4.

Gasket material	medium	Pressure/Mpa	Temp/°C
cardboard	water, oil	≤10	40
Oil-impregnated cardboard	water, oil	≤10	40
rubber board	water,air	≤6	50
asbestos board	steam, gas	≤6	450
PTFE	corrosive	≤25	200
rubber asbestos board XB-450	water steam, air, gas	≤60	450
XB-350	water steam, air, gas	≤40	350
XB-250	water steam, air, gas	≤15	200
Oil-resistant rubber asbestos sheet	oil	160	30
08 steel and XB-450 filling	steam	100	450
08 steel and XB-350 filling	steam	40	350
1Cr13,0Cr13 and asbestos filling	steam	100	600
08 steel and oil-resistant rubber and asbestos filling	oil	100	350
copper	water steam,air	100	250
aluminium	water steam,air	64	350
10steel, 20steel	water steam, oil	2–	450
1Cr13	steam	200	550
1Cr3Ni9	steam	200	600

Attached Table 1-2 Common Materials for Valve Trim:

internal parts material	suitable temp/°C	internal parts material	suitable temp/°C
304	-268/316	SS440 60RC	-29/427
316	-268/316	17-4PH	-40/427
bronze	-273/232	6 alloy(Co-Cr)	-273/816
inconel alloy	-240/649	Electroless Nickel	-268/427
K monel alloy	-240/482	chrome	-273/316
monel alloy	-240/482	NBR	-40/93
hastelloy B	-198/371	Viton	-23/204
hastelloy C	-198/538	PTFE	200
Titanium alloy	-29/316	Nylon	-73/93
Nickel alloy	-198/316	Polyethylene	-73/93
20 alloy	-46/316	Neoprene	-40/82
SS416 40RC	-29/427

Attached Table 1-3 Common materials and operating temperature of valve sealing surface:

Sealing surface material	temp range / °C	hardness	suitable medium
bronze	-273/232		water, seawater, air,oxygen,saturated vapor
316L	-268/316	14HRC	Slightly corrosive and non-impact media like steam, water, oil, gas,liquid gas
17-4PH	-40/400	40-50HRC	slightly corrosive and impact medium
Cr13	-101/400	37-42HRC	slightly corrosive and impact medium
Stellite alloy	-268/650	40-45HRC (normal temp); 38HRC (650°C)	impact and corrosive medium
Monel alloy KS	-240/482	27-35HRC, 30-38HRC	Air-free acid solution like alkali, salt,food
Hastelloy CB	371, 538	14HRC, 23HRC	Corrosive mineral acid, sulfuric acid, phosphoric acid, wet hydrochloric acid gas, chlorine-free acid solution, strong oxidizing medium
20 alloy	-45.6/316	36-61HRC	Oxidizing medium and various concentrations of sulfuric acid

Material table of stem, sealing surface, gasket, packing and fastener of cast iron valve:

name	standard	material name	remarks
Vlave stem	ASTM A182	F6a
	ASTM A276	410,420
	GB/T 1220	1Cr13, 2Cr13
sealing surface	GB/T 1176	ZCuZn25A15Fe3Mn3	Cast aluminum brass
		ZCuZn38Mn2Pb2	Cast manganese brass
		ZCuS19Mn2, ZCuAl10Fe3	cast aluminum bronze
	GB/T 1220	1Cr13,2Cr13,1Cr18Ni9,1Cr18Ni9Ti
		PTFE
		rubber
gasket	GB/T 3985	XB350,XB450	rubber asbesto sheet
		1Cr13/XB450	Spiral wound gasket
	GB/T 3985	1Cr18Ni9/XB450	Spiral wound gasket
filler		PTFE
filler	JB/T 6617	flexible graphite ring
fastener	GB/T 699	bolt 35/nut25
fastener	GB/T 3077, GB/T 699	bolt 30CrMo, 35CrMo/nut 35,45

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

Valve material and valve standards-(5)-packing material

September 3, 2020

Packing /Filler material:
On the valve, the packing is used to fill the space of the valve cover packing chamber to prevent the medium from leaking through the valve stem and the bonnet packing chamber.

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

Requirements for packing.

