Views: 6 Author: Monica Publish Time: 2025-10-27 Origin: Site
ASTM B165 UNS N04400 seamless pipe is a corrosion-resistant pressure pipe made of nickel alloy. This standard outlines the size, tolerances, chemical makeup, and mechanical properties for seamless cold-finished and hot-finished pipes.
B165 seamless pipe usually follows size standards. These standards are set by the American National Standards Institute and the American Society of Mechanical Engineers.
These include ASME B36.10M and B36.19M. The nominal pipe size usually ranges from NPS 1/8 to NPS 8 or larger. Wall thicknesses are defined by different schedule numbers, like Sch 40, Sch 80, and Sch XS.
The main benefit of N04400 alloy is its strong resistance to seawater and brine corrosion. It also tolerates non-oxidizing acids well. Additionally, it keeps high strength and good toughness over a wide range of temperatures. These properties make it an ideal choice for marine engineering, chemical processing equipment, and the oil and gas industry.
UNS N04400 (Monel 400) is a nickel-copper alloy. According to ASTM B165, alloy 400 is primarily composed of nickel and copper. The nickel content must be at least 63.0%, while the copper content is typically between 28% and 34%.
UNS N04400 alloy strictly limits the content of impurity elements such as iron, manganese, and silicon. The sulfur content is kept very low. This helps prevent stress corrosion cracking and pitting corrosion in tough environments. It also ensures good machinability and weldability.
Composition | Value |
Nickel + Cobalt | ≥ 63.0 |
Copper | 28.0 - 34.0 |
Iron | ≤ 2.50 |
Manganese | ≤ 2.00 |
Carbon | ≤ 0.30 |
Silicon | ≤ 0.50$ |
Sulfur | ≤ 0.024 |
The ASTM B165 specification covers UNS N04400 (Monel 400) in the form of seamless pipe and tube. The B165 standard does not provide specific size requirements for these pipes. Instead, it refers to the industry piping codes for details on outside diameter and wall thickness.
The sizes for ASTM B165 pipes, including wall thickness based on the schedule number, follow ASME B36.10M and ASME B36.19M standards.
Monel 400 is often used in corrosive situations that need certain pressure ratings. The size chart below shows common Nominal Pipe Sizes (NPS) and their Schedule wall thicknesses. These are based on the standard dimensional tables from B165.
Nominal Pipe Size (NPS) | Outside Diameter (OD) [in / mm] | Schedule 10S Wall Thickness [in / mm] | Schedule 40S/STD Wall Thickness [in / mm] | Schedule 80S/XS Wall Thickness [in / mm] |
1/2" | 0.840 in / 21.3 mm | 0.083 in } / 2.11 mm | 0.109 in / 2.77 mm | 0.147 in / 3.73 mm |
1" | 1.315 in / 33.4 mm | 0.109 in / 2.77 mm | 0.133 in / 3.38 mm | 0.179 in / 4.55 mm |
2" | 2.375 in / 60.3 mm | 0.109 in / 2.77 mm | 0.154 in / 3.91 mm | 0.218 in / 5.54 mm |
4" | 4.500 in / 114.3 mm | 0.120 in / 3.05 mm | 0.237 in / 6.02 mm | 0.337 in / 8.56 mm |
6" | 6.625 in / 168.3 mm | 0.134 in / 3.40 mm | 0.280 in / 7.11 mm | 0.432 in / 10.97 mm |
8" | 8.625 in / 219.1 mm | 0.148 in / 3.76 mm | 0.322 in / 8.18 mm | 0.500 in / 12.70 mm |
Note: Dimensions are nominal. The B165 specification itself outlines the chemical, mechanical, and testing requirements for the UNS N04400 material but requires compliance with ASME dimensional standards for pipe sizing.
UNS N04400 alloy has a high density of approximately 8.80 g/cm³, significantly higher than stainless steel. Its melting point typically ranges from 1300°C to 1350°C.
Monel 400 offers good thermal conductivity, superior to austenitic stainless steels, and a relatively low coefficient of thermal expansion.
Mostly, Monel 400 alloy is non-magnetic in the solution-annealed state.
Property | Typical Value |
Density | 8.80 g/cm3 |
Melting Range | 1300 - 1350 ℃ |
Thermal Conductivity | 21.8 W/(m·℃) |
Specific Heat | 427 J/(Kg·℃) |
Magnetic Permeability | ~ 1.00 |
UNS N04400 excels in low- and medium-temperature applications. It cannot be hardened by heat treatment and can only be strengthened by cold working.
In the standard annealed condition, Alloy 400 has a minimum tensile strength of about 550 MPa. It also has a minimum yield strength of around 240 MPa. This alloy maintains good ductility.
Tensile Strength | 550 MPa |
Yield Strength | 240 MPa |
Elongation | 35% |
Modulus of Elasticity | 179 GPa |
Recent prices for ASTM B165 UNS N04400 Monel 400 seamless tubing are between $20 and $25 per kilogram. This is for a minimum order of 100 kg. Some offers are lower, ranging from $16 to $25 per kilogram for a minimum order of 300 kg. Additionally, some suppliers quote factory-direct prices between $29.70 and $39.60 per kilogram.
The price of ASTM B165 UNS N04400 seamless pipe is mainly based on several factors. These include material costs, production methods, specifications, dimensions, order size, and quality certifications. The main material, Monel 400, has strong resistance to corrosion and heat. This leads to high raw material costs.
Regarding production processes, seamless pipes are typically manufactured using techniques such as extrusion or piercing. These processes are complex and demand high-specification equipment, directly impacting production costs.
Product specifications and dimensions also contribute to price variations, with non-standard or custom products commanding significantly higher prices than standard offerings.
Furthermore, purchase volume is a key factor affecting unit pricing, as bulk orders typically secure more favorable rates.
Finally, obtaining reliability certifications such as ISO, CE, or SGS also impacts pricing. Certified products offer greater quality assurance and consequently carry higher price tags.
The pressure rating of Monel 400 seamless pipe is not a set number. It mainly depends on the pipe's outer diameter and wall thickness.
Pressure rating calculations typically follow industry-standard specifications, such as ASME B31.3, the Pressure Piping Code. Monel 400 is a strong nickel alloy. It can handle high pressure well. This alloy works great in tough environments that need resistance to corrosion.
O.D. [inch] | Wall Thickness [inch] | Maximum Allowable Working Pressure [PSI] |
1/8 in | 0.028 in | 8,000 |
1/8 in | 0.035 in | 10,450 |
1/4 in | 0.035 in | 4,800 |
1/4 in | 0.049 in | 7,000 |
3/8 in | 0.049 in | 4,450 |
1/2 in | 0.035 in | 2,300 |
1/2 in | 0.049 in | 3,300 |
1 in | 0.065 in | 2,250 |
