A Fe-Ni-Cr alloy with excellent high temperature oxidation resistance
- Good material for high temperature oxidation resistance
- Maintains high strength at elevated temperatures
- A286 Chemistry, specs, and heat treatments
- Slip on flange features and benefits
A-286 slip on flanges are known for their high strength, creep resistance and oxidation resistance at elevated temperatures. This iron-nickel-chromium alloy (once age-hardened) provides A-286 slip on flanges with high levels of strength from room temperature up to about 1300°F (700°C).
A-286 slip on flanges are mildly corrosion resistant. While they should not be used for strong acid environments, they provide excellent oxidation resistance up to 1300°F (700°C) in conditions that would typically be found in high temperature exhaust streams.
Because of these properties, A-286 slip on flanges are often found in high temperature engine, manifold, exhaust and turbine applications as well as off-shore oil & gas applications.
A-286 Heat Treatments: There are several heat treatment combinations for A-286 all with slight variations in performance. They can be specified via an AMS number or a 660 Class: A, B, C or D, with most common specified as class A or D. The A-286 grades A, B and C all have the same min tensile strength and min yield strength of 130ksi and 85ksi respectively. However grade D is significantly better yield with a min tensile of 130ksi and a min yield of 105ksi.
By AMS numbers, the most common for A-286 is AMS 5737 (same as Grade A) and then AMS 5732 (same as Grade B).
A-286 Specifications: AMS 5525, AMS 5732, AMS 5737, AMS 5804, EN 1.4980, GE B50T1181, GE B50T12, GE B50T81, UNS S66286, Werkstoff 1.4980
A286 slip on flanges are similar to the socket weld flange but without the socket shoulder. When using a socket weld flange, the pipe rests against this internal shoulder. Since a slip on flange does not have shoulder, the pipe can slide completely through the flange hub and is free to spin.
- Typically lower in price than weld-neck flange, yet welding costs can be more.
- There is a reduced need to cut the pipe length accurately, making it easier to install.
- The slip on flange is free to spin on the pipe for easy bolt alignment.
- They require two fillet welds: one fillet weld at the hub of the flange and a second weld at the inside diameter of the flange near the flange face.
- Though they can be used for high temperature and pressure applications, they typically are not as other flange types give a more secure joint.