1. Good corrosion resistance, the filler must be able to withstand the corrosion of the medium in contact with the medium.
2. Good airtightness, the packing will not leak under the action of the medium and working temperature.
3. The friction coefficient is small to reduce the friction torque between the valve stem and the packing.

Types of filler:

1. Soft filler: it is a string woven from plant matter, that is hemp, flax, cotton, jute, etc., or mineral, that is, asbestos fiber, or asbestos fiber with metal wire inside and graphite powder coated on the outside. Pressed molding fillers, and flexible graphite filler materials developed in recent years.
Vegetable packing is often used for low pressure valves below 100°C; mineral packing can be used for valves with 450-500°C. In recent years, the temperature of structural media using rubber O-rings as fillers is generally limited to below 60°C.
The packing on the high temperature and high pressure valve is also made of pure asbestos and flake graphite powder.

2. Hard filler: that is, filler made of metal or metal mixed with asbestos and graphite and filler formed by pressing and sintering of PTFE, metal filler is used less.

Selection of filling material:
The choice of packing should be based on the medium, temperature and pressure. The commonly used materials are as follows:

1. Oil-impregnated asbestos rope, can be selected according to Table 5-2
2. Rubber asbestos rope, can be selected according to 5-3
3. Graphite asbestos rope: The asbestos rope is coated with graphite powder, the usable temperature is above 450°C, and the pressure can reach 16MPA, which is generally suitable for high-pressure steam. Lately, it gradually adopts the compressed herringbone type packing, which is placed in a single circle and has good sealing performance.
4. Polytetrafluoroethylene: This is a kind of filler that is currently widely used. Especially suitable for corrosive media, but the temperature should not exceed 200°C. Generally, it is made by pressing or rod car.

Fig.5-2:

Material	Grade name	shape	size(dia or square)	Max Pressure kgf/cm2	max temp/ °C	application
Oil-impregnated asbestos rope	YS450	F	3,4,5,6,8,10,13,16,19,22,25	60	450	water, steam,air,petroleum products
		Y	5,6,8,10,13,16,19,22,25
		N	3,5,6,8,10,13,16,19,22,25
	YS350	F,Y,N	3,5,6,8,10,13,16,19,22,25	45	350
	YS250	F,Y,N	3,5,6,8,10,13,16,19,22,25	45	250

Note: The shape code F means square, through the heart or one or more layers of weaving; Y means round, with a twisted core in the middle and one or more layers of weaving on the outside; N means twisted.

Fig.5-3:

Material	Grade name	size(dia or square)	Max Pressure kgf/cm2	max temp/ °C	application
Rubber, asbestos, packing	XS450	3,4,5,6,8,10,13,16,19,22,25,28	60	450	steam,petroleum products
	XS350		45	350
	XS250		45	250

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

Valve material and valve standards-(4)-fastener material

September 3, 2020

Fastener materials: Fasteners mainly include bolts, studs and nuts. The fastener directly bears the pressure on the

bolts and nuts for butterfly valve

valve, which plays a key role in preventing the outflow of the medium. Therefore, the selected material must ensure sufficient strength and impact toughness at the operating temperature.

When selecting fastener materials according to medium pressure and temperature, the following table can be selected:

Name	Pn(Mpa)	medium temp /°C
		300	350	400	425	450	530
bolt Stud bolt	1.6-2.5	Q235(A3)		35		30CrMoA	–
	4.0-10.0	35				35CrMoA	25Cr2MoVA
	16.0-20.0	30CrMoA		35CrMoA			25Cr2MoVA
nut	1.6-2.5	Q235(A3)		30		35
	4.0-10.0	30				35	35CrMoA
	16.0-20.0	35					35CrMoA

Heat treatment must be carried out when selecting alloy steel materials. When there are special corrosion resistance requirements for fasteners, stainless acid-resistant steels such as Cr17Ni2, 2Cr13, 1Cr18Ni9 can be selected.

