Overview
A super duplex steel cap refers to a specific type of cap fitting made from super duplex stainless steel. Super duplex stainless steel is a higher grade of duplex steel that offers even greater corrosion resistance and mechanical strength compared to standard duplex stainless steel.
Super duplex steel caps are suitable for use in environments that require exceptional resistance to corrosion, such as offshore platforms, chemical processing plants, and seawater applications. The higher levels of chromium, molybdenum, and nitrogen in the super duplex stainless steel composition enhance its resistance to pitting, crevice corrosion, and stress corrosion cracking.
Similar to duplex steel caps, super duplex steel caps are manufactured in compliance with relevant standards such as ASTM A815. These caps come in various sizes, dimensions, and end connections to fit different pipe diameters and system requirements.
Super duplex steel caps are typically installed by welding methods such as socket welding or butt welding, ensuring a secure and leak-proof connection. It is crucial to select the appropriate welding procedure and consumables that are compatible with the super duplex steel material to maintain its superior properties.
In summary, a super duplex steel cap is a specialized cap fitting made from super duplex stainless steel, offering exceptional corrosion resistance and mechanical strength. It is commonly used in industries and applications where standard duplex stainless steel caps may not provide sufficient durability and protection against corrosion.
ASTM A815/A815M-20 Standard Specification for Wrought Ferritic, Ferritic/Austenitic, and Martensitic Stainless Steel Piping Fittings.
Specifications | ASTM A815 / ASME SA815 |
Size | Seamless Butt Weld Fittings: 1/2″ – 24″, Welded Butt Weld Fittings: 1/2″ – 48″ |
Standards | ASME/ANSI B16.9, ASME B16.28, MSS-SP-43 |
Thickness | 5s, 10s, 40s, 80s, 10, 20, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS available with NACE MR 01-75 |
Type | Seamless / Welded / Fabricated |
Chemical Composition
Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N | Fe |
S32750 | 0.030 max | 1.20 max | 0.80 max | 0.035 max | 0.020 max | 24.00 – 26.00 | 3.00 – 5.00 | 6.00 – 8.00 | 0.24 – 0.32 | 58.095 min |
Mechanical Properties
Grades | Density (g/cm 3) | Density (lb/in 3) | Melting Point (°C) | Melting Point (°F) |
S32750 | 7.8 | 0.281 | 1350 | 2460 |
Applications