SPECIALITY ALLOY VALVES A20/MONEL

Forged Alloy 20 (ASTM A182 F20) and it’s cast equivalent A351 CN7M is a speciality grade of Austenitic Stainless steel often referred to as ‘super’ stainless steels. Forged Monel 400 (UNS N14400) and it’s cast equivalent A494 M35-1 are Nickel Copper Alloy Steels as is Monel K500. Global Supply Line can also supply valves manufactured in other Nickel Alloys such as 600, 625, and 825. We can also supply other material grades of valves like hastelloy, titanium, etc.

ALLOY 20 (A20)

Alloy 20 resists acid, general pitting attack, and chloride stress corrosion cracking. Ideal for fabrication and possessing exceptional mechanical capabilities. Alloy 20 can be welded with minimal carbide precipitation due to the inclusion of columbium. Alloy 20 is widely accepted for uses as diverse as chemical pharmaceutical processing, food, petrochemical and gasoline, solvents, plastics, synthetics, and explosives.

Cast Alloy 20 grade A351-CN7M is suitable for service -46ºC to 150ºC. ‘New Alloy 20’ cast grade A990-CN3MCu is suitable for -29ºC to 320ºC. Global Supply Line now also stocks CN3MCu. Forged Alloy 20 ASTM A182-F20 and B462 Grade N08062 (35Ni-35Fe-20Cr-Cb) is suitable up to 316ºC.

Design Features

• Exceptional stress-corrosion resistance in boiling 20% to 40% sulfuric acid
• Sulfuric acid general corrosion resistance
• Ideal fabricability and mechanical characteristics
• Welding products minimal carbide precipitation

Applications

• Chemical and allied industries
• Pharmaceutical processing
• Food and dye
• Sulfur dioxide (SO2) scrubbers
• Pickling racks
• Tanks
• Severe environments

Applications

FORGING SPECIFICATION	COMMON DESIGNATION	MATERIAL SUFFIX	WROUGHT BAR SPECIFICATION	SERVICE RECOMMENDATIONS (1)	COMMON API TRIM # FOR BASE MATERIAL
					150 TO 600 #	900 TO 2500 #
ASTM B462 N08020	20% Chrome; 28% Nickel; 3-1/2% Cu, 2-1/2% Mo  Super Stainless Steel	ASTM A351 Grade CN7M (A20)	ASTM B473 N08020	Acetic acid (hot), brines, caustic solutions, (strong, hot), hydrochloric acid (dilute), hydrofluoric acid and hyrdofluosilicic acid (dilute), nitric acid, (strong, hot), nitric-hydrofluoric pickling acids, sulfates and sulfites, sulfuric acid, all concentrations to 150ºF (65.5ºC), sulfurus acid, phosphoric acid.	13	14

Alloy 20 Chemical Composition

C	Cb	Cr	Cu	Mn	Mo	Ni	P	S	Si	Ta
MAX	8 Times			MAX			MAX	MAX	MAX	8 Times
0.07	Carbon-1.00	19.0-21.0	3.0-4.0	2.0	2.0-3.0	32.0-38.0	0.045	0.035	1.0	Carbon-1.00

MONEL

Monels are a Nickel alloy material with the addition of copper (Cu), Silicon (Si) and Maganese (Mn). These materials are also known as Monel, Alloy 400 and Alloy K500.

Common Material Specifications

Ni Cu30 Fe3.5 Si1.5(+) (Monel 400)

• A494 M-35-1 (UNS N24135) (Low Si – weldable)
• A494 M-35-2 (UNS N04020)
• BS3071 : NA1
• BS3071 : NA3

Others

• Wrought equivalent Alloy 400 (UNS N04400)

Typical Properties

• Tensile 430 N/mm2
• Yield 170-205 N/mm2
• Elongation 20-25%
• Hardness HB 100-150
• Density 8.8 g/cm3
• Pressure temperature rating: B16.34 Group 3.4

Corrosion Properties

• Good general corrosion for seawater service
• Especially good for higher flow rates
• Excellent trim material for NAB, gains cathodic protection with many alloys
• Not recommended for low velocities

Additional Uses

• Variety of wrought/ bar specifications available, good for trim material. Excellent strength from K500
• Used for oxygen service
• Welded with lower Si content
• Excellent for hydrofluoric & other acids (not nitric)

Cautions

• Ease of manufacture: trade-off between castability and weldability
• Pitting can be a problem at low velocities
• Don’t use as trim for austenitic stainless

ASTM A296 gr. M-35 Monel (Monel 400) Chemical Composition

C	Cb	Cr	Cu	Mn	Mo	Ni	P	S	Si	Ta
MAX	8 Times			MAX			MAX	MAX	MAX	8 Times
0.07	Carbon-1.00	19.0-21.0	3.0-4.0	2.0	2.0-3.0	32.0-38.0	0.045	0.035	1.0	Carbon-1.00

Applications

FORGING SPECIFICATION	COMMON DESIGNATION	MATERIAL SUFFIX	WROUGHT BAR SPECIFICATION	SERVICE RECOMMENDATIONS (1)	COMMON API TRIM # FOR BASE MATERIAL
					150 TO 600 #	900 TO 2500 #
ASTM B564 N04400	67% Ni; 30% Cu, Monel	ASTM A494 Grade M-35-1 (Monel)	ASTM B164 N04400	Weldable grade. Good resistance to corrosion by all common organic acids and salt water. Also high resistant to most alkaline solutions to +752ºF (+400ºC).	9, 11	9, 11