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

Valve material and valve standards-(3)-sealing material

August 28, 2020

Section 2: Sealing surface material
The sealing surface is the most critical working surface of the valve. The quality of the sealing surface is related to the service life of the valve. Generally, the sealing surface material considers factors such as corrosion resistance, scratch resistance, erosion resistance, and oxidation resistance. Generally, sealing surface materials are divided into two categories:
1. Soft materials

soft sealing marine valve, rubber sealing, valve seat parts

1. Rubber (including nitrile rubber, ethylene propylene rubber, fluorine rubber, etc.)
2. Plastics (polytetrafluoroethylene, nylon, etc.)
2. Hard sealing material
1. Copper alloy (for low pressure valve)
2. Chrome stainless steel (used for ordinary high and medium pressure valves)
3. Stellite alloy (used for high temperature and high pressure valves and strong corrosion valves)
4. Nickel-based alloy (used for corrosive media)

Section 3: Valve Stem Material
During the opening and closing of the valve, the valve stem bears tensile, compressive and torsional forces, and is in direct contact with the medium. At the same time, there is relative frictional movement with the packing. Therefore, the valve stem material must ensure sufficient strength at the specified temperature And impact toughness, a certain degree of corrosion resistance and abrasion resistance, and good manufacturability. Commonly used valve stem materials are as follows:
1. Carbon steel: For water with low temperature and medium temperature not exceeding 300°C, when steam

18 buttefly-valve-stem-shaft-parts-1

medium, A5 ordinary carbon steel is generally selected (now Q275, A3 is Q235)
2. Alloy steel: For medium pressure and high pressure, when the medium temperature does not exceed 450°C, 40Cr (chromium steel) is generally used when the medium temperature does not exceed 450°C. Water, the medium temperature does not exceed 540°C For steam and other media, 38CrMoAlA nitriding steel can be selected; for high-pressure steam media with a medium temperature not exceeding 570°C, 25Cr2MoVA chromium molybdenum vanadium steel is generally selected.
3. Stainless and acid-resistant steel: used for medium and high pressure, non-corrosive and weakly corrosive media with a medium temperature not exceeding 450°C. 1Cr13, 2Cr13, 3Cr13 chromium stainless steel can be selected; when used in corrosive media, it can be used Use Cr17Ni2, 1Cr18Ni9Ti, Cr18Ni12Mo2Ti, Cr18Ni12Mo3Ti and other stainless acid-resistant steels and PH15-7Mo precipitation hardening steels.
4. Heat-resistant steel: 4Cr10Si2Mo martensitic heat-resistant steel and 4Cr14Ni14W2Mo austenitic heat-resistant steel can be used for high-temperature valves whose medium temperature does not exceed 600°C.

Section 4: Valve Stem Nut Material
The stem nut directly bears the axial force of the stem during the opening and closing of the valve, so it must have a certain strength. At the same time, it and the valve stem are threaded transmission, which requires a small coefficient of friction, no rust and avoid seizure. The main materials are as follows:
1. Copper alloy: Copper alloy has a small friction coefficient and does not rust. It is one of the commonly used materials. For low pressure valves with Pg<1.6Mpa, ZHMn58-2-2 cast brass can be used.
2. Steel: When the working conditions do not allow the use of copper alloys, high-quality carbon steels such as 35, 40, 2Cr13, 1Cr18Ni9, Cr17Ni2 and other stainless and acid-resistant steels can be selected. The working conditions do not allow the following:
For electric valves, stem nuts with gua-shaped clutches require heat treatment to obtain high hardness or surface hardness.
When the working medium or the surrounding environment is not suitable for copper alloys, such as ammonia medium that is corrosive to copper.
When selecting steel stem nuts, pay special attention to thread seizure.

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

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

August 27, 2020

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

16 U-type-flange-butterfly-vlave-body

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	ASTM A217	-30/593	non-corrosive water, oil and gas
C5	5% chromium,0.5% molybdenum	ASTM A217	-30/649	light or non-corrosive application
C12	9% chromium 1% molybdenum	ASTM A217	-30/649	light or non-corrosive application
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

Posts

Introduction to Common Butterfly Valve Materials

Valve material comparison table-valve pressure-temperature

Valve material and valve standards-(9)- general valve & parts materials

Valve material and valve standards-(8)- Monel alloy application

Valve material and valve standards-(7)- Monel alloy

Valve material and valve standards-(6)-gasket material

Valve material and valve standards-(5)-packing material

Valve material and valve standards-(4)-fastener material

Valve material and valve standards-(3)-sealing material

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

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